HARVARD UNIVERSITY Library of the Museum of Comparative Zoology ,Q,OD/s MnberS (»EAT BASIN NATURALIST MEMOR Brigham Young University 1! Utah Lake Monograph^^ GREAT BASIN NATURALIST Editor. Stephen L. Wood, Department of Zoology, Brigham Young University, Provo, Utah 84602. Editorial Board. Kimball T. Harper, Botany; Wilmer W. Tanner, Life Science Museum; Stanley L. Welsh, Botany; Clayton M. White, Zoology. £.v Officio Editorial Board Members. A. Lester Allen, Dean, College of Biological and Agricul- tural Sciences; Ernest L. Olson, Director, Brigham Young University Press, University Editor. The Great Basin Naturalist was founded in 1939 by Vasco M. Tanner. It has been published from one to four times a year since then by Brigham Young University, Provo, Utah. In gener- al, only previously unpublished manuscripts of less than 100 printed pages in length and per- taining to the biological and natural history of western North America are accepted. The Great Basin Naturalist Memoirs was established in 1976 for scholarly works in biological natu- ral history longer than can be accommodated in the parent publication. The Memoirs appears irregularly and bears no geographical restriction in subject matter. Manuscripts are subject to the approval of the editor. Subscriptions. The annual subscription to the Great Basin Naturalist is $12 (outside the United States $13). The price for single numbers is $4 each. All back numbers are in print and are available for sale. All matters pertaining to the purchase of subscriptions and back num- bers should be directed to Brigham Young University, Life Science Museum, Provo, Utah 84602. The Great Basin Naturalist Memoirs may be purchased from the same office at the rate indicated on the inside of the back cover of either journal. Scholarly Exchanges. Libraries or other organizations interested in obtaining either journal through a continuing exchange of scholarlv publications should contact the Brigham Young University Exchange Librarian, Harold B. Lee Library, Provo, Utah 84602. Manuscripts. All manuscripts and other copy for either the Great Basin Naturalist or the Great Basin Naturalist Memoirs should be addressed to the editor as instructed on the back cover. iREAT BASIN NATURMIST MEMOIR! Brigham Young University 19( Utah Lake Monograph CONTENTS Preface. Richard A. Heckmann and Lavere B. Merritt 1 Physical and Cultural Environment of Utah Lake and Adjacent Areas. Richard H. Jack- son and Dale J. Stevens 3 Geology of Utah Lake: Implications for Resource Management. Willis H. Brimhall and Lavere B. Merritt 24 Hydrology and Water Quality of Utah Lake. Dean K. Fuhriman, Lavere B. Merritt, A. Woodruff Miller, and Harold S. Stock 43 Aquatic and Semiaquatic Vegetation of Utah Lake and Its Bays. Jack D. Brotherson 68 Phytoplankton of Utah Lake. Samuel R. Rushforth, Larry L. St. Clair, Judith A. Grimes, and Mark C. Whiting 85 Macroinvertebrate and Zooplankton Commimities of Utah Lake: A Review of the Liter- ature. James R. Barnes and Thomas W. Toole 101 Fishes of Utah Lake. Richard A. Heckmann, Charles W. Thompson, and David A. White 107 Terrestrial Vertebrates in the Environs of Utah Lake. Clyde L. Pritchett, Herbert H. Frost, and Wilmer W. Tanner 128 No. 5 Great Basin Naturalist Memoirs Utah Lake Monograph Brigham Young University, Provo, Utah 1981 PREFACE Richard A. Heckniann' and Lavere B. Menitt' Utah Lake is the largest freshwater lake in the United States west of the Mississippi Riv- er. It covers approximately 39,000 ha (150 miles^) and contains about 1.11 X lO^m^ (900,000 acre-feet) of water. It is a remnant of Lake Bonneville, which occupied most of western Utah until about 7250 BC. The lake is fed by several streams, including the Provo and Spanish Fork Rivers, and is drained by the Jordan River into the Great Salt Lake. The three groups of Indians, Paiutes, Utes, and Shoshones, that utilized the areas around Utah Lake were nomadic and used it primar- ily for fishing and hunting. They were largely displaced, commencing in 1849, by the Mormon pioneers, who tilled the land, spread the mountain streams for irrigation, in- troduced grazing animals, and effectively changed the natural balance of plants and an- imals. In an effort to increase the fish produc- tion, they also introduced several species of fish into the lake. Such actions profoundly af- fected Utah Lake and drastically modified its biota. Other uses of the lake included barge transportation, water transportation, boating, and recreation. At one time, 15 resorts exist- ed around it. The aesthetic quality of the lake is an important element of Utah Valley. In 1978 a group of biological and physical scientists met and discussed various questions that relate to Utah Lake— for example, what are the potentials for Utah Lake as a multiple-use resource? Is it possible through sound research and proper management to insure that future manipulation and use of the lake will be beneficial? Can maximum use of this resource be achieved and not de- tract from its utility and beauty? As a re- source facing multiple demands, should any one use be given top priority? The consensus of the group was that the best way to ap- proach these questions would be to prepare a volume that reviews and summarizes data pertaining to the lake. This goal is realized in the present volume. This volume is divided into three parts: (1) the history of Utah Lake, (2) physical and cli- matic factors of the area, and (3) biology of the lake. Each article is written by invitation to scientists and historians who have made significant contributions to our knowledge of Utah Lake. A wealth of renewable natural resources occur in and around Utah Lake. Not only can these resources be utilized now, but with proper management they will be available indefinitely. It is our hope that this volume will serve as a base for future studies of this valuable ecosystem. We feel strongly that Utah Lake should be carefully guarded and enjoyed, since it is a valuable asset to Utah Valley. Acknowledgments We express thanks to the following who have donated funds for the publication of this monograph; BYU Research Division, BYU 'Department of Zoology, Brigham Young University, Provo, Utah 84602. -Department of Civil Engineering, Brigham Young University, Provo, Utah 84602. 2 Great Basin Naturalist Memoirs No. 5 College of Engineering Sciences and Tech- Provo-Jordan Parkway Authority, Eyring Re- noloev BYU Center for Health and Environ- search Institute, BYU Environmental Analysis mental Studies, BYU Departments of Civil Laboratory, and Utah Division of Wildlife Engineering, Geography, and Zoology, Resources. PHYSICAL AND CULTURAL ENVIRONMENT OF UTAH LAKE AND ADJACENT AREAS Richard H. Jackson' and Dale J. Stevens' .\bstract.— Utah Lake and its surrounding area have a rich natural and cultural background. The moderate cli- mate, abimdant fresh water, and fertile soils of Utah Valley made it an oasis to aboriginal dwellers as well as to the present inhabitants. An overview of the physical setting, geology, climate, human use, and recent hi.story of Utah Lake is presented. Physical Setting The basins and ranges of the Great Basin in the western United States have as their east- em border in central Utah a fertile valley rimmed by majestic mountains containing one of the largest freshwater lakes west of the Mississippi River. This lake, known as Utah Lake, occupies over 25 percent of the valley floor, and, even though it covers about 38,075 ha (150 mi^) and contains approx- imately 1100 X 106m3 (870,000 ac-ft) of wa- ter, its average depth is only 2.8 m (9.2 ft). The major perennial streams that feed the lake have their headwaters in the Wasatch and Uinta Mountains to the east. They are from north to south the American Fork Riv- er, Provo River, Hobble Creek, and Spanish Fork River. There are also a few minor per- ennial streams, many intermittent streams, and numerous springs and surplus water from pumped and flowing wells that add to the lake's volume. The total natural catchment area that drains water into Utah Lake is about 5957 km2 (2300 mi2). Demands for irri- gation water in Utah Valley result in addi- tional water entering Utah Valley from the Weber River, Duchesne River, and Straw- berry River via diversion canals and tunnels. The annual surface flow into Utah Lake from all monitored sources is slightly over 640 X 106m3 (520,000 ac-ft) (Hudson 1962:75). Lo- cation of the major surface streams that feed Utah Lake are shown in Figure 1. The Jordan River flowing into the Great Salt Lake is the sole outlet of Utah Lake. The mountains that rim Utah Valley rise rather abruptly from the valley floor, reach- ing altitudes of about 457 m (1,500 ft) to nearly 2,286 m (7,500 ft) above the 1,368 m (4,489 ft) lake surface. In the lower parts of the valley a semiarid climate is found, but it gives way to wetter and cooler conditions higher up the mountain slopes. The highest peaks are well above timber line, but per- petual snow and ice are not found on any nearby mountain summits. Some snow banks remain from one year to the next, but most of these disappear during the average summers. The different climatic types are reflected in the native vegetation zones from the val- ley floor to the mountain summits. Sagebrush and grasses dominate the lower areas, giving way to mountain brush, juniper and aspen, next to coniferous trees and eventually alpine grasses, and then sedges in the highest places. Trees and other riparian vegetation are found along most water courses, but much of the shore of Utah Lake is devoid of trees. The shallow margins of the lake contain a variety of vegetation, with Provo Bay being domi- nated by rushes and cattails. Since settlement of the valley by people of European ancestry, most of the area has been transformed into cultivated land, cities, and towns. Of all the Great Basin valleys, Utah Valley is the most agriculturally productive. The mountain slopes still contain some natu- ral vegetation, but man's activities have al- tered the area considerably. Dust storms oc- casionally add considerable particulate matter to the atmosphere, but man-made pol- 'Department of Geography, Brigham Young University, Provo, Utah 84602. Great Basin Naturalist Memoirs No. 5 Fi^. 1. Utah Lake drainage basin. 1981 Utah Lake M ono(;raph lutants tend to create a near-permanent haze over the valley, especially in winter months. The name Utah (after the Ute Indians who were occupying Utah Valley when the first settlers came to the area in 1847) was first given to the county and the lake before it was applied to the territory and ultimately the state in 1896. Geologic Origins For the last 70 million years crustal stresses, marine erosion and deposition, and volcanic activity have all added to the char- acter of the existing landscape. The Rocky Mountain system, including the Wasatch Range that borders Utah Valley and Utah Lake on the east, had its beginnings when two large sections (plates) of the earth's sur- face were forced together causing the exist- ing sediments to be lifted to lofty mountains. This crustal deformation occurred over sever- al million years, with periods of relative calm and downwear between the tectonic activity (Brimhall 1973:121). About 35 million years ago volcanic activi- ty, centered north and south of Utah Valley in the Tintic and Oquirrh Mountains, re- sulted in mineralization of these areas (Hintze 1973:80). Today the major mining districts of central Utah are centered in these areas. As time passed, further stresses caused blocks of the earth's crust to be uplifted and downfaulted. These uplifted blocks form the present mountains of the Basin and Range Province, with the Wasatch Mountains being the easternmost of the group. Many of the intermountain basins, such as Utah Valley, are downfaulted (grabens) and are filled with more recent marine and alluvial deposited sediments. A distinct feature of the local block fault- ing is the high angle of the faults, which have created rather abrupt mountain fronts. De- bris eroded from the uplifted ranges have gradually filled in the intermountain basins until today these sediments have accumu- lated to thousands of feet in depth in many basins. Perhaps the most unique aspect of the local faulting is the presence of numerous triangular faceted spurs in the proximity of the Wasatch fault zone. Interfluve ridges of the Wasatch Mountains that would normally extend to the valley floor are interrupted by recurrent fault lines at right angles to the ridge. Resulting faceted spurs or "flatirons" usually exist in somewhat of a hierarchy, with the largest and oldest occurring farther up the mountains from the smaller more recent triangle facets near the base. Maple Moun- tain to the east of Mapleton is a prime ex- ample of these faceted spurs. The flatness of the floor of Utah Valley is due to lacustrine sediments of a much larger lake than Utah Lake. This large lake, known as Lake Bonneville, occupied much of west- ern Utah until about 8,000 BC. It was one of several Pleistocene lakes in the western U.S. Some of the most conspicuous landforms in the vicinity of Utah Lake are the remnant terraces left by this ancient lake that prob- ably began filling the valley about 75,000 years ago (Bissell 1968:11). Fluctuations in the level of the lake, caused by climatic changes, resulted in the formation of distinct terraces or benches on the mountainsides where the shoreline remained long enough to etch out and deposit beach sediments. The first high level of the lake was at 1,555 m (5,100 ft) and is known as the Alpine Level (Bissell, 1968:3). The lake probably remained at this level for several thousand years before rising to 1,565 m (5,135 ft) due to wetter con- ditions. The water continued to rise to at least 1,585 m (5,200 ft) with the capture of the Bear River to the north, then spilled over through Red Rock Pass in southern Idaho into the Snake River. After tremendous vol- umes of water pushed on through the Snake and Columbia Rivers, the lake stabilized at the 1,463 m (4,800 ft) level (Bissell 1968:3). It was during this period that large deltas were built into the lake by the major inflowing streams, creating the "bench land " of eastern Utah Valley. This level has been designated as the Provo level. As time passed, drier and warmer condi- tions prevailed and evaporation rates began to exceed the inflow rates, resulting in a de- crease in size and, eventually, a separation into at least two distinct lakes. What is now Utah Lake remained as a temporary catch- ment basin for fresh water entering the larger Great Salt Lake via the Jordan River. Layers of sand, gravel, silt, and clay under- lay Utah Valley and correlate with several glacier periods when Lake Bonneville cov- 6 Great Basin Naturalist Memoirs No. 5 ered the area. Most of the gravel beds are as- sociated with deltas and alluvial fan deposits that are adjacent to the mountain front. Silts and clays are more common in the central part of the valley (Brimhall 1973:2). The ac- companying maps from a recent study (Figs. 2 and 3) show the general character of the lake bottom and the surrounding geology (Jensen 1972:41, 46). Because of the position of Utah Lake in the western part of the val- ley, its eastern shore is mostly poorly drained and has a gentle slope, but most of the west- em shoreland rises rapidly as the eastern front of the Lake Mountains. Weather The factors that account for the type of weather conditions and ultimately the cli- mate in the vicinity of Utah Lake are: 1. Its inland position is 1,050 km (650 mi) from the Pacific Ocean and about 1,850 km (1,150 mi) from the Gulf of Mexico. 2. Its elevation above sea level is about 1,372 m (4,500 ft). 3. Its position is adjacent to the abrupt, sloping Wasatch Mountains. 4. The prevailing winds of the area are westerly. 5. Frequent frontal contact of polar and tropical air masses with accompanying cyclonic storms are experienced. Because of the interaction of these factors, the precipitation in the vicinity of Utah Lake is relatively light, there is a wide variation in temperature, the relative humidity is nor- mally low, there is abundant sunshine with some exceptions in winter and spring, and winds normally blow from the west to north- west, although there are frequent deviations from this direction. Early morning canyon downslope breezes move into the valley, es- pecially from Provo and Spanish Fork Can- yons. Advection fog often occurs in the win- ter months near the shore of Utah Lake and other lower portions of the valley. Snow depths in winter may reach up to 30 cm (11.8 in), with total snowfall averaging about 1 m (3.3 ft) per year. In 1972 Spanish Fork re- corded a record total of 3.72 m (148 in) of snow. Snow depths are usually greatest in this southern part of the valley. Although winds in excess of hurricane ve- locity (121 kph or 75 mph) are not common. they occasionally occur but are not associ- ated with the tropical hurricanes that invade the southern coast of the U.S. Tornadoes are rare in Utah, but normally one or two are sighted per year in the state. None have been officially reported in the vicinity of Utah Lake. During the summer months dust devils (whirlwinds) carry dust and other debris into the air, but they rarely cause any damage. Winds blowing off the deserts to the west of- ten bring with them considerable quantities of dust, which give a haze to the valley. If a rainstorm follows one of these dust storms, muddy rain can be expected. Of all the elements of weather, precipi- tation and temperature are usually consid- ered most important to the biotic community that is dependent on favorable quantities of each. Each of these will be discussed briefly. Precipitation The influx of moist air into the Utah Lake area usually originates over the Pacific Ocean during the winter and spring months and moves in with cyclonic storms usually originating in the Gulf of Alaska. These fron- tal storms are normally short-lived but occa- sionally result in more than 2.54 cm (1 in) of precipitation. As a cold front passes, the wind will normally shift from the south to the north. There is an obvious decrease in tem- perature, with gusty winds and rain or snow for several hours before the storm moves eastward and out of the area. Nearly 60 per- cent of the total annual precipitation occurs in the late winter and early spring, with March being the wettest month (Utah Clima- tological Data, 1950-1975). The storm track moves northward during the summer months, and the change in pres- sure patterns allows moist air to move in from the Gulf of Mexico. Because of the rela- tively high temperatures of summer, con- vectional storms are more common than frontal storms. Thunder and lightning accom- pany the large cumulonimbus clouds, which may drop heavy amounts of rain and/or hail. Hailstones are usually less than 1 cm (0.4 in) in diameter. August is the wettest summer month, with receipts averaging about 2.54 cm (1 in) (Utah Climatological Data, 1950-1975). 1981 Utah Lake Monograph i ^.^^^ N {' \\ '■■ \\> ^ '•• ,. ^:\|_ if / rJ •■■"'''' '''-■•'■'""''' ^ ■■ ^^"^ M< // "'■ ,, W yCyT'^ r 1 \ '""■ ^ ^#^ -.J % v./% Contours bekw olevalion 4480 compiled from enm-seclioni X through the ke, 1962-1963. \fv/r Doto; Boreoo of Reclomatior> r / Fig. 2. Utah Lake topography. During an average year, total precipitation varies from just over 23 cm (9 in) near the eastern shore of Utah Lake at the Geneva Steel Plant to over 45.7 cm (18 in) at Santa- quin near the southern shore of the lake. In the nearby mountains, receipts averaging up to 127 cm (50 in) per year are common and are major source areas of Utah Lake water. Great Basin Naturalist Memoirs No. 5 Fiy;. 3. Surfuff i^eolo^y in tlic vici Utah Lak id near the lake margins Evaporation from Utah Lake, although con- perature over anc siderable, seems to have no appreciable ef- Table 1 gives some monthly data on six s a- fect on local precipitation, although it does tioiis that border Utah Lake (Utah Chmatolo- have some influence on humidity and tem- gical Data, 1950-19/5). 1981 Utah Lake M ONOGRAPH Temperature Variation is perhaps the key word in de- scribing temperature from place to place and from one season to the next in the valley. The transition from summer to winter and from winter to summer is usually quite rapid. There are distinct times of the year when springlike and autumnlike weather occur, but these "seasons" are best described in weeks of time rather than months. Average maximum July temperature is about 33 C (92 F), and the average minimum for the same month is 12 C (53 I). In the coldest month, January, the average maximimi temperature is about 3 C (37 F), and the average minimum is ap- proximately -10 C (14 F). Temperatures of over 38 C (100 F) are likely to occur during a few days of summer and drop to less than -26 C (-15 F) during a few days of the winter months (Table 1). The geographical variation of temperature is seen in the growing season for three areas within Utah Valley. At Provo the growing season is 126 days; at Utah Lake-Lehi it is 132 days; and at Spanish Fork it is 167 days (Ashcroft 1963:28-33). Mountain and valley breezes and air inversion layers give partial explanation to these values, but location within the valley, proximity to the lake, alti- tude, etc., all help explain the differences. The charts below (Fig. 4) show probable dates of critical temperatures during the spring and fall for Lehi at the north end of Utah Lake and at the Provo Airport near the eastern shore. Climate Much of the early legend about the cli- mate of central Utah and contemporary con- cepts nonresidents and residents alike have today about it is that Utah Valley is a desert (but may have been changed by man) or that it is part of a large desert that extends west- ward to the Sierra Nevadas. By all standards of measurement, however, Utah Valley is not a true desert. In fact, the eastern part of the valley is considered to have a humid climate. A more apt description of the greater part of the valley is a cool winter steppe or semi- arid climate. The boundary between this and the humid continental climate near the base of the Wasatch Mountains is determined by a comparison of total precipitation, including seasonal variation and potential evapo- transpiration. Where the former is greater than the latter, a humid climate exists and vice versa. Provo Airport / / / / / ^ / / - f\ / / / > / r f y 4^ y •^. t 4} /■ / / / / / / A / / / J / ^ / / /^ *" \ \ \ \ \ \ \ \ \ \ \ s t' ^ sT ^ 7. ' t t > \ \ V s \ \ \ \ \ ^ \ \ \ N \ \ 20 25 30 5 10 15 20 25 30 5 10 15 20 25 30 5 10 15 March I April I May I June 5 10 15 20 25 30 5 10 15 20 25 30 5 10 15 20 25 September I October l November Utah Lake-Lehi 7 n / y Y 7 5 - 10 I20 30 40 \ \ \ \ \ 1 i / / / / / / / \ \ \ \ \ N T 4 / n 5> a t , y^ X- ^ 1 '■^ % % % / / / / / \ \ \ \ \ / / / / / ^ \ \ \ / / A / / \ \ \ \ \ \ 5 10 15 20 25 30 5 10 15 20 25 30 5 10 15 20 25 30 September I October I November I Fig. 4. Probabilities of first and last freezing dates at Provo Airport and Utah Lake-Lehi. 10 Great Basin Naturalist Memoirs . _mi» (/i-or--nm> -a -^ n a -• 3 tto5-*-cr^ !r^!2C -a t It oi --3 ttoa---. errs 5<^. t«t No. 5 S 2 - -. » -• 00 OJ oj ^o o^ 00 3 ro o» >o OJ ro ul O" 3<-».TfO-I -••O -«i- -1. — ' 3 o^ vo o "X) ro ro — > vO 00 o^ o O ON CT^ CT» o^ CT» cr^ C -1 c i o o O o 1 3 19.9 15.3 5.6 12.5 13.1 18.5 -n 3- > 3 i 14.4 12.2 10.0 9.8 18.9 15.6 a f 3 > t- -o m n ? 5;5^s^^ S3; 3 S;5 i5o S £ O Iji — Oi Ji fvi In -~J b --J >£> tn 2. ssiss tS) o o" i'SS:^ 'U^ 00 !& Ln b J:» -J ■& 522SS5 TO 'j:. 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CT OJ *> 00 00 O IV) 2 VO (Jl CD 00 O ■ b b CTi rv> .c» 00 3 tyi ^ — U) rv) Ul 3 Ul Ul OJ U) Ul i£> Q" .-J O OJ en O o — ' CO o OO *^ e3 00 1981 Utah Lake Monograph 11 Other Natural Features Besides climate and land surface forms, soils and biota should be included in any dis- cussion of the local physical geography. Be- cause man has used and altered the more de- sirable areas of Utah Valley for crop production, towns, etc., the natural soil and biotic systems have been disturbed consid- erably since the early settlement period. The first settlers found most of the valley covered with grasses except where streams provided enough extra water for trees and other ri- parian vegetation. The hill slopes were prob- ably not too different from what one sees today except there was less sagebrush and probably more grass on the lower slopes. In their quest to establish a permanent home here, the settlers tilled the land, spread the mountain streams over the soil to irrigate their land, grazed the hill slopes, and effec- tively changed the natural balance of plants and animals. They both inadvertantly and purposely introduced many varieties of plants and animals that formerly did not exist here. The most recent soil survey of Utah Coun- ty lists six soil orders in the study area. The most dominant are the Mollisols, which have a thick, dark-colored surface layer that is 1 percent or more organic matter and a base saturation of 50 percent or more (Swenson et al. 1972:134). Most of the good farm land is of this type. Other orders that are found here are Alfisols, which are poorly drained soils with saline or alkaline conditions; the Histo- sols, which are bog soils found near the lake shore and other marshy areas; and Aridisols, which are found in the drier places. Aridisols have a strong lime horizon within 100 cm (40 in) of the surface, and Inceptisols and Entisols are soils that have only recently begun to de- velop because of recent deposition of allu- vium (Swenson et al. 1972:134-136, 164). The irrigated farm land of Utah Valley produces alfalfa, grain, and corn silage as main crops. Much of the bench land is planted to fruit trees, especially cherries, peaches, apples, and pears. Home gardens are quite common, and many varieties of vegetables and fruits are grown in these non- commercial ventures. Most of the natural vegetation has been re- placed by cultivated crops, imported weeds, and landscaped yards with their wide vari- eties of plants. In spite of the above- mentioned changes, Utah Valley is an impres- sive place to view after having traveled through surrounding areas. The Spanish fa- thers named it Paradise Valley in 1776. The current residents may not call it by such an exotic name, but it does have many amenities that make it stand out like an oasis in a desert. Human Use Utah Lake and its associated streams and lake plains have been of importance to man for at least several millenia. The earliest known inhabitants of the lake plain area were the so-called desert culture of the American Indian peoples (Jennings 1960a:4). The desert culture people occupied the Great Basin and the valleys at the foot of the Rocky Mountains in the period from approx- imately 10,000 BC to 300-500 AD (Jennings 1960a:4). Evidence of the desert culture has not been discovered in and around Utah lake, but remains of the desert culture group have been found at Danger Cave in western Utah dating from approximately 8,000 BC (Jen- nings 1960a:8). The desert culture people were limited in numbers and led a life de- voted to a search for food in the Great Basin and the rivers and streams and lakes associ- ated with it. Their use of Utah Lake was re- stricted to hunting for game on the plains of Utah Valley and to occasional catching of fish in the rivers during spawning season (Montillo 1968:39). The basic culture in the Utah Lake area for which extensive archaeological evidence has been discovered is the Fremont culture (Wormington 1955). In the Utah Valley area, the Fremont culture consisted of small groups engaged in the production of com, squash, and beans; hunting and gathering; and relatively intensive fishing by those resid- ing adjacent to Utah Lake. The lakes and riv- ers entering it were important sources of fish for the Fremont culture, as evidenced by bones found in archaeological sites on and around the lake (Montillo 1968). These In- dians caught fish in the streams primarily during the spawning season. Numerous sites 12 Great Basin Naturalist Memoirs No. 5 of the Fremont culture exist around the shores and river mouths of Utah Lake. At least 36 sites have been located on the Provo River in the area west of present-day Provo (Montillo 1968:6). Other sites have been found on the lower Spanish Fork River, Goshen Bay, the Peteetneet River near Pay- son, the American Fork River, and the Jordan River, as well as at sites along the lake shore (Jennings 1960b:212). The Fremont culture occupied the area around Utah Lake from 800 to 1600 AD (Montillo 1968:34), until the great drought of 1400 led to difficulty in subsistence, and the Fremont culture groups ultimately moved to the central plains of the United States (Mon- tillo 1968:35). Following the migration of the Fremont culture, other Indian groups moved into the area. At the time of occupation of the area by Anglos in the mid- 1800s, three groups of In- dians utilized the area around the lake. These represented the Paiute groups from the west- ern side of Utah Lake and the Great Basin, the Ute Indian tribes periodically occupying the Utah Lake plains and the Provo, Spanish Fork, and American Fork river areas on the eastern shores as they migrated; and the Sho- shone Indians, whose center was north in the Cache Valley, but who occasionally came into the area. These groups were nomadic and utilized the lake and rivers entering it for hunting and fishing. The first written records relating to Utah Lake and adjacent lake plains come from the records kept of the Dominguez and Velez de Escalante expedition. Dominguez and Velez de Escalante left New Mexico in late July 1776 in search of a direct route to Monterey, California. In the course of their travels they came down Spanish Fork Canyon and into Utah Valley, entering the valley on 23 Sep- tember 1776 (Jensen 1924:17-20). Domin- guez and Velez de Escalante provided a de- scription of the Indian residents of the lake at the time of their arrival and indicated the im- portance of fishing to the Indian people. Be- cause of the reliance of the people on fish, Timpanogotes, as Domingues and Veles de Escalante referred to them, were called fish eaters by other Indian groups (Jensen 1924:32). The Indians (the Timpanogotes) were said to have customs that resembled the western Shoshone and southern Paiute tribe (Steward, p. 40). Other authors maintain that the tribes found near the lake consisted of the Shoshone language group but were actually made up of Paiute, Goshiute, and Ute divi- sions. The Goshiutes were located in the area west and north of the lake, the Paiutes to the south and west of the lake, and the Ute tribes near the eastern side of the lake representing the Timpanogotes Indian tribe proper (Jen- nings 1960a:21). The importance of fish in the Indian life-style is brought out by the ref- erence by other Indians to them as fish eaters and by the fact that, before leaving Utah Val- ley, Dominguez's party purchased a large quantity of dried fish for supplies on their re- turn journey (Jensen 1924:23). Although it is impossible to reconstruct the use of the lake and rivers by the native population, it is evi- dent that the lake played a central role in the life of the people who resided near it prior to its occupancy by Anglos. Anglo Accounts of the Lake and Environs Dominguez and Velez de Escalante's ex- ploration and associated journal represents the earliest available recorded description of Utah Lake and its environs. Judging from their descriptions of the area, the Dominguez party was much more interested in the land around the lake than the lake proper. Since the Spaniards were interested in creating ag- ricultural settlements, the fertile, well- watered lake plains received the bulk of their attention. Dominguez described the lake and the area around it as follows: On the northern side of the San Buenaventura River, as we said before, there is a ridge of mountains, and from what we could see of it, it nuis from northeast to southwest more than seventy leagues. In its widest part it is more than forty leagues, and where we crossed it, perhaps thirty. In this ridge, on the western side, at 4()°49' latitude, northwest, a quarter north of the town of Santa Fe, is situated the Valley de Nuestra Senora de la Merced de los Timpanoautzis, surroimded by the highest peaks of the ridge from which four medium- sized rivers descend which irrigate the valley, flowing until they enter the lake which is in the center. The plain of the valley from southeast to northwest extends about sixteen Spanish leagues [one Spanish league equals 2.63 miles] and from northeast to southwest ten or twelve leagues. It is all clear land except for the marshes bv the side of the lake where the .soil is good for every kind of planting. Of the four rivers which irrigate the valley, the first one on the southern side is the Aguas Calientes River [Spanish Fork] in whose extensive valleys there is 1981 Utah Lake M ONOGRAPH 13 ifiound en()ui;li, easih' ini^att'tl, lor two lar^e towns. Tlu' second rivor, going nortli, tliii-e Ifugnes from the first one, is more abnndant and can support a large town or two smaller ones, there being much good soil, easily irrigated. This river, before emptying into the lake, is di- \ided into two branches. On its banks, in addition to the poplars, there are tall alder-trees. We named it the San Nicolas River [apparently Spring Creek and Hobble Creek]. Three leagues and a half northwest is the third river, of flat valleys with good soil for planting. It is more abundant than the two above mentioned; it has large poplar groves and valleys of good soil with suf- ficient water to support two or even three large towns. We spent September 24 and 25 by its bank and named it the San Antonio de Padua River [Prove River]. NVe did not reach the fourth river, though we could see its poplar groves. It is situated northwest of the San An- tonio River, and it has on this side much flat and seem- ingly good soil. They told us it has as much water as the others, and therefore, several settlements or villages could be established by it. We named it the Santa Ana River [American Fork River]. In addition to these rivers there are in the plain many springs of good water and several springs which issue from the mountains. Throughout the vallev there is much good pastine and in some places flax and hemp grow in such abundance that it seems as though they had been planted deliber- ately. The climate is also good here because after suffer- ing from the cold from the time we left the San Buena- ventura River, now, night and day, throughout the valley, we feel very warm. Besides these excellent natu- ral features, the surrounding mountains contain suf- ficient timber and firewood, many shelters, springs and pasture lands to raise cattle and horses. All this is true of the north, northeast, east, and southeast parts. On the south and southwest there are two other extensive val- leys, also with abundant pasture and sufficient water. Tlie lake extends to one of these valleys. It may be about six leagues wide and fifteen long and nms northwest. By means of a narrow opening, according to what they told us, it unites with others very much larger. The Tim- panogotzis Lake is teeming with several kinds of edible fish, in addition to geese, beaver, and other land and wa- ter animals, which we did not see. . . . With three fortresses and three towns inhabited by Spaniards in communication with the forts, the door will be opened to a new empire which can be explored and populated. The base where the principal objective of the enter- prise should be established is the valley and the borders of the Lake of the Timpanogos near one of the rivers which water the valley, becau.se this place is the most pleasant, beautifiil, and fertile in all of New Spain. It is large enough in itself to support a city with as large a poulation as that of Mexico City and its inhabitants can enjoy many conveniences because it contains every nec- essary thing for the sustenance of himian life. The lake and the rivers which empty into the lake abound in many kinds of choice fish; there are to be seen there very large white geese, many varieties of duck, and other kinds of beautifid birds never seen elsewhere; bea- vers, otters, seals, and other animals which seem to be ermines by the softness and the whiteness of their fiir. In the valleys of these rivers there is much uncultivated hemp and flax (Auerbach 1943). The description of Utah Lake by the Span- ish does not indicate whether the lake is clear or muddy or any of its other physical charac- teristics. Compared to the New IVIexico area from which they had traveled, the lake and its adjacent fertile plains with the numerous streams entering it must have indeed present- ed a highly favorable spot. The fact that the water entering the lake and the lake itself were fresh, and that it provided an abun- dance of fish, met, the purposes of the Span- ish. The land on the lake plains would be the center of any settlements they established and, therefore, descriptions of the lake were secondary. It should be noted, however, that Dominguez did indicate that settlers should include carpenters who could build boats for use in navigating the lake and further explor- ing it to discover its utility (Auerbach 1943). The Spanish under the direction of Domin- guez and Velez de Escalante never returned to Utah Valley, and further information con- cerning the lake and its environs was not written until fur trappers visited the area in the early 1800s. Recorded evidence seems to indicate that either William H. Ashley of the Rocky IVIountain Fur Company or Jedediah Smith were the first early fur trappers to visit the lake. William Ashley is reputed to have vis- ited the lake in 1825 (Bancroft 1889:21), but some scholars question whether he actually reached the Utah Valley area or whether the lake he visited was actually the Great Salt Lake (Dale 1918:155,168). Because of Ash- ley's purported visit to Utah Lake, the name Ashley Lake has occasionally been used in re- ferring to the lake (Dale 1918:187). If Ashley did in fact visit Utah Lake, he left no written account of it. At least one other fur trapper, Etienne Provost, visited Utah Lake in the pe- riod of 1824, and from him the Provo River and Provo City take their names (Jensen 1924:28-29). Daniel T. Potts, a trapper with Ashley's Rocky Mountain Fur Company from 1822 to 1827, recorded of Utah Valley, 'This is a most beautiful country. It is intersected by a number of transparent streams. The grass is at this time from six to twelve inches in height and in full bloom" (Frost 1960:62). Other trappers who visited the Utah Lake area left no written accounts on which to base an understanding of the lake and its characteristics. 14 Great Basin Naturalist Memoirs No. 5 John C. Fremont, a government explorer, visited Utah Valley in 1843 as his party re- turned from California. In addition, Fremont visited Utah Lake in another party in 1845. Fremont described the Utah Valley area as follows: In this cove of the mountains along its [Utah Lake] eastern shore, the lake is bordered by a plain where the soil is generally good, and in greater parts fertile; wa- tered by a delta of prettily timbered streams. This would be an excellent locality for stock farms; it is gen- erally covered with good bunch grass and would abun- dantly produce the ordinary grain (Fremont 1845:258). Fremont's account represents the last of the intermittent Anglo visitors to Utah Lake. Shortly after his visit, the Mormon pioneers entered the Salt Lake Valley and began per- manent colonization. Mormon Settlement and Use in the Utah Lake Plain Area The Mormon settlement of the Great Basin in 1847 represented the first permanent white occupation of the region around Utah Lake. The leader of the Mormon pioneers, Brigham Young, received his first report of Utah Lake while en route to the Salt Lake Valley in 1845 during an encounter with Jim Bridger. Brigham Young hoped that Utah Lake would provide sufficient fish to aug- ment the settlers' cattle (Wride 1961). After the arrival of the Mormons in the Salt Lake Valley and initial settlement of that area, an exploring party was sent to the Utah Lake area in December 1847. Under the direction of Parley P. Pratt, this small exploring group brought a wagon and boat into Utah Valley and attempted to fish on Utah Lake, then ex- plored the surrounding area. Pratt notes that, after traveling into Utah Valley, they arrived at . . . the foot of Utah Lake, a beautiful sheet of fresh wa- ter, some 36 miles long by 15 broad. Here we launched our boat and tried the net, probably the first boat and net ever used on this sheet of water in modern times. We sailed up and down the lake shore on its western side, but had only poor success in fishing. We, however, caught a few samples of mountain trout and other fish. After exploring the lake and the valley for a day or two, the company returned home, and a Brother Summers and myself stnick westward from the foot of the lake on horseback on an exploring tour (Jensen 1924:31). As a result of Pratt's favorable report of Utah Valley and continued population growth in the Salt Lake Valley, the Mormon leadership began plans for settling Utah Val- ley in late 1848. In March 1849 a group un- der the direction of John S. Higbee, who had previously visited the Utah Lake area with Parley P. Pratt, came into Utah Valley and settled on the Provo River slightly west of present-day Provo City. The fort which they constructed represents the first Anglo settle- ment on the shores of Utah Lake. Associated with this settlement was the cultivation of common agricultural crops, with related di- version of water from the Provo River (Jen- sen 1924:33-38). During the same year additional commu- nities were founded around the lake on Battle Creek (Pleasant Grove) and Lakeview. The following year an additional six communities were founded— American Fork, Lehi, Payson, Spanish Fork, Spring Lake, and Springville (Table 2). It should be noted that by 1851 there were settlements along all the streams entering Utah Lake, and by the 1860s essen- tially all the communities in the area had been founded. Population growth in the region was based on agriculture and did not increase rapidly until after the 1940s. Little is known of the views of Utah Lake by the early settlers other than their statement that it was a freshwater lake. Since the initial colonists and explorers were coming from the Salt Lake Valley, this was the most important factor when com- pared to the saline Great Salt Lake. Since the freshwater streams provided culinary water, the settlers were never seriously concerned about the relative quality of the water within the lake proper. Likely the lake itself was ap- proximately the same as at the present in terms of amount of sediment suspended in the water and associated turbidity (Brimhall and Merritt 1976). A report in the early 1900s indicated that the water was cloudy and opaque three to six inches below the sur- face, which is similar to its present condition (Huber 1972:57). Although the settlers re corded few impressions of the lake, Utah Lake and its associated streams were of para- mount importance to them. Mormon Use of Utah Lake and Associated Streams Fishing from Utah Lake and adjoining streams was one of the primary uses of the lake by the Mormon settlers. On 6 January 1981 Table 2. Settlement and popul Utah Lake Mono(;raph lUion ^lowtli of communities around Utah Lake. 15 Settlement 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 Alpine, 1851 (Mountainville) American Fork, 1850 (Lake City, McArthurville) Benjamin, 1860 Elberta, 1895 (Mount Nebo) Genola. 1935 Goshen, 1857 (Sodom, Sandtown, Mechanicsville) Highland Lakeshore Lakeview, 1849 Lehi, 1850 Linden, 1925 Mapleton Orem, 1920 Palmyra Payson, 1850 Pleasant Grove, 1849 (Battle Creek) Provo, 1849 (Fort Utah) Salem, 1856 (Pondtown) Santaquin, 1851 (Summit Creek) Spanish Fork, 1850 Spring Lake, 1850 Springville, 1850 (Hobble Creek) Vineyard 135 208 319 466 520 496 407 509 441 571 775 1047 695 1115 1299 1942 2732 2797 2763 3047 3333 5126 5373 7713 150 417 661 580 575 153 ,300 194 394 298 645 470 526 195 171 247 390 582 528 457 376 276 344 391 831 1058 1490 1907 2719 2964 .3078 584 534 .586 830 14.36 1788 21.35 26.36 2397 .3031 526 9.30 1775 1926 2460 1618 1682 619 674 706 278 151 1.38 321 ,325 314 380 424 669 616 525 426 459 277 270 482 528 523 400 460 446 2826 2733 3627 589 587 801 663 907 1175 1915 2914 8.351 262 236 .3045 3591 3998 1754 1941 3195 4377 4659 1150 1644 1516 1980 18394 25729 4237 4501 4772 5327 20.30 2384 .3432 51,59 6185 8925 10.303 14766 18071 28937 .36047 53131 180 .353 510 527 894 693 609 610 659 781 920 1081 158 602 715 769 889 915 976 1115 1297 1214 1183 1236 1015 1450 2.304 2214 27.35 .3464 40.36 3727 4167 52.30 157 93 232 188 252 ,300 4,53 495 1.357 1661 2312 2849 .3422 .3.356 .3010 3748 4796 6475 398 435 560 543 719 267 6472 7284 7913 8790 1849 a party of six men was sent to fish Utah Knecht 1964:29). After settlement of Provo Lake by Brigham Young, but they were un- in 1849, fishing became an important part of successful in obtaining quantities sufficient to the subsistence economy practiced by the set- justify continued fishing efforts (Crawley and tiers. Spawning fish in the lower Provo River 16 Great Basin Naturalist Memoirs No. 5 and adjacent areas of Utah Lake were caught and utihzed fresh, dried, or salted in barrels for later use (Huntington 1960). With the passage of time, increased fishing took place on the streams entering Utah Lake (Gardner 1913). Since it was the custom of the Indians in the area to fish the streams during the spawn- ing season of the lake fish, they found the presence of the Mormon settlers and their ex- tensive fish catch an unwelcome competition as early as 1853 (Armstrong 1855:203-209). In the spring of 1855, when the Indians ar- rived, the Indian agent noted that "the Utah Lake and Provo River at this season of the year abound in fish known as mountain trout, and it is for the pvirpose of fishing that so large a number of Utah tribes of Indians re- sort hither every spring." According to the Indian agent, the Indians attempted to take fish through trapping, using of bows and ar- rows, and catching them with their hands in die riffles, but were unable to do so because of the competition from Mormon settlers who were using nets and seines to catch fish. As a result of the high water and the settlers' efforts, the Indians felt they could not obtain sufficient fish for drying, and the Indian agent arranged for the settlers to catch fish for the Indians' use. "At the insistence of some of the chiefs, I requested one of the fishing companies to fish for them, which request the company immediately complied with, and after some days successful fishing, they loaded the packhorses of the Indians with large quantities of fish." (Commissioner of Indian Affairs 1855:202-203). By 1856 one group of settlers had begun a commercial fisheries establishment that caught fish for use in the Utah Valley and Salt Lake area throughout the year (Carter 1975:8). The lake continued to be an in- tensive source of fish for the settlers of Utah Valley in the period from 1856 to 1860 as regulations were promulgated by Provo City and other communities to regulate the fish- eries of both the lake and streams entering into it. An ordinance for control of fishing privileges passed at the Provo City Council meeting on 6 Augu.st 1853 is the earliest re- corded evidence of control of the fishing (Jensen 1924:83-84). By the late 1860s and early 1870s, how- ever, the number of commercial fishing groups declined and fishing activity began to decrease as a result of diverting water from the streams for irrigation and the associated loss of fish population. The fishing continued on Utah Lake and adjacent streams through time, as indicated in Table 3's brief outline of the fisheries of Utah Lake to 1904 (Carter 1975:8-16). Fishing and fishing activities on Utah Lake were as significant to the Mormon settlers of the valley as they had been to the American Indians previous to the Mormon settlement. The single most important use of Utah Lake and the streams associated with it was for water for irrigation purposes (Fig. 1). As each community was established, primitive diversions were made to carry irrigation wa- ter to adjacent fields. Two canals were devel- oped in Provo city in 1850 for irrigation of fields in the area of present downtown Provo. The first was the Turner ditch, which wa- tered approxiinately half a square mile, and sec- ond was the East Union ditch, which carried water to the foothills east of the present downtown area (Jensen 1924:63). As time passed, these systems were expanded and wa- ter was diverted higher up the stream to bring additional land under the ditch for irri- gating. By 1874 all the summer low flows in the streams had been appropriated and dis- putes began as to who actually controlled the rights to the waters that had been claimed or utilized. Some idea of the extent and rapidity of water diversion is evident from the fact that by 1869 one-third of the ditches and laterals found in Utah Valley in 1920 had been com- pleted (U.S. Bureau of Census 1920). Also by 1869 there were five major canals taking wa- ter from the Provo River. In addition, the so- called Highline Canal was under construc- tion; it followed the base of the mountains from Provo Canyon to the bench areas along the eastern bank of Provo River. At the same time American Fork River had four major canals taken from it, one to American Fork, one to Lehi, one to Pleasant Grove, and one to the area north of these communities. Dry Creek had canals taking water to the Lehi area and to the vicinity of present-day Al- pine; Hobble Creek had three canals divert- Utah Lake Mono(;haph 17 TAHi.h. 3. Uriel aniu Utah Lake, 1849-1900 d llisi, Beginning of commercial fishery in Prove River and Utah Lake. Activity 1890 Territorial game warden appointed. Largemouth bass introduced into Utah Lake. Spawning fish in rivers and streams still caught. Rapid increase in commercial fishing with year-round harvest, long seines in- troduced. Selling of fish common in Utah Valley and Salt Lake Valley. State, coun- tv, and local goverinnents begin some regulation of fishing. Provo City regulated the Provo River, while Utah County regu- lated fisheries of Utah lake and other streams (Spani.sh Fork, Jordan River, Pay- son Creek, and Provo Bay streams). Decline in the number of commercial fish- ing groups; consolidation of fishing areas. Jens Michelson begins long-term fishery, mouth of Spanish Fork River. The fishing decline was noticed and a spe- cial committee was appointed in 1870 at the general conference of the LDS Church to develop fish culture. Yarrow and Cope visited and felt the trout fishery had declined one-third. Several court cases on mesh size of seine and unli- censed fishermen. Continued decline in catch; still a ready market. Territorial legislature bans seining and poisons or explosives, and requires a fish passageway in all dams. First Utah County fish and game commis- sioner appointed. Entrances of all irrigation canals should be screened. Lawful to fish with seine 200 yards long by 12 feet wide, mesh 2 inches center and U/^ inches in wings. Mesh size reduced to l'/2 inches for 50 feet center. Screen law for irrigation ditches repealed because cleaning screens a nuisance. Carp introduced into Utah Lake. Season established from 1 October to 1 June to legally seine or hook and line fish for trout. 1890-94 1894 1895 1897 1897 1897 1899- 1904 Black bullheads, channel catfish in- troduced into Utah Lake. Most of trout shipped out of territory. Suit brought in Utah County court to halt practice. Largemouth bass become very conunon in Utah Lake. Only carp, clubs, mullets, and suckers can legally be taken by seine. Mills, factories, power plants, and manu- facturing concerns required to install fish screens in intake canals. Unlawful to seine within one-half mile of inflowing river into Utah Lake. Around 500,(XX) pounds of fish (mostly no trout) from Utah Lake shipped out of state. ing water to the Springville and Mapleton areas; and Spanish Fork River had five canals diverting water to irrigate much of the area in the central and southern portions of Utah Valley. In addition, canals of undetermined number also diverted water from Santaquin and Peteetneet Creeks by 1869 (Griffin 1965:41-43). Later, larger dams were con- structed farther upstream to divert water to higher areas around Utah Lake and/ or to store water. Figure 5 indicates the major irri- gation canals in the vicinity of Utah Lake at present. Of the four larger rivers that flow into Utah Lake, Provo River brings more than one-half the total water flow into Utah Val- ley. The natural flow of the Provo River at its entrance to Utah Valley averages approx- imately 358 X lO^mVyr (290,000 ac-ft/yr) (Hudson 1962:80). Man-made modifications to this flow include 14 small reservoirs on the headwaters of the Provo River, totaling 12.3 X lO^m^ (10,000 ac-ft) of storage constructed prior to 1910 and diversions from other drainage basins. The Weber-Provo Canal is the largest of the intrabasin transfers and brings water from the Weber River basin into 18 Great Basin Naturalist Memoirs No. 5 Major Distribution Cana Fig. 5. Major distribution canals in the vicinity of Utah Lake. 1981 Utah Lake Monograph 19 the Provo River drainage basin. The canal was originally built in the 1920s and was lat- er enlarged in 1947-1951 as part of the Deer Creek project. The annual amount delivered to the Provo River varies from 41 X 10^ to over 93 X 106m3 (33,000 to over 75,000 ac- ft), depending on the amount of precipitation in a given year (Hudson 1962:82-83). In ad- dition, water is transferred from the Utah Lake drainage basin to the Great Salt Lake drainage basin by means of the Salt Lake aqueduct, which takes between 26 X 10^ and 33 X 10«m3 (21,000 and 27,000 ac-ft) of wa- ter annually for use in Salt Lake Valley (Hud- son 1962:84). The most recent modification of flow in the Provo River was associated with the Deer Creek Reservoir, begun in 1938 and completed in 1941. The reservoir has a usable capacity of 189 X lO^m^ (153,000 ac-ft) (about one-half the average annual flow of the Provo River). The net sea- sonal effect on the Utah Lake area has been an increase of between 4.9 X 10^ and 7.4 X 106m3 (40,000 and 60,000 ac-ft) annually dur- ing the summer season (Hudson 1962:84-85). The Spanish Fork River basin occupies the southeastern portion of Utah Valley and av- erages about 123 X lO^mVyr (100,000 ac-ft) of flow imder natural conditions. Additional water is diverted from the Colorado drainage basin via the Strawberry Reservoir system completed in 1915. Water from Strawberry Reservoir is diverted into the Diamond Fork River, a tributary of the Spanish Fork River. The average amount of water diverted into the Spanish Fork drainage has been approx- imately 86 X lO^mVyr (70,000 ac-ft/yr), particularly during the months of June, July, and August (Hudson 1962:90-x3). The Cen- tral Utah Project of the Water and Power Resource Service (formerly the Bureau of Reclamation) completed enlargement of the Strawberry Reservoir in 1975, and additional water will be diverted in the future from the Colorado River Basin to the Great Basin via the Spanish Fork River. Irrigation reservoirs have also been con- strvicted on the headwaters of the Peteetneet Creek-Payson system, American Fork River, and other tributary streams entering Utah Lake. These reservoirs are much smaller than either Deer Creek or Strawberry and are used to regulate the flow of the streams for irrigation purposes. Through diverting water for irrigation, some of the streams entering Utah Lake are completely dry in late sum- mer. Use of water from Utah Lake proper for ir- rigation purposes is much less than that used from the streams entering the lake in Utah Valley. Historically attempts were made to utilize water from the lake for irrigation through use of pumping stations constructed on the west side of the lake where no per- ennial streams exist. One of the earliest of these projects was associated with the settle- ment of Mosida, which was developed on the southwest shore of Utah Lake by people from the Denver area from 1909 to 1917. This project consisted of pumping water from the lake with three pumps for irrigating 3845 ha (9500 ac) of land on the southeast shore of Utah Lake (Brough 1974:2-5). This was very successful initially as land was planted to or- chards and irrigated, but the lowering of the lake's water level as the wet cycle passed left the intakes of the pumps above water and the project was abandoned. There are several small irrigation companies presently taking water from a pumping plant on the northeast shore to irrigate a small quantity of land. One of the major factors affecting Utah Lake water is the "compromise" level of the lake. Irrigation interests in Salt Lake Valley wanted to use Utah Lake for storage of water for release to Salt Lake Valley in the late summer, but farms around Utah Lake be- came flooded with increased lake level. The first plan to raise the level of Utah Lake was in 1864, when it was proposed that a dam be placed at the head of the Jordan River to raise the level of Utah Lake four feet. The Provo City council objected to this action and the dam was not built (Jensen 1924:253-254). However, in the spring of 1879 the farmers of Salt Lake County began to build the proposed dam. By 1881 it was noted that high water in Utah Lake resulting from the completed dam was causing "fearful damage" to farms around the lake. Some farmers felt the best plan was to blow up the dam, but it was finally determined that the question would be submitted for arbitration between the two groups. In 1884 an agree- ment was reached that regulated the extent to which Salt Lake irrigation companies 20 Great Basin Naturalist Memoirs No. 5 could increase the level of the water in Utah Lake. The 1884 decision called for a 6-foot- wide opening in the bottom of said dam not to exceed 6 inches above the base of the ex- isting dam, which represented the low water- mark for the lake. Obstructions or diversions placed in this opening could not exceed 3 feet 3V2 inches. The level of the lake when it was raised 3 feet 3^2 inches was referred to as the compromise level (Jensen 1924:256-257). The difficulty of enforcing this agreement and the differing interpretations of where the low watermark was with reference to the compromise level resulted in additional suits. In 1895 additional adjudication was under- taken, and a new compromise level was reached 2 inches below the former one. This compromise level of 4,488.9 feet above sea level (later determined to be 4,489.34 feet) has been the shoreline since. It should be noted, however, that the actual shoreline fluctuates considerably because the opening in the dam at the head of the Jordan River during some spring high-flow periods will not allow tlie water to flow out rapidly enough to prevent an increase above this level— with resultant flooding of farm lands (Figure 6 shows lake fluctuation from 1920 to 1977). Utah Lake continues to be a storage area for Salt Lake Valley irrigation, and the streams flowing into it remain a primary source of irrigation water for the lands around the lake. As of 1979, recent expansion of the Strawberry Reservoir with future in- creased flow in the Spanish Fork River dur- ing the summer, and proposals for a new res- ervoir in the Provo River drainage basin above Heber (Jordanelle Reservoir) will fur- ther affect the flow of the Provo River. The Bonneville unit of the Central Utah Project, of which the foregoing changes are a part, in- cludes diking of the Provo Bay and Goshen Bay to further change the configuration and area of the lake proper (Central Utah Proj- ect, Bonneville Unit 1972). Other than for irrigation and fishing, the use of Utah Lake and its streams has been varied. Water from the rivers has been and is used for culinary purposes, including an aver- age of 31 X lOemVyr (25,000 ac-ft/yr) for use in Salt Lake City through the Salt Lake aqueduct, the use of springs in Provo Canvon for Provo City, and use of the headwater source areas of the Peteetneet and Summit Creek areas for their respective communities. These uses are minor when compared to the total volume of water involved in irrigation, however. The lake has historically been useful for other purposes. There was barge traffic on Utah Lake Historical Levels 1920 to 1976 . A^^^ ^ '^ ^\\^\^Xr.^^ .. ^ . . ^A.X'^'\> ^^^\ A/^ H^^^ A?^ A. ,^^^^^\/Va A^\. ^ " /.^A^^^^A-^'^''^ ■:: ^ '^\Ar v^^ 1 5! ■■■■ ' .— 1 .... 1 .... 1 .— 1 ■-. 1 ■— 1 ,... ' ,..- 1 ,___ 1 _,_ : Fig. 6. Water levels in LUah Lake. 1981 Utah Lake Monocjhafh 21 0 12 3 scola in mi CyA mericon Fork OPI»°*o"* Gro> Saratoga^ Rocky Beach Marina4 /American Fork Resort ^Woodbury Pork ►Gen eva Utah >na (Taylor OPfo*° Resort) ^TOId Lake Resort Lake 1 Jepperson's Boat VyS^.X^ ^ House ^ /■s_,-j1^ 1^— » l\ J Chessman i^ \Loy Resort V S^ ..^"'''^ Knudsen'sV / \^ Resort \ / / V \ \ V \ Spanish V Fork ) \ OSolem 1 Op ay son Fig. 7. Location of current and historical recreational facilities on Utah Lake. 22 Great Basin Naturalist Memoirs Table 4. Resorts on Utah Lake from 1860 to the late 1930s No. 5 Saratoga Walker-Chessman Woodbury Park Old Lake Resort Geneva Lincoln Beach American Fork Resort Mindock Resort Jepperson's Boat House Knudsens' Resort Lov Resort 1860s to present Baths, swimming pools, pavilions for dancing, picnicking 1870s-early 1900s Hotel, restaurant, boat rental 1880-1888 1883-1907 1888-1935 1889-ca. 1900 1892-1930S 1894-ca. 1900 1890S-1920 1913-ca. 1918 1913-1925 Provona (Taylor Resort) 1825-1930s Siunmer cottage, bath houses, dance pavilion, boat dock Pavilion, boat house, ice house, restaurant, bath house, two piers Hotel, saloon, bath houses, pavilion, boat harbor Tourist house, swimming pool, store, saloon, dance pavilion Dance hall, pool hall, piers, picnic facilities, cafe, bath houses Dance pavilion, picnic facilities, bath houses Picnic facilities, piers, boat harbor, boat yard, refreshment stands Boat rentals, fishing equipment rental, picnic facilities Boat rentals, picnic tables, bathing facilities Store, dance hall, 30 cabins, bath houses, picnic facilities Source: Glen R. Huber, "The Attitude of the People of Utah County Towards Utah Lake as a Recreational Site," Thesis, BYU, 1972, p. 27-35. the lake between Provo and Mosida during the period of the town's existence from 1909-1917 (Brough 1974:8). Eadier proposals had suggested that towns on the south end of Utah Lake could be connected directly with Salt Lake City via a canal down the Jordan River and Utah Lake, but by 1863 these plans had been abandoned (Steele, p. 21). There were other schemes for using Utah Lake for transportation that were never implemented, except for one which would have connected the rich mining area of Tintic with Provo through use of a boat entitled the "Flor- ence." Passengers and cargo were to be shut- tled between the Tintic stage lines on the west side of the lake and the Denver and Rio Grande western railway at Provo. The boat made one trip in 1891 to meet the stagecoach but failed to make connections. The idea was abandoned before a successful commercial link could be completed. Other uses of the lake for boating were primarily of an excursion nature and consisted of boats for carrying people about the lake for sight- seeing and dancing (Jensen 1924:267-268). One of the major uses of Utah Lake has been for recreation. The Anglo settlers rank- ed recreation as the lake's third most impor- tant use. Figure 7 indicates the location of 15 resorts that have existed around the shore of the lake (Huber 1972:29). Table 4 provides information on the specific resorts that have been located around the lake. Subsequent to the time of the resorts the most important de- velopments have been a.ssociated with the Provo boat harbor. The U.S. government as- sisted the city in its initial development in the early 1930s. It was maintained by Provo City and the Provo Boat Club until 1976, when it was turned over to the state. Since that time the boat harbor has been improved and now has facilities for camping, boating, and ice-skating. In addition, there are other private boat marinas around the lake, includ- ing the Rocky Beach Marina on the west side of the lake now utilized by a private boat club. The potential for future development as a recreation and aesthetic resource is great. There is potential for enlarged sport as well as commercial fishing. The increasing popu- lation of the Utah Valley area means that it will continue to be a major recreational site. Proposals by the Department of the Interior for diking the lake will increase recreation opportunities, as well as provide additional irrigation water for the lands around the lake. Utah Lake and its tributary streams were central to successful occupancy of the Utah 1981 Utah Lake M()no(;raph 23 Valley region by white settlers as well as to earlier Indian occupants. For the foreseeable future, Utah Lake will continue to be of cen- tral importance to Utah Valley residents. An understanding of its fauna and flora, geology, setting, and use is es.sential in understanding its importance and maximizing its use. Literature Cited Armstrong, G. W. 1855. Pages 20.3-209 in Report of the commissioner of Indian affairs. Washington, D.C. June 1855. .\sHCROFT, G. L., AND W. J. Derksen. 1963. Freezing temperature probabilities in Utah. Utah Agric. Expt. Sta. Bull. 489. 56 pp. .•\uERBACH, H. S. 1943. Father Escalante's journal. Utah Historical Quarterly 11:27-113. Bancroft, H. H. 1889. History of Utah. The Hi.story Company, San Francisco. 808 pp. BissELL, H. J. 1968. Bonneville— an ice age lake. Brig- ham Young Univ. Geology Studies 15(4):3, 65. Brimhall, VV. H. 1972. Recent history of Utah Lake as reflected in its sediments: a preliminary report. Brigham Young Univ. Geologv Studies 19(2):121-126. Brimhall, W. H. and L. B. Merritt. 1976. The geology of Utah Lake. Unpublished paper, Eyring Re- search Institute, Provo, Utah. 46 pp. Brough, C. 1974. Mosida, Utah. Press Publishing Com- pany, Provo, Utah. 70 pp. Bureau of Reclamation, U.S. Department of the Lnterior. 1972. Central Utah Project, Bonneville Unit Draft Environmental Statement. Salt Lake City. 579 pp. Carter, D. R., and D. \. White. 1975. A history of the fish and fisheries of Utah Lake with limnological notes. Unpublished paper, Brigham Young Univ. July 1975. CoFFMAN, W. E. 1944. The geography of the Utah Val- ley crescent. Unpublished dissertation, Ohio State Univ. 342 pp. Crawley, P. L., and W. Knecht. 1964. History of Brig- ham Young. Mascal Associates, Berkelev, Califor- nia. 407 pp. Dale, H. C. 1918. Ashley-Smith explorations. Clark Publishing Co., Cleveland, Ohio. .360 pp. Fisher, K. D. 1974. \ cartographic studv of Lake Bon- neville. Unpublished thesis, Brigham Yoimg Univ. 44 pp. Fourteenth U.S. Census. 1923. U.S. Department of Commerce, Bureau of Census, Washington, D.C. Compendivim. Fremo.nt, J. C. 1845. Report of the explorer expedition to the Rocky Mountains in the years 1842 and to Oregon and North California in the vears 1843-1844. Gates and Seaton, Wa.shington, D.C. 693 pp. Frost, D. M. 1960. Notes on General Ashley. Bane Ga- zette, Barre, Massachu.setts. 159 pp. Gardner. H. 1913. Historv of Lehi. Deseret News Press, Salt Lake City, Utah. 463 pp. Griffin, R. D. 1965. The Wasatch Front in 1869: a ge- ographic description. Unpubli.shed thesis, Brig- ham Young Univ. 115 pp. HiNTZE, L. F. 1973. Geologic history of Utah. Brigham Young Univ. Geology Studies 20(3): 181. HuBER, G. R. 1972. The attitude of the people of Utah County towards Utah Lake as a recreation site. Unpublished thesis, Brigham Young Univ. 214 pp. Hudson, J. 1962. Irrigation water use in Utah Vallev, Utah. University of Chicago Research Paper 29, Chicago. 249 pp. Huff, N. 1947. Memories that live. Art Citv Publishing, Springville, Utah. 488 pp. Huntington, O. B. 1942. Diary. Unpublished manu- script, Brigham Young Univ. Library 1:169, 2:455. Irving, W. 1961. The adventures of Captain Bonneville U.S.A. Univ. Oklahoma Press. 297 pp. Jennings, J. D. 1960a. The aboriginal peoples. Utah His- torical Quarterly 28(3):21 1-222. 1960b. Early man in Utah. Utah Historical Quar- terly 28(1 ):.3-27. Jensen, J. M. 1924. History of Provo, Utah. New Cen- tury Press, Provo, Utah. 414 pp. Jensen, J. R. 1972. A thematic atlas of Utah Lake. Un- published thesis, Brigham Young Univ. 72 pp. MoNTiLLO, E. D. 1968. A study of prehistoric settlement patterns of the Provo area in central Utah. Lln- published thesis, Brigham Young Univ. 101 pp. Steele, R. D. (No date). Goshen Valley history. Pub- lished privately, Goshen, Utah. 266 pp. Stevens, D. J., ed. 1972. Physical geography of Lake Bonneville. Selected papers, Brigham Young Univ. 59 pp. Steward, J. H. (No date). .'Kboriginal and historic groups of the Ute Indians of Lltah: an analysis (mim- eographed). 104 pp. Swenson, J. L. 1972. Soil survey of Utah County central part. U.S. Department of .Agriculture, Soil Con- servation Service, Washington, D.C. 161 pp. U.S. Department of the Interior, Office of Indian Affairs. 1855. Pages 202-203 in Annual report of the commissioner of Indian Affairs. Washington, D.C, A. O. P. Nicholson. Utah Climatological Data. 1950-1975. National Oce- anic and .Atmospheric Administration, National Climatic Center, .\sherville. North Carolina. Wormington, H. 1955. A reappraisal of the Fremont Culture. Proc. Denver Mus. Nat. Hist. 1:200. Wride, C. 1961. The agricultural geography of Utah County. Unpublished thesis, Brigham Y'oung Univ. 164 pp. GEOLOGY OF UTAH LAKE: IMPLICATIONS FOR RESOURGE MANAGEMENT Willis H. Brimhall' and Lavere B. Merritt^ .\bstract.— Utah Lake is a remnant of Lake Bonneville, from which it originated about 8,000 years ago. Analysis of sediment cores reveals significant variations in lake salinity and sedimentation rates. Notable examples are a very dry, high-salinity period between 5000 and 6000 vears ago; a major freshening, wet period between 2700 and 3000 years ago; and a very drv, high-salinitv period between 1400 and 2600 vears ago. smaller variations are interspersed through the lake's history. Long-term sedimentation rates are estimated at about 1 mm (0.039 in) per year in most of the lake, but post- colonization rates appear to be about 2 mm (0.079 in) per year. Faults in the lake appear to be lowering the lake bottom at about the same rate as sediment has been filling it. Bottom sediments consist of about 60 to 80 percent calcite in the lake proper, much of which precipitates from the lake water itself. The lake-bed faults are similar in character to those of the Wasatch Fault that bound the valley and mountains a few miles to the east. Lake bottom springs and seeds are localized, in the most part, along the eastern and northern lake margins where all major tributaries occur and groundwater recharge is largest. Only limited spring activity appears to be associated with the faults. In a geological .sense, Utah is an old lake— .shallow, turbid, and slightly saline— and has been since its '"birth" with the demise of Lake Bonneville approximately 8,000 years ago. Geologic History and Setting OF Utah Lake Utah Valley, of which Utah Lake occupies more than one-fourth, lies near the junction of three of the great physiographic provinces of North America. To the west stretches the Great Basin, a vast expanse of arid inter- montane valleys extending from the Wasatch Mountains to the Sierra Nevadas. To the east lies the western portion of the Rocky Moun- tains, expressed in central Utah by the high peaks of the Wasatch Mountains rising above the Wasatch Fault, one of the largest of the fractures of the earth's cmst in North Ameri- ca. Not far away to the .southeast is the color- ful Colorado Plateau Province. The rich and varied physiographic setting of the valley and its lake .suggests that they are heirs of a rich and varied natural history, the principal part of which, for present purposes, is that associ- ated with the past 30,000 years. Utah Valley and its companions in the Great Basin were born in the aftermath of convulsions that seized the crust in central Utah some 70 million years ago as North America moved westward and collided with the lithosphere of the western Pacific Ocean. Huge sheets of .sedimentary rock, crumpled in paroxysm, formed the ancestral Rocky Mountains of the region. Later, some 30 mil- lion vears ago, the cmmpled rocks began to be blocked into intermontane valleys by high-angle faults, one of the most famous of which is the Wasatch Fault that bounds Utah Valley on the east (Fig. 1). Recurrent move- ments on these faults continue to the present time, and thus maintain the intermontane ba- sins in spite of erosion and infilling of .sedi- ments from the highlands. The high-angle faults are the principal structures contributing to the intermontane physiography. Rock waste eroded from the rising mountains has been transported down- ward and deposited in the valleys. Probably sediment as thick as several thousand feet oc- cupies the central portions of Utah Valley (Cook and Berg 1961); similar thicknesses of rock have been worn away from the ever- rising mountains. A dynamic equilibrium .seems to have been maintained for some 30 million years between the uplifting of the 'Department of Geology, Brighain Ycmni; diversity, Provo, I'tah H4H02. ■Department of Civil Engineering, Brighani Young University, Provo, L'tah 84602 24 1981 Utah Lake Monograph 25 and west of Utah Lake are composed of bedrock rang.ng f-m Tertia.v to Preca.nbr.an age. The Wasatch marks the boundary between the two domains (modified from Stokes 19bi.). mountains and the downdropping of the val- ley on the one hand, and of erosion and infilling on the other. Lake Bonneville (Fig. 2), the ancestor of Utah Lake and the Great Salt Lake, occupied the intermontane basins to a greater or lesser 26 Great Basin Naturalist Memoirs No. 5 Red Rock Pass Quaternary (^ Glaciers UINTA MOUNTAINS Lake Bonnevill Maximum Fig. 2. The distribution of Lake Bonneville at its inaximuni size (adapted from Bissell 1968). extent from about 75,000 years ago to about 8,000 years ago (Gilbert 1889, Bissell 1968). Lake Bonneville coincided in time with the Wisconsin stage of the Pleistocene Epoch; that is, with the last stage of the Great Ice Age that has so profoundly affected planet earth during the past one million years or so. The size and depth of Lake Bonneville is recorded in the layers of sediments accumu- lated on its margins and floor. The lake was largest during times of cool, wet climates, smallest in times of warm, dry climates (Bis- sell 1968). The level and extent of the lake fluctuated through three principal levels, des- ignated the Alpine, Bonneville, and Provo substages (Fig. 3). At its highest level, some 30,000 years ago. Lake Bonneville spilled over into the Snake River drainage at Red 1981 Utah Lake Monograph 27 Altitude (Feel) 5200 - 5100 - Approxlmately 5150-5200 ft. Approximately A /J Second Spillover 5100 ft / l//V>^-5l35ft. r\ /~\ r\ / Bonneville / \ \ / ^^"""^ 5000- 1 \j \ / 1 4900 - / So/I upon 1 1 \ / subaerial sediment 1 / \ 4800- 4700- / ALPINE \ \ \ 4800 ft / SUBSTAGE \ r~^^ X ^''lyV^T'' / / /LEVEL No. n 4750ft. \ {BONNEVILLE \ /Na\ 1 / SUBSTAGE / 1 / 2 1 4600- 45 00- 4400- 4600 ft. \ / 4600 ft 1 Soil upon \ / PROVO \ "stANSBURY" UTAH subaerial sediment \J Ql IRCiTAfiF \ LEVEL LAKE 4500 ft ^Utf^fAUt 1 4490f, 4480 ft. Soil upon A /~ subaerial sediment \ / "Altittiermaiy Danger Cave \ j 4300- '"°"l43oo/\y „ Lake^ / Wendover \J H.J. Bissell- 1969 Fig. 3. Elevations associated with the principal substages and lesser fluctuations of Lake Bonneville. Lake Bonne- ville dried up and passed from existence at the end of the Wisconsin Stage, some 10,000 years ago. Utah Lake origi- nated in the aftermath of Bonneville's passing and is associated with the Holocene Epoch, 10,000 years ago to the present (adapted from Bissell 1968). Rock Pass near Preston, Idaho (Fig. 2), and quickly dropped from about 1585 m (5200 ft) above sea level to about 1463 m (4800 ft), where the lake stabilized at the Provo sub- stage, with fluctuations, until about 8,000 years ago. The relatively long period of Lake Bonne- ville's stability at the Provo substage led to the formation of some prominent benchlands, such as those at Orem, Mapleton, and Span- ish Fork. These alluvial benchlands, formed where the rushing rivers met the lake, are among the most striking topographic features of Utah Valley. The climates of North America generally became warmer and drier at the end of the Pleistocene (Great Ice Age) Epoch some 10,000 to 12,000 years ago. Ice sheets for- merly occupying much of the northern por- tions of the continent began to retreat. In the Great Basin, Lake Bonneville passed from ex- istence, and in the aftermath the Great Salt Lake and Utah Lake were formed. Utah Lake, born and orphaned of Lake Bonneville, records its nearly 10,000 years of history in its sediments. Hansen (1934) was first to recognize that variations of sand, silt, clay, and plant remains, including wood, ex- posed in a test pit northwest of the mouth of Provo River, associate with strong changes of the level of the lake and of changes of cli- mate in the region during the past few hun- dred to thousands of years. Hansen did not assign ages to the variations; the carbon 14 dating method was not available at the time. Bolland (1974) collected a core sample, 500 cm (197 in) deep, at a point about 2.5 km (1.6 miles) west of Geneva in the late summer 28 Great Basin Naturalist Memoirs No. 5 0- Core , , . , , . . . , 1 , , . , 1 , , , . 1 , . 10 20 ^ ■ 1 ■ ■ ■ ■ 1 30 V Present Lake Level 50- ? ^ 100- 2 \ '-P ^ 150- < ( Low O 300- 7~^ c 350 o 2 3 400- O ^ > ^_s 450- 1 . . . , 1 4000 o Percent Calcium Lake Level Low High Fig. 4. Characteristics of a core sample of Utah Lake sediments collected approximately 2.5 km west of Geneva. High concentrations of calcium (calcite) are believed to associate with low levels of the lake as compared to recent levels. The sand and peat layers below 450 cm are believed to correlate with the altithermal. a time of extreme aridity described by Antevs (1948) (adapted fi-om Brimhall 1973). of 1970, to study the presettlement history of Utah Lake by means of sediment changes and variations in fossil diatoms. The core (Fig. 4) consisted of nearly uniform gray silt to a depth of 450 cm (175 in). Below that depth, to 510 cm (201 in), the core consisted of fine quartz .sand with a small layer of peat at 490 cm (193 in). The change from silt to sand and to peat clearly indicates that at some time in the distant past, Utah Lake was much lower and .smaller than at present, since the sand and peat must associate with an ancient shoreline that persisted over a considerable period of time. Bolland submitted a sample of the peat, weighing 1.8 grams (0.004 lb.), to Radiocarbon Ltd., Spring Vallev, New York, for dating. The result was 11,400 ± 800 years. Brimhall (1973) performed a chemical analysis of the major constituents of the core and assigned some time lines based on appar- ent inputs of iron from the steel plant, phos- phorous from sewage, and other criteria, but evidence obtained during the summer of 1975 (Brimhall, Ba.s,sett, and Mcrritt 1976) make these data appear to be in error. We believe that the 11,400 ± 800-year-old dat- ing of the peat layer is at least twice too large. Contamination of the sample with small amounts of detrital calcite could cau.se the result to be too high. Based on data from the latter study, and reassignment of time lines in the core, it is presently believed that the sand layer at the bottom of the core correlates with a verv drv period recognized in the Great Basin .some 4,000 years ago (Antevs 1948). The begin- nings of Utah Lake are believed to as.sociate with sediments about 4 m deeper than the bottom of the core sample, as shown in the acoustical profile (Fig. 5). If this assignment is correct, as we believe, then approximately 8.5 m (28 feet) of sediment have accumulated since the beginning of Utah Lake. The aver- age rate of accumulation of .sediment is ap- proximately 8.5 m (28 ft) in 10,000 years, or 0.00085 m (0.033 in) per year. Some ques- tions still remain, however, as to the lake's sedimentation rate, and this value should still be regarded as tentative. 1981 Utah Lake Monograph 29 (r. UJ H UJ 2 10 << ~^.- ^-Vr"^'^:>;'^:5 5;?;^! SS^fSt. ^?-i^l-i^t*r5;'S? :. i;-:-.;-."?: '-S^r* ? c^^^S- j^f. -1^ 100 DISTANCE, METERS 200 Fig. 5. Acoustical profile of sediments in the vicinity of the sample collected and analyzed by Holland (1974) and Brimhall (1973). The reflection at about 4 m is believed to correlate with the .sandy layer (si) described by the above workers, and the second, stronger reflection at about 8.8 m is believed to correlate with the clay unit (cu) of the Provo Formation, deposited in the waning stages of Lake Bonneville. Assuming a linear rate of deposition, the .sand layer with its contained peat was depos- ited from 5300 to 6000 years ago during a long, dry period called the "altithermal" by Antevs (1948). Variations of the calcium content of the cores between 18 and 32 percent (Fig. 4) are believed to associate with fluctuations of lake level caused by short-term wet and dry cycles of several years' duration, not as long as those associated with the sandy and peat layers. Rises in calcium content associate with de- creased inflow during dry periods and con- tained large evaporation loss from the lake surface. An increased concentration of salts in the lake, including calcium and carbonate, and subsequent increased precipitation of calcite (calcium carbonate) occurs. Under natural conditions, lake level could vary at least 2 m (7 ft) since the flow rate in the out- flowing Jordan River is a function of lake lev- el. The lake level is a function of inflow, out- flow, and evaporation over time. Inspection of the calcium profile (Fig. 4) reveals some pronounced variations of con- centration in the upper half of the core. Un- usually high concentrations occur between 120 and 220 cm (47 and 87 in), and unusually low concentrations are present between 230 and 250 cm (90 and 98 in). Assuming that the high concentrations correlate with low lake level and size, and the low concentrations with high lake level and size, and assuming an average sedimentation rate of 0.85 mm/yr (0.033 in/yr), then the lake was small and shallow between 1400 and 2600 years ago, and larger and deeper between 2700 and 3000 years ago. The profile also reveals that the level of the lake has fluctuated to a lesser extent than the above extremes during the past 1000 years. The sharp peak at about 25 cm (9.8 in) is believed to as.sociate with a very dry peri- od in the southwestern U.S. some years ago, based on tree ring data (Schulman 1956). It should be noted, however, that the upper 10 30 Great Basin Naturalist Memoirs No. 5 cm (3.9 inches) of the core sample was im- perfectly obtained since the sediment-water interface was not sharply defined. Reports have been made commonly in the news media in recent years that Utah Lake was a clear, blue lake in precolonization times, but the geological aspects of the lake as reflected in its sediments make the claim seem doubtful. Most of the reports by early settlers of the pristine quality of Utah Lake associate with diary accounts in which ob- servers viewed Utah Lake from such distant points as Point-of-the-Mountain, or from nearshore localities where rivers emptied into the lake. Under these conditions, it is under- standable that observers would conclude that the lake was clear. But the sediments in the lake, most of which were accumulated well before the coming of man into the valley, re- cord that the lake has been a geologically old lake for a long time, stretching back to Lake Bonneville, and perhaps beyond. It is be- lieved that geological factors are still the controlling factors in the lake, although hu- man interaction and impact on the lake are important locally, particularly along the east- em shoreline. Although Utah Lake has existed less than 10,000 years, a relatively short time in the span of geologic time, it is nevertheless an old lake from a geological point of view. The chief characteristic contributing to its senes- cence is its shallowness. At present, its aver- age depth is about 2.8 m (9.2 ft) (Fig. 6), which contributes greatly to its turbidity, large evaporation losses, hence slightly saline waters, and warm summer temperatures, hence abundant commimities of algae. In summary, the geological setting and his- tory of Utah Lake is rich and varied. The lake lies in one of the most scenic regions of North America. Climatic changes occurring in the region over the past 75,000 years, and especially the past 10,000 years, have been spectacular, for they range from very wet to very dry, and the record of these changes is preserved in the sediments of the lake as well as in other natural systems such as tree ring growth. It is clear that these prehistoric changes occurred essentially independent of the in- fluence of man. Natural forces still appear to dominate the lake as a whole although some man-caused influences are locally important. The potential exists, under the influence of continuing growth of populations in the sur- roundings, for man-made influences to domi- nate. Whatever the outcome in the future, the geological history of Utah Lake will con- tinue to give a useful perspective on the management of the lake and its resources. Sediment Character and Trends in Utah Lake Previous Work.— Bissell (1942) published a preliminarey report on the character of the sediments in Utah Lake. Sonerholm (1973) has described the broad outlines of the min- eral compositions of the sediments of the lake and their distribution. Bingham (1975) has described the major trends of the particle sizes contained in the sediments and their dis- tribution through the lake. Brimhall (1973) has studied the character of sediment in a core sample, 520 cm deep, to determine the broad outlines of the Holocene (recent) geo- logic history of the lake; and Brimhall et al. (1973) conducted a reconnaissance study of the sediments of Utah Lake, Holocene to up- per Pleistocene age, by means of an acoustic- al profiler. The latter investigation yielded significant information, heretofore imavail- able, on the character and distribution of deep-water springs and of the geologic faults in the lake floor, both of which are important to resource management. Sedi7nent Types.— Utah Lake is character- ized as a carbonate-type lake because the principal constituent of its sediment is cal- cium carbonate, CaCOg, whose mineral name is calcite. The compound as found in the lake is not pure, but carries small concentrations of magnesium, strontium, and other impu- rities. Quartz and other forms of silica are generally the next most abundant con- stituents, followed by clay minerals of the il- lite and montmorillonite and mixed layer types. Locally, near the mouths of the major riv- ers joining the lake and near the existing shorelines where wave action is vigorous, quartz is concentrated in long, narrow rib- bons of sand. The shallowness of the lake intensifies the interaction of the water with sediment. Dur- ing heavy storms the waves generated on the 1981 Utah Lake Monograph 31 Fig. 6. Elevation contours of the floor of Utah Lake. The contours are given in feet below the level of the lake surface at 1367.94 in (4488 ft). Add 1.34 ft to the depths to reference them to compromise elevation (4489.34 ft) (adapted from Sonerholm 1973). lake have sufficient amplitude to stir much of imparts the impression of pollution, although the lake floor, which contributes to the this turbidity results from a natural process, strong turbidity of the water, which in turn The sediment-water interface on the lake 32 Great Basin Naturalist Memoirs No. 5 floor is not generally sharply defined, but is gradational. Core samples collected during the summer of 1975 indicate that the transi- tion zone from water to sediment is usually about 0.5 m (1.6 ft). The consistency of the sediment in the transition zone ranges from thin to thick soup. The upper margins of these sediments are frequently stirred by storms and by bottom-dwelling organisms. This is a leading factor in the turbidity (qual- ity) of the water; and the condition is due, in the main, to natural rather than man-caused processes. Based on the character of sediment core samples and the configuration of the valley floor, it appears that this condition has existed throughout the life of the lake. Distribution of Calcium Carbonate.— So- nerholm (1973) collected 140 samples of bot- tom sediment from localities spaced on a one-mile grid and analyzed them chemically to determine the composition of individual samples and the distribution of the elements throughout the lake. From these data, he de- termined the mineral constituents and trends for the lake as a whole. The contour map of calcite content ratio shown in Figure 7 is a statistical trend surface map that shows only the broad patterns present in the data. Throughout most of the lake calciimi car- bonate exceeds 60 percent (dry weight) of the sediment. In two principal areas, the concen- tration exceeds 70 percent. The first and larg- est of these extends from the middle of the lake opposite Provo Boat Harbor to the west- ern midportion of Goshen Bay. The second and smaller area lies in the northwestern por- tion of the lake between Pelican Point and Saratoga Springs. The pattern observed is easy to explain. Calcium is transported to the lake by surface waters and by subsurface wa- ters. The valley and mountains surrounding the lake, and the sediment and bedrock be- neath the lake are composed in the main of limestones and, to a large extent, sandstones, or combinations. Most of the calcium arrives in solution, but some arrives as particulate matter suspended in surface waters. Calcite is precipitated from lake water as evaporation increases the calcium and carbonate concen- trations and by calcite depositing algae and other microorganisms abundantly present in the interior of the lake. The particles thus formed are tiny, ranging in the silt and clav size (from less than Vs mm to submicroscopic dimension). Such particles are too small to settle readily in the nearshore regions where wave action is vigorous. Consequently, they accumulate more in the central parts of the lake. The unusually high concentration of cal- cite in the northwestern portion of the lake associates with thermal springs, striking faults (see later section of this paper), and with an unusually large concentration of organic mat- ter in the sediments, presumably derived from higher biological activity in the area (Bingham 1975). Distribution of Silica.— Silica, as used in this report, means any of the several forms of silicon dioxide present in the lake sediments. These may include quartz, SiO,, or hydrated and/or amorphous forms of variable compo- sition that may be associated with organisms such as diatoms that gather silica from water and sediment to form their shells. Inasmuch as calcium carbonate generally exceeds 60 percent of the sediment, and silica comprises most of the remainder, the distri- bution of silica shows an inverse pattern to that of calcium carbonate; in short, the car- bonate dilutes the silica. Silica ranges from near 50 percent of the dry weight of sedi- ment in the nearshore regions to less than 15 percent in the regions occupied by high car- bonate concentrations. Again, the pattern is not difficult to explain. Quartz is a hard, du- rable mineral, as are the other forms of silica, when compared to calcium carbonate. More- over, the individual grain sizes tend to be larger than those associated with carbonate. These two factors, plus the input of quartz in sediment from the major rivers and wave ac- tion near shore, tends to deposit the silica in the near shore portions of the lake. Distribution of Clai/ Minerals.— The term clay is used commonly in two different mean- ings, both of which are used in literature bearing on this report, so a clarification must be made as to the meaning of the term. Clay on the one hand refers to any natural in- organic substance whose constituent particles are less than 1/256 mm in size. Clay on the other hand refers to any of a family of min- eral aluminosilicates whose constituent ele- ments are structured in sheets and whose in- dividual particulates are typically less than 1981 Utah Lake MoNO{;RAPn 33 o oT () Fig. 7. Sixth degree trend surface map of calcite concentrations in Utah Lake sediments. Contours are in weight percent, dry sediment (adapted from SonerhohTi 1973). 34 Great Basin Naturalist Memoirs No. 5 1/256 mm in size. In this paper, the term clay refers to the latter definition. The clay minerals of Utah Lake, ranging generally be- tween 5 and 10 percent (dry weight), belong to the illite, montmorillonite, and mixed lay- er types. The pattern of clay mineral distribution in Utah Lake is not easily defined because, among other things, it is a minor constituent diluted by carbonate and silica. Areas of high concentration, 9 percent or more, are located in the vicinity of the delta of the Spanish Fork River and near the mouths of the Provo and American Fork Rivers (Sonerholm 1973). It is clear that the source of the clay minerals is the detritus carried by the major rivers emptying into the lake. Longshore currents tend to disperse the clay minerals to the deeper waters adjacent to the shorelines. Bingham (1975), studying the distribution of particle sizes of sediment, reports that most of the sediment of the interior of the lake is composed of particles in the silt and clay size range. He, of course, uses the term clay in the first of the senses described above. It is clear that much of Bingham's "clay" is in reality very fine-grained calcium carbonate. Minor Constituents.— Minor constituents of the sediment of Utah Lake are numerous, but, in the main, they consist of calcium sul- fate, probably as gypsum, iron oxides and/or sulfides, and organic material of varying kinds. Of course, water is a major constituent of the natural sediment. It ranges from a few percent to as much as 75 percent or more, depending on sediment type and location. An area of relatively large organic concen- tration is present to the southeast of Saratoga Springs (Bingham 1975). Provo Bay carries a large concentration of organic material due to natural and man-caused biological activity. Powell and Benjamin sloughs also bear large concentrations of organic matter. Summary Statement on Sediment-Commu- nity Relationships.— Bingham (1975) con- cludes that available evidence leads to the conclusion that plant communities of the lake do not associate with specific sediment types. Invertebrate animals, he says, tend to be more selective. Worms, midge flies, gastro- pods, bivalves, and ostracods prefer the car- bonate muds of the open lake. Small crusta- ceans are found in the small, local exposures of tufa, hard rock deposits of calcium carbo- nate, in the vicinity of Bird Island and Lin- coln Beach. We believe that detailed studies will reveal stronger associations between sediment types and various plant and animal communities. The properties and distribution of sediments, in broad outline, have only been learned in the past few years. Much is presently being discovered concerning the plant and animal communities in the lake. Sedimentation Rates.— Accumulation of one stratum upon another in sequence of time permits the calculation of an average rate of sedimentation when the absolute age of two different strata can be determined. In the instance of the core samples from Utah Lake, the uppermost stratum associates with the present time. The age of older, deeper layers may be determined by radiocarbon dating, by association with known geological or climatological events in the past, by in- troduction of components such as chemical contaminants or pollen grains from plants in- troduced by man, etc. Sedimentation rates in geologically young lakes (deep and not subject to large sediment inflows) are typically a few tenths to a few hundredths of a millimeter per year. In Utah Lake, a shallow and geologically old lake, sedimentation rates are expected to be high- er, probably near 1 mm per year, depending on the portion of the lake under consid- eration. Rates are likely to be highest in the vicinity of the mouths of the major rivers, and in the deeper parts of the basin where gravity pulls the soupy water-sediment mixture. Acoustical profiling during the summer of 1975 (Brimhall, Bassett, and Merritt 1976) permitted the recognition at depth of a very persistent layer, the upper surface of which ranges between 8 and 15 m (26 and 49 ft) deep, and whose thickness appears to range between 5 and 10 m (16 and 33 ft). The stra- tum is believed to associate with a dark gray, silty clay found at that depth during explor- atory drilling for the proposed Goshen Bay dike (U.S. Bureau of Reclamation 1964). The position and lithology of the stratum suggest that it is the clay unit of the Provo Forma- tion (Hunt, Varnes and Thomas 1953, Bissell 1963), deposited in deep water some 10,000 1981 Utah Lake Monocraph 35 years ago just before the demise of Lake Bon- neville. If the assignment is substantially cor- rect, and the age is likewise correct, the aver- age sedimentation rate in the deeper portions of the lake ranges between 0.8 and 1.5 mm (0.031 and 0.059 in) per year. These values are consistent with rates observed in similar lakes, and with the known inputs of clastic and dissolved materials to the lake (Fuhriman et al. 1975). The average sedimentation rate, 3.3 cm/yr (0.13 in/yr), calculated by Brimhall (1973) is now believed to be more than 10 times too large. Most of the data presented in that pa- per can be reconciled with the rates tentati- vely assigned above by reassigning the times given to the upper 25 cm (9.8 in) of sediment instead of the upper 250 cm (98 in). It must be emphasized that all these assignments are tentative, but the latest assignments are most consistent with new knowledge gained in 1975, and with comparison of Utah Lake with similar lakes. One of the most urgent problems associated with the lake is the mat- ter of establishing its presettlement history by means of taking several core samples to 20 m (66 ft) deep to delineate that history. In the meantime, the sedimentation rates and his- tory of the lake must remain known only within broad terms. During the summer of 1975, 17 shallow core samples, ranging from 30 cm to 120 cm (12 to 47 in), were collected in various parts of the lake. Cores taken lakeward from the Geneva waste pond showed a mixture of cin- der or slag with sand and lime silt. The rela- tive proportions indicate an average sedi- mentation rate, for the natural components of the sediment, of about 5 mm (0.2 in) per year. Another core taken southeast of Sara- toga Springs in organically rich sediment showed a high organic layer at a depth of 400 mm (15.7 in). Tentatively, this layer is as- signed to a low level of the lake thought to exist about 400 years ago when drought con- ditions persisted over the region (Schulman 1956). If the assignment is correct, the aver- age sedimentation rate at this locality, is about 1 mm (0.039 in) per year. Features in the other cores are not easily recognized, and so no additional information is available from them at this time. Geologic Structures in Lake Sediments Previous Work.— Two geologic maps of the bedrock and alluvial deposits in Utah Valley have been published. That of Hunt, Varnes, and Thomas (1953) describes the northern half of the valley, whereas that of Bissell (1963) describes the southern half. Neither of these maps show faults or geologic structures in the vicinity of Utah Lake or of the rest of the valley except for the Wasatch Fault at the base of the Wasatch Mountains. The ab- sence of the structures from the maps does not mean these investigators concluded that none exist, but rather that erosional processes have made them unrecognizable. The mea.surement and description of gravi- ty anomalies in the vicinity of Utah Valley lead Cook and Berg (1961) to recognize the probable existence of faults in the floor of Utah Lake. Stokes (1962) plots three inferred faults extending in a general northwestward direction along the east side of Utah Valley. The first of these stretches between the east side of West Mountain to the vicinity of Saratoga Springs. The second, from Payson to the middle of Utah Lake, and the third, from the mouth of Spanish Fork Canyon to Orem, American Fork, and Lehi. Markland (1964) demonstrates the probable existence of a fault near Arrowhead Resort. Cluff, Brogan, and Glass (1975) in- vestigated the Wasatch Fault in Utah Valley with respect to land use planning. Cluff, Hintze, Brogan, and Glass (1975) have also investigated the Wasatch Fault in north- western Utah as regards recent to current seismic activity and recent fault dis- placements in Pleistocene strata. Geomor- phic evidence, as well as tree ring data, in- dicate that recent faults in the Wasatch Fault zone may be no older than a few hundred years. Faults.— As an outgrowth of a reconnais- sance study of the deep-water springs of Utah Lake by means of a sonarlike device (Brim- hall et al. 1976), an unusual opportunity was afforded to study the faults and other geolog- ic structures present in the strata underlying the lake to a depth of as much as 25 m (82 ft). The faults beneath the lake are sometimes remarkably displayed (Fig. 8) by thereflec- 36 Great Basin Naturalist Memoirs No. 5 0>^^ 15- 20 100 200 DISTANCE, METERS 300 Fig. 8. The East Goshen Bay Fault, 2.4 km west of Lincohi Point. The top of the profile marks the present lake floor. The lower, dark layer on the left, whose top is 8 m below the floor, is offset on the right by about 5 m to a depth of 13 ni. This stratum, a persistent marker stratum throughout the profiles, is believed to be the clay unit of the Provo Formation, uppermost Pleistocene age. tion profiles obtained by sending pulses of sound waves into the lake floor and by re- cording the reflections, or "echoes" from the strata and structures beneath. Heretofore, geologic structures of this kind, less than 10,000 years old (Pleistocene to Holocene age), have only been inferred to exist in the lake floor by extensions of faults observed in bedrock or alluvium in the lake surroundings, and by geophysical measure- ments such as gravity anomalies. Now, for the first time, the existence, character, and distribution of the faults in the lake floor have been observed. This section .sets forth these findings and reports their significance as they apply to the history of Utah Valley and the management of the resources of the lake and its surroundings. Three major faults (Fig. 9) are herewith designated as the Bird Island Fault, the East Goshen Bay Fault, and the West Goshen Bay Fault, which, along with several minor faults and a few folds, were discovered, mapped, and characterized by acoustical profiling in the summer of 1975. These structures exhibit characteristics that are consistent with faults mapped elsewhere in the valley by previous workers, and they add considerable detail to the knowledge of the structural geology of Utah Valley. The faults are furthermore of considerable interest as regards resource management, inasmuch as some of the major spring areas of the lake appear to be con- trolled to some degree by the distribution of faults in the lake floor. Bird Island Fault- Bird Island Fault (Fig. 9) extends northeastward from the eastern part of Goshen Bay to the west side of Bird Island. It then continues northward opposite the mouth of Provo River, and then passes slightly west of north to the vicinity of the mouth of the American Fork River. The western side of the fault is downthrown rela- tive to the eastern side. Observed dis- placements (past 10,000 years) range from 2 m (66 ft) to le.ss than 0.5 m (1.6 ft). Generally, the larger displacements occur at the extrem- ities of the fault. 1981 Utah Lake Mon()(;haph 37 Fig. 9. The principal geologic structures present in the floor of Utah Lake, and the location of the presently known spring areas(adapted from Brimhall, Merritt, and Bassett 1976). 38 Great Basin Naturalist Memoirs No. 5 The eastern fork of the Bird Island Fault leaves the main fault and passes southward about 3 km (1.9 mi) north of Bird Island and is inferred to pass to the west of the Island toward the east side of West Mountain. The fault is clearly evident in the acoustical pro- files just eastward of Lincoln Point. Since the eastern side of the fault is downthrown nearly 2 m (6.6 ft), it is clear that the block including West Mountain and Bird Island stands structurally high (horst). One could be led to believe that the coincidence of the northern portion of the Bird Island Fault where thermal springs exist with a major spring zone on the eastern side of Utah Lake (Brimhall et al. 1976) accounts for the location of the springs, but we are of the opinion that the fault is at most only a contributing factor. Hydrologic and sedimen- tation factors are thought to be dominant be- cause only a minority of the spring areas is shown to be directly associated with the fault. East Goshen Bay Fault.— The East Goshen Bay Fault forks at a point about 2.5 km (1.6 m) west of Bird Island (Fig. 9). The main por- tion extends southward from the juncture to a position west of, and parallel to, the Bird Is- land Fault in the eastern section of Goshen Bay. Adjacent to West Mountain the two faults are in such close proximity that they may be expressions of a compound fault rather than two separate, distinct faults. Westward of Lincoln Point, the fault exhibits approximately 5 m (16 ft) of displacement. The western side of the fault is downthrown to form a portion of the Goshen Valley Gra- ben. From the juncture, the east fork of the East Goshen Bay Fault passes first northeastward then northwestward through the approximate midsection of the lake to a point about 5 km (3.1 mi) northeast of Pelican Point. The west fork of the fault passes northward of the junc- ture to the vicinity of Pelican Point, where it appears to rejoin its partner northeast of Peli- can Point. The interior block bounded by the two forks of the fault is displaced downward relative to the other blocks; hence, the interi- or block is a graben designated as the Pelican Point Graben. It represents the lowest point of Utah Valley from a structural standpoint. Displacements of the faults boimding the graben range from about 1 m (3.3 ft) to less than 0.5 m (1.6 ft). The larger displacements are found on the southern side of the graben. In general, the displacements are smaller than those associated with the Bird Island Fault. The section of the lake occupied by the Pelican Point Graben appears to have very little spring activity associated with it (Brim- hall et al. 1976). Spring activity along other portions of the fault likewise appear to be slight. West Goshen Bay Fault.- The West Gosh- en Bay Fault extends from the southern por- tion fo Goshen Bay, where it may converge with and join the East Goshen Bay Fault (Fig. 9), to the vicinity of Pelican Point, where it appears to join the east and west branches of the East Goshen Bay Fault. The eastern side of the fault is displaced down- ward, which makes the block bounded by West Goshen Bay Fault and its partner to the east a graben, designated as the Goshen Bay Graben. Displacements on the fault range from approximately 2 m (6.6 ft) to less than 0.5 m (1.6 ft). Southward of Pelican Point 5 or 6 km (3.1 or 3.7 mi), the fault is replaced by a monocline that dips gently to the east. The reconnaissance study of Brimhall et al (1976) shows that spring activity along the fault is very weakly expressed. Minor faults.— The East and West Jumbers Point Faults, though minor faults in terms of length, exhibit some of the most spectacular displacements to be found in the lake. Figure 10 shows the acoustical profile obtained over the northern portion of the West Jumbers Point Fault. A similar fault is displayed on the southern section of the East Jumbers Point Fault. Displacements on the faults ranged from about 5 m to about 1 m (16 to 3.3 ft). The eastern blocks are displaced downward relative to the western. The un- usual offsets on these faults indicate that the section of the lake occupied by these faults is active tectonically. The only other fault to compare is the East Go.shen Bay Fault just west of Lincoln Point (Fig. 8). None of these faults, as observed in profile, exhibited spring activity at the several points tran.sected, although it is entirely reasonable 1981 Utah Lake Monograph 39 100 DISTANCE 200 METERS 300 Fig. 10. A spectacular fault on the north end of West Junibers Point Fault. The right-hand, eastern block is dis- placed downward about 2.5 in. The lower dark layer, between 7 and 9 m on the left side, is believed to be the clay unit of the Provo Formation. to suppose that there are springs at places along the faults. Another small fault, named the Saratoga Springs Fault, lies about 1 km (0.6 mi) east of Saratoga Springs Resort. The eastern side of the fault is displaced downward approx- imately 1 m (3.3 ft) as seen in profile. Almost certainly, some spring activity is associated with the fault, but such activity was not dete- rined conclusively in the acoustical profile transects. Deep-water Springs of Utah Lake During the summer of 1975, a 23-transect reconnaisance study of Utah Lake was made by means of a sonarlike device (Brimhall et al. 1976). It was possible to infer spring and seep areas from the profiles. The distribution of the areas containing springs is shown in Figure 9. Inspection of Figure 9 reveals that less than 10 percent of the floor of Utah Lake is associated with springs or seeps. Most are lo- cated in a zone 1 to 3 km (0.6 to 1.9 mi) from shore on the eastern and northern portions of the lake. The reason for such a distribution is clear when it is realized that the principal water- sheds contributing to the lake occur in the eastern and northeastern zones. The springs/seeps occur in response to avail- ability of water, to the thinning and wedging of permeable, water-bearing strata in a lake- ward direction, to the thickening of fine- grained strata to confine the trapped water in a lakeward direction, and to the devel- opment of a hydraulic pressure by the aqui- fers sloping toward the interior of the lake. Thus, the springs/ seeps occur principally as the result of prevailing sedimentary and hy- drologic conditions. Occasionally the springs/seeps are clearly controlled by faults, but in general, the pat- tern is weak. The northern extension of the Bird Island Fault coincides with the concen- tration of springs/seeps along the eastern side of the lake, but the fault in this section is weak in that its displacement is typically less than 0.5 m (1.6 ft) and the springs/seeps are widely scattered on opposite sides of the fault. It is noteworthy that the faults showing the greatest displacements, the Jumbers Points 40 Great Basin Naturalist Memoirs No. 5 Faults and the East Goshen Bay Fault west of Lincoln Point, associate only slightly, if at all, with springs. If a strong association were present, the investigation during the summer of 1975 would have revealed it. Three separate attempts were made in late August 1975 to sample water from springs previously located by the acoustical profiler, but the results were inconclusive. Vertical profiles, made with a portable Hydrolab wa- ter quality probe, showed no significant vari- ation in conductivity from the surface of the lake to the inferred mouth of the spring /seep areas at three different localities investigated. The quality of water and the quantity of wa- ter being discharged from the deep-water springs is still unknown, and awaits further investigation. Implications for Resource Management The geology of the lake includes its geo- logic history and setting, physiography, drainages, groundwater patterns, sediments and strata, and geologic structures (faults). These form a physical base upon which the plant and animal communities, including those of man, live and adapt, and they form the principal boundary conditions, subject to change by interaction, that impose upon the management of the resources of the lake. The following items summarize some prin- cipal implications for resource management imposed by geological conditions known at the present time. The Life of the Basin.— A significant ques- tion regarding Utah Lake is: How fast is the lake basin filling up? What is the expected life of the basin as presently constituted and operated? Available geological data indicate a rate of filling at about 1 mm (0.039 in) per year over the past 10,000 years, although the rate has likely more than doubled with the settlement and urbanization of Utah Valley. It is equally clear, however, from the charac- ter of the faults present in the lake floor, that the valley is deepening relative to the moun- tains at the same time it is receiving sedi- ment. The displacement on the faults in- dicate an approximately equality of deepening and infilling, or an approximate state of dynamic equilibrium existing be- tween deepening of the basin by the faults and the infilling of the basin by transport and deposition of sediment derived from the sur- roundings. This trend is consistent with the overall geologic history of the region that has been characterized by recurrent movements on the Wasatch Fault since its origin some 30 million years ago. So the depth of the lake, relative to the elevation of the present shore- line, will probably remain constant for the foreseeable future. This does not mean, how- ever, that the resources of the lake could not be improved by artificially deepening the water. Faults crossing proposed Goshen Bay dike.— Although a proposed Goshen Bay Dike will cross some faults and folds, we do not believe they pose a serious threat to the safety or operation of a dike. Displacements would likely be no more than a few tens of centimeters, and probably much less, unless an earthquake of catastrophic proportions were to strike the area. Small displacements, if they occur, can be repaired quickly. The geological condition of the lake.— A point commonly, almost pervasively, misun- derstood by laymen and many experts as well, is that Utah Lake is a senile lake in the geological sense. It is a very shallow lake. It has a very large surface compared to volume. It is characterized by high evaporation rates. It is characterized by high rates of sedimen- tation. The exchange of impurities between water and sediment is likewise large. Many mistakenly believe that the lake can be restored to a pristine state characterized by the waters of the mountain lakes of the re- gion. The essential point missed is that Utah Lake cannot be returned to that condition. The natural history recorded in the sediment cores and profiles show that the lake has been in much the same as its present condi- tion for centuries. This natural evidence op- poses statements purportedly derived from diaries and journals of early settlers and ob- servers that the lake was characterized by clear, blue water. Careful analysis of the con- ditions under which such observations were made indicates that most of them were made from some distant point such as the Point-of- the-Mountain where, even today, the lake has a clear, blue aspect, especially when incident light from the sun bears a critical angle just after sunrise or just before sunset. Reports of clear water and sandv beaches were made 1981 Utah Lake Monograph 41 iiiostlv in the vicinitv of the Provo River or other river inflows where the wide phime of clear water extended away into the lake. Un- der most of the conditions in which such ob- servations were made, the water would have a clear aspect. The character and conditions of observa- tions, both from eyewitness accounts and from die natiual record left in the sediments of the lake can be reconciled to the effect that the lake is and has been geologically old since its inception, with the water being tur- bid but sometimes appearing clear locally or completely, depending on the vantage point and conditions under which the lake was ob- served. The foregoing should not be construed to mean that there have been no significant changes in the clarity of water in Utah Lake with the changes of level occurring over the past few thousand years; it simplv means that the lake has not been a completelv clear lake, in tlie same sense that many mountain lakes are clear, throughout most, if not all, of their histories. Sediment eharacter and distribution.— Re- search completed since 1973 has delineated the broad patterns of composition and grain size distribution of minerals being deposited on the lake floor. In all but the nearshore re- gions, the areas close to the mouths of the major rivers, and in the vicinity of Bird Ls- land, calciiun carbonate exceeds 60 weight percent. Silica and clay comprise most of the rest. In the same regions occupied by the cal- cium carbonate, the grain sizes are mostly and about equally in the silt and clay sizes, between 1/16 and 1/256 mm, and less than 1/256 mm, respectively. In the near-shore portions of the lake, silica in the form of sand is the most abundant constituent. Particle sizes are dominantly in the range between 1/16 and 2 mm. We believe that these relationships have a larger bearing on the character of the plant and animal commmiities than previously re- alized, principally by reason of the lack of detailed study necessary to establish the rela- tionships. Mapping of the lithologies of the near-shore regions and the related plant and animal communities is presently being done in a Water and Power Resources Services en- vironment assessment study associated with proposed diking of Provo and Goshen Bays. Geologic faults in the lake.— The geologic faults discovered and mapped in the floor of the lake during the sunuuer of 1975 pose the same kind of threat that otlier faults po.se in the valley, but none beyond those custom- arily a.ssigned. That they exist and are con- sistent in character and distribution with the Wasatch and other faults bordering the val- ley is interesting and informative. The faults exhibit displacements up to 5 m (16 ft) during the past 1(),()0() years or so, but it is unlikely that such displacements were achieved as the result of a single event. It is conceivable that the floor of the lake could be violently heaved by an earthquake, and that large lake waves could be produced, but, even if such did occur, the damage to the shorelines would probably be incidental to the damage wrought elsewhere in the valley by groimd vibrations and movements. The location and character of springs in the floor of the lake is more determined by existing hydrologic and sedimentation factors than by faults. The faults do appear to con- tribute substantially in a few places, how- ever. In the event of strong earthquakes in the valley, it is not anticipated that the effect on springs in the lake floor would be large. Acknowledgments This article was earlier completed in a slightlly different form for the Moimtainland Association of Governments as MAG Techni- cal Working Paper 12. That work was fun- ded in part by a 208 Areawide Water Quality planning grant from the U.S. Environmental Protection Agency. Literature Cited Antevs, E. 1948. The Great Basin, with special empha- sis on glacial and post-glacial times. III. Climatic changes and pre-white man: Univ. Utah Bull. 38(20): 168-191. 1953. Geochionologv of the Deglacial and \eo- thermal Ages. J. Geo'l. 61:195-230. 1955. Geologic-climatic dating in the west (U.S.): Am. Antiquity 20(4)(l):317-335. Bingham, C. C. 1975. Recent sedimentation trends in Utah Lake. Brigham Young Univ. Geology Stud- ies 22(1): 105- 140. BissELL, H. J. 1942. Preliminary study of the bottom sediments of Utah Lake, Exhibit H of the report of the C'ommittee on Sedimentation: National 42 Great Basin Naturalist Memoirs No. 5 Research Council, Div. of Geology, Washington, D.C., pp. 62-69. 1963. Lake Bonneville: Geology of southern Utah Valley, Utah. U.S. Geol. Survey Prof. Paper 257- B: 101-130. 1968. Bonneville— an Ice Age lake. Brigham Young Univ. Geology Studies 15(4):66. BoLLAND, R. F. 1974. Paleoecological interpretation of diatom succession in recent sediments of Utah Lake. Unpublished dissertation, Univ. of Utah. 100 pp. Bradshaw, J. S., J. R. Barton, D. A. White, J. L. Bangerter, W. D. Johnson, and E. L. LovERiDC.E. 1969. The water chemistry and pesti- cide levels of Utah Lake. Proc. Utah Acad. Sci., Arts, Lett. 46(2):81-101. Brimhall, W. H. 1973. Recent history of Utah Lake as reflected in its sediments: a preliminary report. Brigham Young Univ. Geologv Studies 19(2): 121-26. Brimhall, W. H., I. G. Bassett, and L. B. Merritt. 1976. Reconnaissance study of deep-water springs and strata of Utah Lake. Mountainlands Assoc. Govts., Tech. Report 3. 21 pp. Broecker, W. S., and a. Kaufman. 1965. Radiocarbon chronology of Lake Lahontan and Lake Bonne- ville II, Great Basin. Geol. Soc. American 76:537-566. Cameron, F. K. 1905. Sodium chloride increase in Utah Lake, 1883-1903. Jour. Am. Chem. Soc. 27:113-116. Cluff, L. S., G. E. Brogan, and C. E. Glass. 1973. Wasatch Fault— southern portion, earthquake fault investigation and evaluation. Utah Geologi- cal and Mineralogical Survey. 33 pp. Cluff, L. S., L. F. Hintze, G. E. Brogan, and C. E. Glass. 1975. Recent activity of the Wasatch Fault, northwestern Utah, USA. Tectonophvsics 29:161-168. Cook, K. L., and J. W. Berg, Jr. 1961. Regional gravity survey along the central and southern Wasatch Front, Utah. U.S. Geol. Survev Prof. Paper 316-E. 89 pp. Fuhriman, D. K., L. B. Merritt, J. S. Bradshaw, and J. R. Barton. 1975. Water quality effect of diking a shallow arid-region lake. Env. Prot. Agency Tech. Series, EPA-666/s-75-007. 234 pp. Gilbert, G. K. 1890. Lake Bonneville, miscellaneous documents of the House of Representatives for the first session of the Fifty-first Congress, Vol. 17, U.S. Geol. Survey Monograph 1. 437 pp. Hansen, G. H. 1934. Interpretation of past climatic cy- cles by observation of Utah Lake sediments. Proc. Utah./Vcad. Sci. 11:161-162. Hintze, L. F. 1973. Geologic history of Utah. Brigham Young Univ. Geology Studies 20(3, Studies for students No. 8):181. Hunt, C. B., H. D. Varnes, and H. E. Thomas. 1953. Lake Bonneville geology of northern Utah Vallev, Utah. U.S. Geol. Survey Prof. Paper 257-A:l-99. Jensen, J. J. 1972. A thematic atlas of Utah Lake. Un- published thesis. Department of Geography, Brigham Young Univ. Markland, T. R. 1964. Subsurface water geology of Spanish Fork Quadrangle, Utah County, Utah. Brigham Young Univ. Geology Studies 11:37-66. Richardson, G. W. 1906. Underground waters in the valleys of Utah Lake and Jordan River, Utah. U.S. Geol. Survey Water Supply Paper 157:81. Schulman, E. 1958. Dendroclimatic changes in semiarid America. Univ. Arizona Press, Tucson. 142 pp. Sonerholm, p. a. 1973. Normative mineral distributions of Utah Lake sediments: a statistical analysis. Brigham Young Univ. Geology Studies 21(.3):97-118. Stokes, W. L. 1962. Geologic map of Utah. Utah Geo- logical and Mineral Survey, Salt Lake City, Utah. U.S. Bureau of Reclamation. 1963. Feasibility geology report of proposed Provo Bay dike. GM-70, Cen- tral Utah Projects Office, Provo, Utah. 1964. Reconnaissance geology report of the pro- posed Goshen Bay dike. GM-68, Central Utah Projects Office, Provo, Utah. ViERS, D. E. 1964. The chemical quality of waters of Utah Lake. Report 1, Land Resources and Labo- ratory Branch, Project Development Division, U.S. Bureau of Reclamation, Salt Lake City, Utah. HYDROLOGY AND WATER QUALITY OF UTAH LAKE Dean K. Fuhriinan,' Lavere B. Merritt,' A. Woodruff Miller,' and Harold S. Stock- .\bstract.— This paper summarizes hydrological and water quality findings from investigations by the authors and their colleagues over the past 10 years. Water and salt balances on Utah Lake for the July 1970 to July 1973 period show both evaporation (342,077 ac- ft/vr) and groundwater (114,355 ac-ft/yr) to be somewhat larger than previously estimated by others. Tlie lake is eutrophic, turbid, and slightly .saline, as might be expected in a shallow, basin-bottom lake in a semi- arid area. Overall water quality in the lake is fair to good and appears to be controlled more by natural factors than by the activities of man. An increase in total dissolved solids (TDS) from about 300 mg/1 in major surface and shal- low groimdwater inflows to about 900 mg/1 in the main lake is the most significant water quality change. Of this TDS increase, about one-half results from evaporation of about one-half of the total inflowing water, one-quarter from salts carried by mineralized deep-spring inflows, and the remaining one-quarter from the poorer quality surface inflows to the lake. Calcium carbonate (calcite) precipitation from the lake waters accounts for about 40 percent of the estimated 0.85 mm/vr (0.033 iii/vr) long-term rate of sediment buildup of the lake bottom. This precipitated calcite is postulated to be an important turbidity source in the wave-stirred lake. This paper present.s information on the overall hydrologic features of Utah Lake, in- cluding the results of an intensive study of its water balance during the July 1970 to July 1973 period; it also presents information on the chemical and microbiological quality of both inflowing waters and the lake itself. Utah Lake is a shallow lake with an aver- age depth of 2.8 m (9.2 ft) at compromise water surface elevation of 1368.35 m (4489.34 ft) MSL. Its depth is very imiform more than 1 km (0.6 mile) offshore. At com- promise level, in approximate percentages, 80 percent is deeper than 2.5 m (8.2 ft) but only 20 percent is deeper than 3.5 m (11.5 ft). Maximum depths of about 4.2 m (13.8 ft) oc- cur in the south central portion of the lake west of Bird Island. Figure 1 gives area and volume of the lake as a function of surface water elevation. When the shallow character of the lake is combined with the semiarid climate of the area, a large net evaporation loss occurs from the lake. The main impact of this evapo- ration is an appreciable increase in the con- centration of total dissolved solids (TDS) in the remaining lake water. This evaporation impact is compounded by a large TDS load carried by mineralized springs that occur in the lake bed and near-shoreline areas. The re- sulting TDS concentration of some 900 mg/1 in the lake proper is two to four times higher than the average TDS concentrations of most surface tributaries and groundwater inflows. TDS concentrations vary considerably both spatially and temporally with the temporal variation occurring both seasonally and with longer wet and dry hydrologic cycles. These longer cycles may result in a severalfold in- crease in TDS during drought cycles as com pared to wet cycles. Background on Water Balance Methodology The hydrology of a lake refers basically to identification and quantification of all ele- ments of lake inflow and outflow— an ac- counting for all waters that enter and leave a lake. In a general sense, not relating to any particular lake, the inflows are all surface drainage (including drains, seeps, surface wash, intermittent inflows, well-defined tributaries, etc.), groundwater inflows (in- cluding seepage from saturated shoreline areas sometimes referred to as inflow from bank storage), and direct precipitation on the lake surface. The outflows include surface 'Department of Civil Engineering, Brigham Young University, Prove, Utah 84602. ■Major, U.S. Air Force, SAC, Omaha, Nebraska. Formerly graduate student at Brigham Young University 43 44 Great Basin Naturalist Memoirs No. 5 800 900 Fill. 1. lUah Lake aiea/volimie curves as a function of elevation. tributaries, groundwater seepage (including seepage into shoreline areas sometimes re- ferred to as outflow to bank storage), evapo- ration from the lake surface, and trans- piration from any vegetation growing in the lake. The water balance is often stated as fol- lows: I, + Ig -h P - O, - E = S (1) in which l^ = the volume of water in all in- flowing tributaries; Ig = the volume of all inflowing groundwater; P = the volume of precipitation on the lake surface; O, = the volume of water in all outflowing tributaries; E = the voKuiie of water evapo- rated from the lake surface; and S = the volume of water repre- sented by the rise or fall of the lake level; or in other words, the difference between all inflows and outflows must be equal to the change in lake storage, which may be readily determined from lake level records. Since evaporation is difficult to measure accurately in the field, it is often calculated from the in- flow-outflow equation. This calculation is re- ferred to as a determination of evaporation by the water balance method. Utah Lake Water Balance Studies Fuhriman et al. (1975) reported on Utah Lake water balance studies made over the period of July 1970 to July 1973. This section summarizes the key elements of that study, including refinements in those analyses and results that are first published herein. The objective of the water balance studies was to provide an accurate determination of the evaporation from the lake by the use of equation 1. Previous studies by others on Utah Lake have not had sufficient data to make accurate water balance calculations on a monthly basis.' Intensive measurements of tributary inflow and increased coverage of precipitation dining the 1970-73 period made it possible to make computations on a monthly basis during the April through Octo- ber period, when evaporation was greatest and when evaporation pan data were also available. 'The studies reported herein make use of the water balance equation on a monthly basis except durini; the winter months-November through March- when factors such as freezing of the lake water introduce other variables into the relationship. Evaporation calculations by the water balance equation are therefore, reported monthly from April through October and then one five-month period— November through March. 1981 Utah Lake M ONOGRAPH 45 Water Balance Factors Some hydrologic measurements relating to Utah Lake have been made on a continuing basis for manv years. Others have been made intermittently, and some have been measured intensively over relatively short intervals of a few months or a few years in connection with particular studies. A discussion of measure- ments made and/or utilized in the analyses reported herein are described in the sections that follow. Suiface Inflow — A total of 51 surface wa- ter inflows have been identified as contrib- uting to the lake on a regular basis. The loca- tion and identification of these tributaries are given in Figure 2 and Table 1. Of these, two are measiued on a continuous basis by the U.S. Geological Survey at points near to the lake— the Provo Fliver and the Spanish Fork River. A few inflows are measured on a con- tinuing basis by private or governmental imits. During tlie late spring in 1970, mea- surement stations were established on tribu- taries where none existed and measurements were taken at one- to two-week intervals. In spite of careful identification and mea- surement of the surface tributaries, there are times— such as during the spring thaw or dur- ing heavy precipitation on the lands immedi- ately surrounding the lake— when it is not possible to measure all surface inflow. These inflows must be estimated. Inflow quantities for all tributaries were measiued and tabulated on a monthly basis for a two-year period. Measurements of the larger tributaries were continued for a third year, with the less significant tributary flows being estimated during the third year. A sum- mary of the surface inflow measurements over the three-year period was reported by Fuhriman et al. (1975). These flgures, with some minor adjustments that have resulted from refinements in the earlier evaluations, are given in Table 2. Lake Outflow.— Suriace outflows are con- tinuously measured by the Jordan River com- missioner. Records of these outflows— con- sisting of the Jordan River flow, the Utah and Salt Lake Canal, East Jordan Canal, the Utah Lake Distributing Company Canal, and the LDS Church Elberta Farm Pumping— were Table 1. Utah Lake tributaries: identification codes and sampling points. Station Stream MAG 208 stream code Location UT 01 & 02 Drain Zu 01-00.10 & Zu 02-00.10 UT 03 Dry Creek DRCL-00.31 UT04 Drain Zu 04-00.29 UT05 Drain Zu 05-00.38 UT06 Drain Zu 06-00.38 UT07 Drain Zu 07-00.43 Combined UT 01 & UT 02-measured 100 yds below confluence, E side of Saratoga Rd at 6800 N 0.10 mi E of jet of 9550 W and 7350 N 0.20 mi E of jet of 9150 W and 7350 N at 9" flume Approx. 200 ft W of jet of 8730 W and 7350 N at 9" flume Approx. .50 ft S of jet of 8.350 W and 7350 N at 12" flume At jet of 8000 W and 7350 N at 9" flume VT08 Lehi Sewage Treatment LEW 0-(X).90 Plant and Drain 50 yds E of jet of 7800 W and 7550 N-approx 15 yds downstream from road. Includes effluents from Lehi WWTP. UToy UTIO Mill Pond Drain SPCL 01.10 At jet of diversion works at 7400 W and 7750 N Zu ]()-(K).50 1.25 mi S of jet of 6500 W and 7750 N at small diver- sion gate. Includes effluents from American Fork WWTP. UT 11 American Fork AFWT Sewage Treatment Plant About 0.55 mi S of jet of 6500 W and 7750 N 46 Table 1 continued. Great Basin Naturalist Memoirs No. 5 Station MAG 208 Stream stream code Location UT12 Drain 0.2 mi W and 1.0 mi S of jet of 100 W and 400 S ; free-fall UT13 UT14 Drain UT15 Drain UT16 Drain American Fork River AMFR-0.90 Zu 14-00.38 Zu 15-00.59 Zu 16-00.40 0.75 mi N of American Fork Boat Harbor on 100 W at 9' wide concrete appurtenance 0.1 mi W of jet of 6400 N and 5750 W 0.1 mi E of jet of 6400 N and 5750 W 0.25 mi S of jet of 6400 N and 5300 W at exit from 1' culvert UT17 Drain Zu 17-00.80 Geneva Cannery Drain LINH-00.38 0.25 mi W and 0.15 mi S of jet of 4850 W and 6400 N at bridge over concrete ditch 15 yds S of jet of 4250 W and 5600 N at culvert un- der 4250 W. Includes effluents from Pleasant Grove WWTP. UT19 Drain Zu 19-00.15 0.15 mi N of Geneva effluents recording station on W Geneva Road UT20 Geneva Steel Drain Zu 20-00.14 UT21 Drain Zu 21-00.14 Geneva Steel effluents recording station 0.2 mi S of Geneva effluents recording station on W Geneva Road UT22 Drain Zu 22-00.14 0.5 mi S of Geneva effluents recording station on W Geneva Road UT 23 UT24 Drain Drain Zu 23-00.10 .\t 9" flume on drain 0.9 mi S of Geneva effluents re- cording station on W Geneva Road Zu 24-00.10 1.3 mi S of Geneva effluents recording station on W Geneva Road UT25 Drain Zu 25-00.09 At 9" flume, 30 yds S of dirt road at jet of 4000 N and W Geneva Road UT26 Orem Sewage Treatment Plant ORWT UT27 Powell Slough POWS-(XI75 UT28 Drain Zu 28-00.10 UT29 Provo River PROR-02.82 UT 30 Drain Zu .30-(X).33 UT31 Little Dry Creek Zu 31-00.68 UT32 Drain Zu .32-00.28 UT 33 Flowing Well Zu 33-(K).()l S of WWTP at 2500 W and 1000 S At 5' culverts at S end of slough on dike road. In- cludes effluents from Orem WWTP. On N Boat Harbor Drive, I mi W of jet of Geneva Road and N Boat Harbor Drive At uses gaging station 1300 ft W of bridge on W Geneva Road Discontinued-jet of 3110 W and 550 S 0.1 mi W and 0.25 mi S of jet of 560 S and 2470 W 0.25 mi S and 250 ft W of jet of 1600 W and 1150 S 0.5 mi S of jet 1600 W and 1 150 S and approx 50 ft N of culvert at Big Dry Creek near steel standpipe 1981 Table 1 contiiuied. Utah Lake Monograph 47 Station MAG 208 Stream stream code Location UT34 Big Dry Creek BDRC-01.52 LIT 35 nth West ditch Zu .3.5-00.95 UT .36 5th West ditch Zu .36-00.85 UT .37 University ditch Zu .37-(K)..50 0.5 mi S of jet of 1600 W and 1150 S At jet of 1100 W and 1560 S on south side of road 0.5 mi S of jet of 1,560 S and ,500 W 0.25 mi S-SW in interchange of 1420 S and Univer- sity .\ venue UT38 Mill Race MLCR 02..34 0..35 mi S of .3,50 E and 1.500 S. Includes effluents from Provo WWTP. UT .39 Provo Sewage Treatment PRWT Plant 350 E and 1.500 S UT 40 Drain Zu 40-00.25 Discontinued-S of Provo WWTP 0..35 mi and 0.27 mi E ur4i Rat Farm Drain Zu 41-00.25 S of Provo WWTP 0.35 mi and 0.3 mi E-about 100 vds S of road near metal-fenced enclosure Steel Mill Drain Zu 42-01.00 0.81 mi N of 2400 S and 1050 E (near Kuhni Packing Plant) UT43 Spring Creek SPCS 01.51 0.3 mi N of 2400 S and 1050 E (0..55 mi S of Kuhni Packing Plant) UT44 Hobble Creek HOBC 05.46 0.25 mi S of 2400 S and 0.15 mi W of frontage road at 21" weir. Includes effluents from Springville WWTP. UT4.5 Packard Drain VT46 Drain VT47 Drv Creek VT48 Spanish Fork River Zu 45-01.44 On frontage road 0.85 mi N or .3900 S, 5 yds down- stream from culvert under highway Zu 46-02. 18 0..35 mi W of freeway on .3900 S DRCS-02.46 0.85 mi W of freeway on 4000 S at 9' wide gate. In- cludes effluents from Spanish Fork WWTP. SPRF 01..30 At bridge 3.7 mi W of freeway on Hwy 79. Gaged at uses station 2.5 mi N of Lake Shore (USGS moved 1979). UT 48A East Branch of Spanish Fork River UT49 Drain Zu 49-01.89 3.4 mi W of freeway on 4000 S at culvert under road At jet of Palmyra Drive and .3200 W (.8 mi N of .5200 S and 3200 W) UT.50 Drain UT 51 Benjamin Slough Zu .50-01 .14 At jet of 4000 W and .5200 S BENS-02.94 0.2 mi E of jet 6000 W and 6400 S at bridge over slough. Includes effluents from Salem and Payson WWTPs. UT.52 White Lake WTLK-01.50 Goshen Bay channel— near 3' flume approx V4 mi NW of White Lake on outlet channel to Goshen Bay UT 53 Jordan River JORR-48.45 At bridge on Hwy U-121, 2.3 mi SW of jet with Hwy 73 Italicized stations are "major" tributaries; these are defined as those generally carrying more than 2000 acre-feet of flow each year 48 Great Basin Naturalist Memoirs No. 5 Sa ntaq u in Utah Lake and Environs Goshen 2 3 4 5 scale II Fis;. 2. Location and code nunihcrs for L'tali Lake sampling sites and eode nunilieis of snrface tribntt 1981 Utah Lake Monograph 49 TviiLi: 2. I'tali I.ako siirtace tiil)utar\ iiitlows, 1970-71 (all iisiuies arc in acre-feet of water, 1 acre-foot equals 1233.6 iii^). Totals Tributary 1970 1971 Jul- number Jul Aug Sep Oct Nov Dec Jar^ Feb Mar Apr May Jun Jun 1 44 33 57 26 0 0 0 0 0 17 16 3 196 2 46 25 24 45 0 0 0 0 0 0 2 19 161 3 0 0 0 0 0 0 0 0 0 7 59 37 103 4 24 28 23 32 30 33 33 33 34 32 34 35 .371 5 23 13 37 7 20 16 21 30 14 18 23 67 289 6 138 126 234 69 55 67 73 66 64 73 104 146 1215 7 43 62 37 40 29 34 75 47 40 81 102 65 655 8 353 117 385 436 376 383 404 314 274 316 327 392 4077 9 1287 678 1240 1507 1642 1474 1519 1189 1207 1066 977 1363 15149 10 207 236 275 262 213 185 191 175 181 185 240 269 2619 11 163 129 95 83 74 74 74 76 80 80 117 215 1260 12 64 58 99 80 61 54 60 47 35 61 136 154 909 13 58 67 45 52 44 26 23 21 23 25 49 ,501 9.34 14 148 163 153 155 126 109 120 102 109 128 125 226 1664 15 157 156 153 195 174 155 156 138 156 163 191 189 1983 16 143 73 118 119 99 93 111 111 122 124 146 1,52 1411 17 401 255 356 319 222 156 158 131 159 235 368 472 3232 18 1444 1569 2686 2442 2081 1866 2115 1725 1819 1974 1673 1519 22913 19 1 3 0 0 0 0 0 0 0 0 0 0 4 20 1842 2027 1849 1910 2170 2165 2196 1741 1910 2006 1910 1805 2,3.531 21 0 0 0 0 0 0 0 0 0 0 0 0 0 22 0 0 0 0 0 8 8 6 6 4 2 0 34 23 0 0 0 0 4 6 6 6 6 6 5 2 41 24 12 8 11 17 20 19 22 17 16 15 13 13 183 25 67 98 58 59 82 94 119 88 85 23 72 89 934 26 314 313 289 252 296 217 202 199 225 217 252 260 3036 27 1210 1270 1240 1380 1440 1420 1500 1480 1540 1450 1530 1320 16780 28 7 0 28 35 68 67 182 129 79 87 47 28 757 29 1250 633 1220 9500 20700 23350 19280 17170 13310 18800 11690 19500 156403 31 78 121 164 149 177 160 116 106 119 143 118 66 1517 32 49 44 44 45 42 43 43 39 43 46 47 55 540 33 6 6 6 7 7 7 7 7 6 6 6 6 77 34 743 722 717 669 595 410 337 269 296 358 394 702 6212 35 91 92 199 118 149 132 93 99 45 65 82 75 1241 36 32 64 138 50 26 13 40 130 25 38 76 88 720 37 74 84 94 93 82 63 58 54 58 75 83 72 890 38 867 870 814 1041 1118 1041 990 898 1208 1031 814 825 11517 39 1524 1564 1361 812 948 928 935 828 853 1014 1182 1342 13291 40 232 229 185 247 236 208 184 166 184 167 170 148 2356 41 408 423 416 337 263 273 292 298 346 378 498 461 4393 42 1484 1403 1362 1708 1782 1568 1602 1390 1228 1274 1858 1297 17956 43 743 373 359 278 293 404 673 634 817 923 921 729 7147 44 145 128 758 1366 2002 2049 1979 1834 2178 2731 2012 557 17739 45 170 205 207 226 242 229 209 213 183 140 154 281 2459 46 494 577 422 267 176 217 178 164 178 194 227 523 3617 47 334 924 1134 1361 1211 1291 1211 1158 1215 1159 399 791 12188 48 453 681 2165 4130 5320 5810 6810 6810 9970 13860 10760 1910 68579 49 68 69 56 57 50 34 32 42 44 37 35 58 582 50 261 331 256 288 245 272 303 368 242 277 395 434 3672 51 1454 1645 3242 ,3454 3944 3885 3516 3706 3933 4233 2881 2159 38052 52 0 0 0 0 800 200 538 931 720 354 338 70 .3951 UTP 3000 2000 1000 1000 1000 TOTALS 19056 18695 24811 35725 49734 51308 48794 45185 48385 57696 44661 42490 486540 ''UTI denotes unmeasured tributary inflow. 50 Great Basin Naturalist Memoirs No. 5 Table 2 continued. Totals Tributary 1971 1972 Jul- number Jul Aug Sep Oct Nov Dec Jau Feb Mar Apr May Jun Jun 1 0 4 15 10 0 0 0 0 0 0 25 8 62 2 0 5 23 0 0 0 0 0 0 0 68 1 97 3 0 0 0 0 0 0 0 0 49 0 0 60 109 4 38 35 22 26 31 32 31 .35 30 23 3.3 39 375 5 22 2 19 15 29 0 37 21 17 12 20 32 226 6 159 115 215 63 64 70 74 63 55 60 112 146 1196 7 68 79 135 194 191 97 92 58 30 57 179 74 12,54 8 276 93 298 328 343 310 295 230 178 214 406 .351 3322 9 1387 997 1445 1558 1418 1311 1291 1104 1168 916 375 11,54 14124 10 215 207 220 217 204 180 178 16 213 274 325 233 2482 11 259 141 107 76 74 77 70 66 70 92 104 164 1300 12 73 96 121 114 90 72 49 38 ,50 100 168 178 1149 13 63 60 58 57 58 60 61 58 68 83 105 173 904 14 1,58 231 167 159 133 114 105 89 86 121 149 168 1680 15 123 106 158 178 163 151 129 115 121 135 1.50 177 1706 16 99 103 98 115 98 94 80 71 90 83 121 114 1166 17 348 377 428 378 249 171 141 123 117 179 375 ,506 3.392 18 1374 1678 2693 2466 2020 1863 1654 1377 1353 14,52 11,50 1410 20490 19 1 3 0 0 0 0 0 0 0 6 0 0 10 20 1933 1980 2538 2266 2289 2440 2753 2377 2,541 2509 2440 2313 28,349 21 0 0 0 0 0 0 0 0 0 0 0 0 0 22 0 0 0 0 6 6 6 6 12 ,30 6 0 72 23 0 0 0 0 6 6 6 6 7 7 6 1 45 24 10 13 11 16 21 18 16 15 16 15 15 13 179 25 107 90 45 66 82 103 92 73 61 54 100 78 951 26 262 292 273 245 226 279 290 257 265 266 312 312 3279 27 1210 1270 1240 1380 1440 1420 1500 1480 1,540 14.50 1530 1320 16780 28 17 3 50 75 122 123 111 104 .80 12 55 23 775 29 850 877 1120 15802 20229 20205 16,520 16228 20577 168,54 16723 29437 17,5482 31 104 100 149 137 105 109 123 104 74 89 68 65 1227 32 42 45 40 42 39 42 43 40 49 42 80 125 629 33 3 6 6 6 6 6 7 7 7 7 8 8 77 34 617 354 297 470 242 224 234 224 289 ,321 ,301 ,321 3894 .35 46 54 119 211 214 133 148 35 80 125 141 119 1425 .36 25 24 60 58 26 30 31 23 25 71 25 24 422 37 75 80 92 95 76 55 49 35 37 60 68 69 791 38 859 947 711 883 868 923 959 892 1008 726 7,50 684 10210 .39 1439 1624 1401 12.59 1117 10.55 952 944 1128 1141 1.325 1466 14851 40 404 255 273 206 169 149 123 29 31 .30 18 0 1687 41 313 262 241 245 228 208 215 196 246 .303 240 2,50 2947 42 1529 2057 2116 2241 1040 1468 1279 1294 14,57 1743 2060 23.38 21,522 43 451 414 438 476 468 509 .55.3 ,506 5,53 ,55,3 ,584 779 6284 44 149 191 434 1461 1663 1 766 168 1818 2226 21,30 92 161 14059 45 341 279 331 424 64:5 401 357 276 283 315 240 268 41,58 46 386 456 274 216 203 191 185 127 178 202 240 292 2950 47 489 835 891 941 1073 823 935 1041 1992 1095 689 238 11042 48 593 538 1700 5343 6389 7289 7329 7525 10.320 6926 801 7,36 55489 49 62 54 39 45 44 40 31 35 37 54 49 48 538 50 333 250 207 180 137 135 172 1.50 160 1,S4 :594 303 2605 51 1042 1156 2559 3063 3793 4013 40:^4 .3664 .'5419 2600 1 6,36 2172 .331,52 52 0 0 0 0 2(K) 300 314 713 680 300 90 0 2597 UTI 0 0 0 0 0 8(K)0 0 0 0 0 0 0 8(XK) TOTALS 18355 188.38 23877 43806 49229 57071 45592 43748 53073 44021 ,34951 48951 481512 1981 Utah Lake Monograph 51 Table 2 contimied Totals Tributary 1972 1973 Jul- number Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jun 9 1537 1168 1309 1875 1666 1722 1506 1722 1968 1785 1107 1368 18733 11 129 124 138 143 130 135 143 130 130 140 150 150 1642 IS 1599 1568 2410 2767 2350 1875 1783 1805 2029 1577 1844 1785 23392 20 1745 2372 2313 2593 2602 2579 2782 2250 2271 2063 2265 2405 28240 26 314 314 304 295 285 295 295 266 333 313 285 304 3603 27 1210 1270 1240 1380 1440 1420 1500 1480 1540 1450 1530 1320 16780 29 1840 732 2020 11400 13850 14090 16290 16000 17130 20680 41880 19470 175382 34 679 710 533 429 235 191 188 204 334 502 875 1154 6034 38 813 695 6.32 943 683 1185 1319 1206 1395 1325 678 546 11420 39 1475 1427 1381 1269 933 1135 1009 945 1094 1068 1465 1427 14628 41 286 455 550 524 529 336 240 272 340 374 460 387 4753 42 1020 1072 775 1161 1651 740 526 461 1055 1104 1423 1214 12202 4:^> 861 829 439 689 455 252 144 218 375 371 383 980 5996 47 85 221 416 1072 1133 1156 1128 1137 1270 1187 893 119 9817 48 113 149 762 4950 6320 6450 6550 5730 7300 17090 40150 3480 99044 51 440 336 8,57 2413 2657 2619 2828 3307 3590 3273 3951 2023 28294 52 0 0 0 500 600 700 1200 1200 700 500 250 35 5685 UTI 3721 3416 4331 4929 5134 5278 8900 16700^ 10912 8153 36779 17304 125557 TOTALS 17867 16858 20410 39332 42653 42158 48331 55033 53766 62955 136368 55471 591202 In Febniary abnormal winter thaw caused considerable unmeasured runoff. obtained from Commissioner Brad Gardner. Outflows were tabulated on a monthly basis. Precipitation.— Precipitation on the lake represents inflow to the lake. Precipitation from July 1970 through April 1971 was mea- sured at the regular U.S. Weather Bureau sta- tions at Provo (KOVO Radio Station), Pleas- ant Grove, Lehi, Geneva Steel Company, Payson, and Elberta. Beginning in the month of April 1971, additional measuring stations were established at Pelican Point, Dixon Farms, Lakeshore, and Provo airport. The areal distribution of precipitation on the lake surface was determined by using the Thiessen method of weighted distribution. Total lake surface precipitation was tabulated on a monthly basis. Change in Storage.— Calculation of water balance elements on a monthly basis requires determination of storage volume at the end of each month. A lake water stage recorder is maintained and operated by the Jordan River Commissioner. The water level charts in- dicate that wind can cause considerable fluc- tuation—more than 0.6 m (2 ft) at times— in the water level of the lake. Carefully analyz- ing wind-caused seiches and averaging high and low water levels during such oscillations allowed correction to an accurate end-of- month lake stage. Ground Water Inflow and Outflow The geology of Utah Valley (Hunt, Varnes, and Thomas 1953, Bissell 1963) is such that the area surrounding Utah Lake— and the lake itself— is underlain with low-pressure ar- tesian aquifers. In addition, the water table in the unconsolidated shallow deposits near the lake almost always has a gradient toward the lake. Under these conditions, there is ob- viously groundwater inflow to the lake from a number of different geologic formations. Based on geologic characteristics of Utah Valley, groundwater outflow from the lake is felt to be negligible. Spring.s in the Lake.— It has long been known that a number of springs flow directly into the lake from its bed. Evidences of ex- tensive spring flows into the lake have been noted bv Swendsen (1905), Richardson (1906), Hunt et al. (1953), Bissell (1963), and Mundorff (1970, 1971), who wrote of the ex- istence of such springs and of the general geologic features of the lake that caused the springs. Several attempts have been made to mea- sure the flow of the springs. Harding (1941) made observations over a period of several years and also accumulated information ob- tained from interviews with others relating to 52 Great Basin Naturalist Memoirs No. 5 springs in the lake. Viers (1964) made de- tailed studies of lake springs in an attempt to determine their effect on the lake's chemical quality; he made observations from the air and ground to locate spring areas and then sampled them for quality determinations. He located and identified 30 separate springs in the lake. Milligan et al. (1966) made careful observations, including a number of measure- ments of both quantity and quality, of the nearshore springs flowing into the lake. Han- sen (1975) reports observations of many springs above the water line during the 1934-35 drought, when the lake was at its lowest historical level. Dustin and Merritt (1980) considered the hydrogeology of the lake with emphasis on Goshen Bay and con- cluded that between 12.3 and 22.2 X lOfimVyr (10,000 to 18,000 ac-ft/yr) of groundwater is coming from Cedar Valley into the southern end of the lake. There are many springs in the lake, but it is obvious that field measurement of this source of inflow is virtually impossible. Since it was necessary to input this element as a known quantity in the water balance equa- tion, an indirect method quantifying this in- flow was used to supplement the limited amount of spring flow data available. This method was the use of salt balances as de- scribed later. Evaporation Measurements of evaporation from a U.S. Weather Bureau Class A evaporation pan have been made during the summer months at the Utah Lake pumping station southwest of Lehi for 28 years. The record of these measurements is published in the monthly CUmatological Data for Utah, published by the U.S. Weather Service. However, evaporation from standard pans is different than evaporation from nearby lakes themselves, and the degree of differ- ence depends upon many factors. In fact, ac- curate determination of evaporation from a lake is a very difficult problem since some elements of inflow and outflow are almost impossible to measure accurately. The most intensive study of evaporation from a lake surface ever undertaken was con- ducted at Lake Hefner, Oklahoma, in 1950 and 1951. Harbeck et al. (1952, 1954) report- ed results of this intensive evaporation studv involving many emminent scientists and engi- neers. Many detailed measurements and eval- uation methods were used to determine the evaporation from this carefully selected lake. Prior to this study, lake evaporation was gen- erally estimated by multiplying the pan evaporation by a coefficient that usually was between 0.7 and 0.8. These values were based mainly on work by Rohwer (1931), Harding (1935), and Young (1947). A number of publications reporting on ex- tended Lake Hefner investigations have been issued. Harbeck (1962) wrote on the use of the mass-transfer theory. Kohler et al. (1955) and Kohler and Parmele (1967) reported on studies using evaporation pans and mete- orological factors such as solar radiation, air and water temperature, and dew point tem- perature to develop charts that might be used at other locations to estimate evaporation. Extending these studies to specific locations in the U.S., Kohler et al. (1959) published generalized maps for the U.S. to provide a basis for evaporation estimates. These maps are based upon empirically derived charts utilizing the meteorological factors men- tioned above. The results of measurements at Lake Hef- ner reported by Harbeck et al. (1952) showed clearly that the average pan coefficients for the Class A evaporation pans varied from month to month. Neglecting one month, in which there was apparently some sort of ob- servation error, the coefficients ranged from about 0.4 to 1.32. The low values occurred in the spring of the year when the lake water temperature was lower than the pan water temperature, and the high values occurred in late siunmer and fall when the reverse was true. rrcvious evaporation studies on Utah Lake.— Various studies in the past have re- sulted in estimates of evaporation from Utah Lake. Swendsen (1904) reported use of an evaporation pan at Lehi as early as 1901 in studies by the Salt Lake City engineer to esti- mate Utah Lake evaporation. Jacobsen and Peterson (1932) reported on studies that in- cluded evaporation estimates. Harding (1940) analyzed the available evaporation pan re- cords near Utah Lake over the period 1903 to 1936 to develop estimates of evaporation 1981 Utah Lake Mono(;rafh 53 from tlie lake. He used a constant value of 0.70 for a pan coefficient and then used the Lehi record, extending it by various statis- tical comparisons with other records. In connection with the development of a water resources management simulation model for the Upper Jordan River drainage area, Wang et al. (1973) studied the water balance of Utah Lake. In conjunction, Wang and Riley (1973) also estimated evaporation by the energy budget analysis, even though the necessary measurements of solar radi- ation, vapor pressure, and water temper- atures were not available at Utah Lake. They pointed out the error in the common practice of assuming a constant coefficient of pan evaporation compared to lake evaporation. Using their evaporation estimates in the wa- ter budget analysis in the simulation of lake levels using their simulation model, they achieved a good correspondence between ac- tual and simulated lake levels. However, it should be pointed out that they used a water budget analysis that included estimated val- ues for both groundwater inflow and evapo- ration. These are both unknowns and error in one could be offset by the same magnitude of error in the other. The report of Wang and Riley (1973) includes a plot of simulated lake evaporation versus pan evaporation at Lehi. This graph results in an S-shaped curve in- dicating low values of the pan coefficient during months when the lake evaporation is either in the low or the high range. This seems to be inconsistent with the Lake Hef- ner studies (Harbeck et al. 1952 and 1954), which indicated that pan coefficients were low in the spring and early summer when lake water temperatures were low relative to the overlying air and high in the late summer and fall when the lake waters had stored a significant amount of heat. The U.S. Bureau of Reclamation (1964), in planning for the Bonneville Unit of the Cen- tral Utah Project, used a constant evapo- ration pan coefficient of 0.8 applied to the evaporation pan records at Lehi in making estimates of total lake evaporation. Viers (1964) also used a constant pan coefficient of 0.8 applied to the Lehi evaporation pan re- cord to estimate the lake evaporation. Salt Balance Studies All water balance factors were measured with reasonable accuracy except evaporation and groundwater inflow. Therefore, using the water balance equation alone, it was not pos- sible to determine evaporation by this meth- od. However, additional physical facts aid in the evaluation of evaporation: (1) evapo- ration is known to be relatively small during the winter months, (2) groundwater inflow from deep-seated sources is relatively con- stant, (3) groundwater inflow from other than deep-seated sources is related to groundwater levels around the periphery of the lake, and (4) some of the mineral ions dissolved in the lake waters are sufficiently stable that an ion- balance (salt balance) analysis can provide an additional check on water quantity estimates. The theory of the ion-balance analysis is simple. In effect, it is a mass balance, the same as a water balance, on selected dis- solved minerals in the waters. Ions are chosen that do not ordinarily precipitate out of solu- tion (conservative ions) at the concentrations found. Ion concentrations in all incoming and outgoing waters are used in an equation sim- ilar to the water balance equation. Ion con- centrations must be determined for each in- flow and outflow over time. In many cases, this may be more difficult than obtaining ac- curate water inflow and outflow data re- quired for both water-balance and ion-bal- ance calculations. In the case of Utah Lake, two factors are present that make ion-bal- ance calculations feasible: (1) the mineralized spring inflows contain a much larger propor- tion of sodium, potassium, sulfate, and chlo- ride ions than do most surface and fresh groundwater inflows. Since a large uncertain- ty is associated with the total annual volume of these mineral inflows, this large difference in ion concentrations is extremely helpful in adjusting the magnitudes of fresh and miner- alized groundwater inflows as trial water and ion balances are run; (2) a substantial amount of chemical quality information is available on the major tributary inflows, fresh groundwaters, and major mineralized inflows, as well as for the Jordan River. The water quality simulation model (LKSIM), developed in the study of the ef- fects of lake diking on water quality (Fuhri- 54 Great Basin Naturalist Memoirs No. 5 Table 3. Water budget analysis— Utah Lake 1 July 1970-30 June 1973 (all figures are in acre-feet of water, 1 aci foot equals 1233.5 nr^). Precipitation Shallow Deep on lake Surface subsurface Subsurface Surface Change in Calculated Month surface inflow inflow inflow outflow storage evaporation 1970 Jul 7,234 19,056 6,500 2,,324 45,841 - 66,231 .55,.594 Aug 6,080 18,695 8,500 2,.324 51,332 - 76,792 61,0,58 Sep 15,860 24,811 5,700 2,324 ,33,876 - 26„371 41,191 Oct 9,696 35,725 5,400 2,.324 14,862 + 14,187 24,096 Nov 19,540 49,734 6,200 2,.324 8,896 Dec 12,.538 51,308 6,600 2,.324 16,942 1971 Jan 6,102 48,794 6,800 2,324 23,096 + 200,1 59a .34,916? Feb 11,925 45,185 6,500 2,324 25,904 Mar 2,987 48,385 7,000 2,.324 31, .305 Apr 16„557 57,696 6,4(X) 2,324 .30,042 + 27,519 2,5,415 May 3,815 44,661 5,800 2,324 .38,586 - 22,775 40,789 JlUl 2,522 114,946 42,490 486,540 4,700 2„324 40,282 - 45,024 + 4,672 .56,778 TOTAL 76,100 27,888 360,964 .339,837 1971 Jul 817 18,355 6,500 2,324 48,424 - 84,513 &4,085 Aug 5,223 18,838 9,500 2„324 52,045 - 74,649 58,489 Sep 5,860 23,877 14,700 2,324 .37,200 - 29.899 .39,450 Oct 10,327 43,806 9,500 2,.324 1.3,185 + .38,921 13,852 Nov 7,783 49,299 6,200 2,324 10,322 Dec 10,426 57,071 6,600 2,.324 15,211 1972 Jan 277 45,592 6,800 2,.324 23,790 + 176..301 .33,729' .33,729' Feb 133 43,748 6,.500 2,324 25,791 Mar 2,429 53,073 7,000 2,324 29,334 Apr 9,177 44,021 6,400 2,.324 26,079 + 3.742 ,32,101 May 326 34,951 5,800 2,.324 44,952 - ,50,.356 48,805 Jun 5,278 58,056 48,951 481,512 8,700 2„324 44,488 ,370,821 - 32,229 - 52,672 52,994 TOTAL 94,200 27,888 343,505 1972 Jul 985 17,867 14„500 2„324 51,740 - 90,579 74,515 Aug 4,726 16,8.58 12,5(M) 2,324 52,567 - 75,494 59,335 Sep 5,258 20,410 6,700 2,324 .35,800 - 42,894 41,786 Oct 19,106 .39,.332 5,400 2.324 13,464 + ,35.247 17,451 Nov 6,442 42,653 6,200 2,324 5,286 Dec 4,808 42,158 6,600 2,324 1,773 1973 Jan 7,3,38 48,.331 6,800 2„324 6,779 + 236.67.3* 24,917* Feb 7,147 ,55,033 6,500 2,324 19,714 Mar 9,499 ,53,766 7,(X)0 2,324 26,7.53 Apr 11,727 62,955 6,400 2,324 29,798 + 29.999 23,609 May 8,865 1,36„368 5,800 2,324 ,39,690 + 65,849 47,817 Jun 6,148 55,471 591,202 4,700 89,100 2„324 27,888 44,969 - 29,786 + 129,015 53,460 TOTAL 92,049 328„3,33 324,890 1970-73 ANNUAL AVERAGE 88,350 519,751 86,467 27,888 353,373 - ,342,077 *Five-month total 1981 Utah Lake Monograph 55 man et al. 1975), was used to achieve the re- sults reported herein. Sodium and potassium cations and chloride and sulfate anions were used as the primary ions in the ion-balancing procedures. The process actually involved successive approximations to find the quan- tity of groundwater of particular ion concen- trations, which would result in a good simula- tion when compared to the measured concentrations in the lake. The resulting "fi- nal" water balance is given in Table 3 and a summary of the evaporation results in Table 4. It is noteworthy that the pan coefficient (the calculated lake evaporation divided by the pan evaporation) is relatively low in the spring and increases throughout the summer. This pattern is consistent with the Lake Hef- ner results reported by Harbeck et al. (1952). These simulation studies also resulted in an estimated groundwater input of 141 X lO^mVyr (114,355 ac-ft/yr). Others have esti- mated this inflow to be much smaller— per- haps 37 X l()fi to 56 X 10em3 (30,000 to 45,000 ac-ft/yr) (Harding 1941). Discussion of Water Balance Results Over the three-year period of the study, loss by evaporation was over 1250 X lO^m^ (1,026,000 ac-ft)— an average annual loss of more than 417 X lO^mS (342,000 ac-ft). Evaporation was equal to 66 percent of the surface tributary inflow and 47 percent of the total inflow. Groundwater flow directly into the lake was calculated to be 16 percent of the total inflow and 22 percent of the sur- face tributarv inflow. Table 4. Calculated evaporation'^^ from Utah Lake and evaporation from pan at Lehi, Utah, 1 Julv 1970-30 Jime 1973. Month Calculated Calculated Average lake lake Pan lake area evaporation^'*' Evaporation Evaporation Pan (acres) (acre-feet) (inches) (inches) coefficient 92,018 55,594 7.33 9.39 0.78 89,940 61,058 8.21 8.82 0.93 88,467 41,191 5.58 6.20 0.90 88,292 24,096 3.25 3.47 0.94 94,772 25,415 3.20 5.16 0.62 94,843 40,789 5.18 6.57 0.79 93,817 .56,778 7.32 9.16 0.80 91,890 64,085 8.48 10.88 0.78 89,578 58,489 7.89 9.06 0.87 88,096 39,450 5.37 6.84 0.79 88,222 13,852 1.86 no data - 93,982 32,101 4.10 5.17 0.79 93,284 48,805 6.33 8.87 0.71 92,052 52,994 6.94 9.01 0.77 90,270 74,515 10.01 11.72 0.84 87,914 59,3.35 8.16 8.73 0.93 83,162 41,786 5.86 6.04 0.97 86,055 17,451 2.41 no data - 93,900 23,609 3.00 4.32 0.69 95,360 47,817 5.95 8.23 0.72 95,910 53,460 6.72 8.97 0.75 1970 Jul Aug Sep Oct 1971 .\pr May Jun Jul Aug Sep Oct 1972 .Apr May Jun Ji'l Aug Sep Oct 1973 .\pr .May Jun Calculated by the combined ion balance and water budget method, ^he evaporation pans were taken out of service during winter. •-'Author's note— Information from very recent 1930-79 lake simulatii table. 1 acre = 0.4047 hectares 1 acre-foot = li'iS.S cubic meters 1 inch = 0.02540 meter work indicates lake evaporation to be about 10 percent higher than gi' 56 Great Basin Naturalist Memoirs No. 5 The average evaporation pan coefficients for the summer months are as follows: April 0.70 May 0.74 June 0.77 July 0.80 August 0.91 September 0.89 The average monthly winter evaporation for November through March was 0.0206 m (0.81 in) per month. Lake evaporation as determined by these studies is greater than has been estimated by previous investigators. At least two signifi- cant factors are believed to contribute to the abnormally high evaporation loss from Utah Lake: (1) the shallowness of the lake, which results in the lake contents being more easily raised in temperature than would be the case with a deeper lake, and (2) the wind-caused seiches on the lake (frequent and often as much as 0.6 to 0.9 m (2 or 3 ft), which wet a large area of the shore in the southern part of Goshen Bay with every rise of the water sur- face. A large amount of evapotranspiration subsequently occurs from these areas. Utah Lake Water Quality Tributary Quality Water that flows into Utah Lake originates from a natural drainage area of more than 7550 km2 (2900 mi2). Dwelling in this water- shed area is a 1980 population of about 200,000 people, large numbers of wild and domestic animals, and many industrial and commercial establishments— all contributing wastes that affect Utah Lake. However, a large part of the natural and man-made pol- lution is assimilated in the drainage and lake system such that harmhil effects to the lake are less than might be anticipated. Table 5a gives average temperature and chemical quality data for the larger tribu- taries for which significant amounts of data are available (see Fig. 2 for tributary loca- tion). Data are mainly from the 1970-73 pe- riod. More recent data, particularly for 1977-1980, are not included, but cursory re- view of these more recent data show no sub- stantial differences. From zero to 10 data val- ues were available for each parameter each month; usually 2 or 3 in the winter months and 5 or 6 in the summer months. The values are simple averages; no attempt was made to flow-weight or smooth-out the data. The tab- ulated data are presented in the same format as the lake quality data in Table 7 to facil- itate comparisons. Tributary temperatures are generally about the same as lake temperatures, except in June when late spring runoff waters are 6 to 7 C colder and during the winter months when tributaries are several degrees warmer than the lake. Tributary total dissolved solids (TDS) val- ues of some 250 to 1000 mg/1 may not ap- pear significantly lower than the 800 to 950 mg/1 in the main lake, but inspection of the tributary flow volumes in Table 5b shows that the major inflows— UT13 (American Fork River), UT29 (Provo River), UT44 (Hobble Creek), UT48 (Spanish Fork River)- contain only 250 to 500 mg/1 TDS. Of par- ticular note is the Provo River, which carries average TDS values of less than 300 mg/1. The Provo River carries about 30 percent of the total inflow to Utah Lake, but only about 14 percent of the TDS. Other quality param- eters given follow about the same pattern rel- ative to the lake quality as do the TDS val- ues. Tributary flow rate values given in Table 5b are for 1979, a year closer to average than the 1970-1973 values in Table 2. Lake Water Quality Public consensus would likely classify Utah Lake as badly polluted. However, scientific investigations show this is not true, if we de- fine pollution as the quality degradation re- sulting solely from the activities of man. It must be recognized what Utah Lake is: a basin-bottom lake, the natural recipient of many "pollutants" from its drainage basin; a lake adjoined by marshlakes on its east and south fringes, where most people use the lake; a lake where evaporation removes about one-half the total inflowing water, thus doubling the mean salt concentration; and a shallow lake where sediments are stirred and mixed by wave action, giving the lake a milky gray to gray brown, turbid appearance. Most man-caused pollutants enter in tribu- taries on the east and south of the lake and 1981 Uta H Lake MONOC HAPH 57 Taki.k 5a. \\vniov water (|i alitv val irs lor sc lectcd I't ah Lakc't riijutaries." Temperature— C Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 3.7 6.9 10.5 11.3 14.9 _ 26.0 23.2 20.6 8.8 6.5 4.0 UT13 - - 12.6 10.7 17.5 17.0 - 19.2 16.6 _ _ _ UT18 5.8 6.7 10.8 10.3 15.6 15.0 23.2 22.6 21.9 9.9 8.2 4.2 UT29 4.0 3.6 5.9 8.0 11.5 14.3 25.0 19.6 18.6 7.8 7.4 4.7 UT.^ 6.4 7.8 10.5 11.9 15.1 14.5 17.8 19.7 20.2 9.6 10.7 7.0 IIT38'' _ _ 9.5 _ 16.5 15.9 _ 16.5 _ _ _ UT42 8.9 9.0 15.5 14.3 17.4 _ _ 19.8 18.0 15.6 12.2 _ UT43 4.8 8.3 12.7 11.9 17.9 14.0 19.8 18.0 18.3 8.2 8.9 6.5 UT44 8.2 6.6 7.6 7.7 15.0 14.0 _ 18.6 20.9 10.0 8.9 _ UT45 5.0 8.0 - 12.4 - _ 18.0 20.9 22.1 8.8 8.5 6.5 UT47 2.2 6.1 10.4 10.2 15.3 _ _ 21.8 19.9 10.6 7.8 3.3 UT48 3.9 4.7 6.5 8.8 13.5 16.0 23.2 20.4 18.1 6.0 5.8 1.9 Total dissolved solids- mg/1 Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 AAA 444 388 472 373 _ 411 472 431 410 414 453 UT13 — — 398 341 — 259 — 363 332 — _ _ UT18 560 587 626 618 582 478 562 528 514 507 541 513 UT29 327 271 325 327 245 227 274 289 263 249 257 272 UT34 416 398 453 445 380 364 373 443 371 391 .377 378 UT3S^ - — 378 372 405 387 386 890 394 356 890 _ UT42 798 716 718 741 670 _ _ 1065 684 729 699 _ LIT43 624 582 615 580 561 438 548 627 632 570 599 654 UT44 356 278 327 259 316 335 _ 460 _ 310 294 _ UT45 957 1150 886 958 _ - 496 552 — 692 748 839 UT47 937 1016 991 1086 778 — — — — 851 873 _ UT48 552 490 535 480 496 437 722 906 486 526 494 505 UT51 841 912 883 861 1154 1405 1080 1113 857 825 841 1017 Jan Feb Mar Apr Calcium— mg/1 May Jun Jul Aug Sep Oct Nov Dec 78.5 75.0 74.2 61.9 69.0 70.3 81.0 56.0 74.7 66.0 77.0 _ _ _ 84.5 53.2 72.0 .59.8 _ 82.3 79.0 _ _ _ 94.5 89.0 98.0 85.7 86.0 83.2 98.5 88.0 92.0 76.0 91.5 _ 66.5 59.5 65.8 60.2 55.5 52.1 62.0 60.7 63.2 56.0 56.8 60.7 93.3 85.0 83.8 75.7 87.3 85.2 95.5 50.0 84.0 91.0 86.0 _ - - 69.0 — 71.0 74.2 85.0 100.0 77.0 88.0 85.0 _ 125.0 133.0 113.0 116.0 137.0 _ _ _ 122.0 132.0 132.0 17.0 107.0 111.0 102.0 97.3 109.0 98.5 99.0 84.0 98.0 82.5 107.0 _ 72.7 69.7 66.2 53.8 44.0 65.9 _ 78.0 75.0 73.0 88.0 68.0 - 98.0 93.0 66.8 75.0 87.7 82.0 43.0 81.0 _ 82.5 _ 86.0 83.0 72.8 54.8 70.0 _ _ - _ 87.0 86.0 _ 84.7 81.0 72.2 60,3 62.5 65.9 73.8 80.8 68.2 — 77.4 83.5 102.0 78.0 76.5 64.9 82.0 89.0 92.5 69.0 76.0 85.0 70.6 _ Jan Feb Apr Magnesium— mg/1 May Jun Jul Aug Sep Oct Nov Dec UT 9 19.7 40.3 .38.0 .36.4 .37.7 .34.3 37.0 .30.0 38.7 .36.0 .37.2 _ UT13 — — 29.7 22.8 27.0 17.9 _ 25.3 27.0 _ _ _ UT18 42.0 .32.0 45.3 .39.7 .39.3 .39.0 44.5 37.0 .39.7 .38.0 40.8 _ UT29 16.5 16.5 15.4 14.7 18.5 11.1 15.0 14.8 16.8 1.3.7 14.5 11.7 UT34 21.3 21.5 20.6 20.3 20.0 20.8 22.5 19.0 20.7 21.0 22.8 20.0 UT38^ _ _ 22.0 _ 22.0 21.4 16.0 25.6 18.5 12.0 21.0 _ UT42 43.7 43.5 41.7 .37.7 41.0 _ _ _ .38.0 41.0 40.0 54.0 UT43 42.0 .30.0 31.4 .33.8 29.3 29.0 .34.5 .30.0 44.0 .35.0 .33.0 _ UT44 14.0 17.2 16.5 10.0 11.0 18.4 _ ,34.0 25.0 18.0 15.8 16.0 UT45 - 68.0 60.0 42.8 43.0 41.0 33.5 .54.0 48.0 _ 53.0 _ UT47 54.0 .50.0 49.8 .33.6 .39.5 _ _ _ _ 51.0 ,50.0 _ UT48 .30.7 .34.0 .30.4 25.7 .32.0 .30.4 54.7 49.2 25.8 _ 28.8 31.3 UT51 67.0 66.0 56.0 59.0 83.0 83.0 86.0 81.0 60.0 65.0 64.0 - 58 Great Basin Naturalist Memoirs No. 5 Table 5a continued. Temperature— C Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Sodium— mg/1 Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 20.0 23.3 28.4 23.6 24.7 18.3 ,39.5 22.0 19.7 17.0 20.2 _ UT13 _ _ .30.5 15.3 29.0 ,36.1 7.2 12,3 13.0 _ _ _ UT18 33.0 27.5 40.9 ,39.3 .36.5 25.8 27.0 32.0 31.0 27.0 ,30.2 — UT29 11. .5 11.5 12.8 10.9 12.8 8.7 12.0 10.4 1,3.1 _ 11.0 11.3 UT.S4 1.5.0 16.0 19.0 17.3 16.0 14.2 16.0 1.5.0 16.7 1.5.0 16.7 ,58.0 UT38^ _ — 28.0 _ 31.0 28.0 22.0 33.0 26.5 25.0 _ _ UT42 .37.7 41.5 ,52.3 40.2 40.0 _ — _ 31.0 .33.0 ,33.0 78.0 UT43 .34.7 .37.3 .33.4 ,37.0 37.7 21.5 ,57.5 ,30.0 44.0 ,36.0 .32.0 _ UT44 9.7 10.0 11.4 7.7 8.5 10.0 28.0 27.0 40.0 13.5 11.8 24.0 UT45 _ 12.5.0 105.0 119.0 1,30.0 44.3 44.5 83.0 73.0 _ 1.35.0 _ UT47 169.0 173.0 186.0 122.0 131.0 — — — _ 143.0 1,53.0 _ UT48 .52.7 62.5 53.6 41.0 70.0 56.0 182.0 155.0 63.0 — 57.0 67.7 UT51 94.0 127.0 105.0 117.0 175.0 203.0 200.0 211.0 112.0 11,3.0 127.0 - Bicarbonate— mg/1 Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 329 .304 317 316 292 292 202 241 275 279 .304 453 UT13 _ _ 262 247 293 191 _ 270 208 _ _ _ UT18 383 333 353 372 ,326 317 342 277 336 375 359 _ UT29 189 192 211 192 187 172 191 220 199 _ 194 192 UT.34 289 .300 313 ,306 287 285 243 186 254 314 297 212 ms^ _ — 274 282 281 272 285 294 265 277 474 _ UT42 276 256 249 282 286 — _ _ 271 278 276 _ UT43 287 285 287 291 292 226 246 208 ,361 310 307 _ UT44 233 232 220 198 167 200 — 314 217 260 248 158 UT45 — 558 509 437 455 4,30 295 303 .358 — 520 _ UT47 567 456 545 410 448 _ _ _ — 525 525 _ UT48 290 310 312 309 315 324 380 462 294 _ ,301 296 UT51 477 483 465 464 540 561 416 482 451 520 423 - Chloride-mg/1 Station Jan Feb Mar Apr May Jun J"l Aug Sep Oct Nov Dec UT 9 29.3 26.7 19.0 15.9 19.0 22.0 17.0 31.0 23.0 22.3 23.5 25.0 UT13 _ _ 12.9 12.5 10.0 7.7 _ 15.0 17.0 _ _ _ UT18 46.0 .37.0 .39.3 33.3 ,32.0 ,30.4 ,32.5 47.7 29.0 38.0 41.2 43.5 UT29 18.0 24.0 14.5 10.5 10.2 12.0 12.3 16.6 14.7 21.3 20.4 15.4 UT.34 27.8 23.0 26.2 19.7 20.0 23.2 19.0 ,30.0 20.7 27.3 28.3 26.7 UT38^ - _ 29.0 — 29.0 ,33.8 — 37.0 .32.0 _ 42.0 _ UT42 49.3 49.0 44.7 ,38.2 .36.0 _ _ 63.0 40.0 40.0 42.0 _ UT43 52.0 48.3 35.6 43.8 44.7 24.5 48.5 70.0 53.0 57.3 60.0 80.0 UT44 19.3 17.7 9.4 5.0 10.5 15.2 — 26.0 .30.5 11.0 17.5 31.0 UT45 1.38.0 103.0 100.0 52.2 102.0 ,36.0 26.0 65.3 50.0 87.5 109.0 125.0 UT47 126.0 129.0 127.0 118.0 95.0 - _ _ _ 105.0 115.0 — UT48 71.7 70.0 50.5 37.6 51.2 42.1 121.0 100.0 46.4 87.0 62.5 66.2 UT51 98.0 103.0 85.1 94.0 167.0 157.0 194.0 21,5.0 108.0 123.0 121.0 156.0 Sulfate-mg/1 Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 94.0 103.0 78.2 95.6 99.5 89.5 83.5 93.0 88.0 84.0 87.8 _ UT13 — — 104.0 72.0 — 54.2 63.0 80.5 98.3 — _ — UT18 107.0 98.5 128.0 112.0 IIO.O 108.0 122.0 110.0 90.3 100.0 102.0 - UT29 .53.0 .56.5 55.4 51.0 .52.7 41.6 40.5 40.7 43.3 _ 52.7 ,54.3 UT.34 .53.5 60.8 .54.6 .57.8 ,58.7 .57.5 68.0 ,58.0 .55.0 61.0 60.8 ,59.0 UT3* — - 51.0 - ,58.0 ,52.2 ,50,0 ,55.0 49.5 ,50.0 73.0 _ UT42 288.0 .306.0 .303.0 262.0 ,306.0 _ _ _ 248.0 267.0 265.0 ,3.38.0 UT43 1.32.0 172.0 1.56.0 167.0 124.0 97.0 127.0 116.0 163.0 106.0 143.0 _ UT44 42.0 .38.3 .39.7 25.8 15.0 44.1 146.0 100.0 107.0 32.0 46.8 28.0 UT4.5 — 2.35.0 202.0 ,305.0 124.0 95.0 87.0 144.0 112.0 _ 166.0 _ UT47 182.0 163.0 180.0 248.0 144.0 _ _ _ _ 161.0 161.0 _ UT48 100.0 85.0 87.0 72.4 105.0 87.5 221.0 199.0 102.0 _ 103.0 109.0 UT51 165.0 186.0 150.0 1,32.0 281.0 343.0 298.0 ,329.0 170.0 179.0 148.0 - 1981 Utah Lake Monograph 59 Tal lie Dii coiitiiiuecl. Temperature— C Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Nitrate-mg/1 Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UT 9 1.81 1.88 1.78 1.58 1.32 .84 1.13 .40 1.71 1.73 1.73 1.27 UT13 _ _ 1.18 .557 1.42 .525 _ 6.2 1.80 _ _ _ UT18 2.54 2.23 2.89 2.88 1.90 1.06 1.48 1.65 2.71 1.49 1.40 1.69 UT29 .325 .335 .400 .345 .220 .390 .313 .204 .427 .755 .188 .2(X) UT34 .91 .71 .93 1.22 1.66 2.16 1.92 1.51 .77 .83 .88 .80 UT3* _ — 1.00 .62 1.58 1.03 11.1 4.4 4.4 - - — UT42 .750 .688 .629 .611 .555 - - .605 .36 .68 .79 — UT43 2.16 1.39 1.41 1.69 2.02 — .978 1.88 .34 1.28 1.47 1.05 UT44 .900 .748 .760 .512 .442 1.28 _ .48 1.18 .84 .762 .778 UT45 1.64 1.86 2.27 1.46 2.24 1.97 1.54 1.82 2.92 3.60 1.03 1.22 UT47 3.61 2.46 2.41 2..35 2.49 _ _ — _ 1.94 4.06 4.10 UT48 .892 .467 .513 .440 .496 .58 .438 .433 .457 .35 .320 .462 UT51 1.49 1.71 1.38 1.21 .827 .770 .928 .737 .675 .887 1.11 1.20 Quality data largely from the July 1970-July 1973 period, from 1 to 10 observations were available for each parameter each month. "Mill Race averages are for the sampling sites below the Provo STP outfall. -■No data available. are largely attenuated and assimilated as they pass through ponds, marshlands, and bays bordering the main lake. Turbidity.— During much of the ice-free season, normally April through November, Utah Lake is turbid, exliibiting a milky gray appearance during calm periods to a gray brown appearance during windy periods. This turbidity contributes more than any other factor to the "polluted" image of the lake. In fact, this turbidity is a natural feature of the lake that has only been slightly aggra- vated by the activities of man. The lake bed material is composed mainly of colloidal and fine silt-sized calcite crystals (CaC03), much of which is precipitated from lake waters. These particles are agitated and kept in suspension by natural wave and water current motions. During the ice-free season moderate waves 0.3 to 0.6 m (1 to 2 ft) high occur almost daily; large waves up to 1.2 m (4 ft) or more are created several times a month by moderate to high winds. These large waves thoroughly churn up the lake bed material, producing a gray brown, pol- luted appearance that dissipates slowly over several calmer days to the milky gray state. A green hue is added by algae during most of the summer. Algae growth in the summer and fall in- creases the pH to high levels, often above 8.3, which causes the chemical conversion of abundant bicarbonate anion (HCO3) to carbo- nate (CO3). The carbonate then combines with the abundant calcium cation (Ca++) to form a fine calcite precipitate (CaCO,). These newly formed calcite crystals are nor- mally very small and tend to remain in sus- pension. Over time these crystals grow larger and settle to add to the bottom sediments. Ion balances indicate that about 300mg/l/yr of calcite precipitated during the 1930-79 period. This represents a lake total of 185 X 106 kg/yr (200,000 tons/yr) and an average depth of 0.4 mm/yr (0.016 in/yr) in bottom sediments. Since shallow water sediments migrate to deeper waters over time, the midlake accumulation rate would be somewhat larger. Sediment pro- filing investigations and mineral composition work summarized by Brimhall and Merritt in the geology paper in this publication esti- mate the long-term average deeper water sedimentation rate to be about 0.85 mm/yr (0.033 in/yr) and the sediments to be general- ly 60 to 80 percent calcite, depending on lo- cation. Therefore, about 50 percent of the to- tal sediments and 65 percent of the calcite appear to be originating in the lake itself via mineral precipitation. A disproportionate part of the turbidity likely results from this precipitated calcite and other minor precipi- tates, such as the calcium phosphate com- pounds (Ca,(Po4)y), since these particles are likely smaller than sediments carried into the lake by tributary inflows. Bacterial Contamination Coliform bacteria are frequently used as the indicator of sewage pollution and sani- tary quality of waters. Some coliform bac- 60 Great Basin Naturalist Memoirs No. 5 Table 5b. Flowrates in Utah Lake tributaries during the 1979 water year— a typical, near average year (acre-feet). 1978 1979 Station Oct Nov Dec Jan Feb Mar Apr Mav Jun Jul Aug Sep Total UT1&2 122 20 0 0 0 0 0 170 66 48 13 13 452 UT4 36 25 24 24 30 33 28 0 0 25 25 24 274 UTS 80 80 82 82 82 91 86 114 111 51 51 49 959 UT6 116 120 125 125 110 122 76 76 73 128 128 124 1323 UT7 65 67 70 70 132 153 51 47 45 197 197 190 1284 UTS 346 .351 365 286 4,50 1533 485 377 216 204 323 124 ,5060 UT9 1195 1442 1286 1.534 1406 1664 780 956 1322 503 1242 966 14296 UTIO 3 0 57 118 94 45 23 71 0 33 215 291 950 UTll 191 148 117 109 95 109 115 244 359 360 180 0 2027 UT12 105 48 38 38 38 42 61 52 50 105 105 101 783 UT13 25 45 46 46 82 92 66 1,56 326 200 54 52 1190 UT14 86 105 112 113 109 122 132 41 126 145 173 168 14,32 UT15 191 167 169 168 218 250 133 180 223 213 170 164 2246 UT16 229 120 103 103 62 66 110 73 236 201 123 119 1545 UT17 375 234 172 137 142 76 100 160 341 228 ,331 ,344 2640 UT18 1677 1303 1615 2190 1370 1286 1119 1011 883 1120 1941 1122 16637 UT20 2142 2.333 27.50 2297 2074 2385 2273 2426 2085 1724 18,52 2118 26459 UT23 1 25 31 31 7 6 5 2 2 1 1 1 113 UT25 23 63 74 74 38 38 30 33 144 105 24 23 669 UT26 508 475 477 482 447 492 487 546 ,528 ,571 586 565 6164 UT27 1079 1164 1278 1477 16,33 1363 1179 1023 951 980 1022 1051 14200 UT28 0 103 123 123 131 148 73 40 89 103 123 119 1175 UT29 10.340 147.30 16940 172,50 1,54,30 17,320 17700 6160 2360 963 2570 2,530 124293 UT .31 148 160 169 169 186 210 98 92 1,36 108 48 46 1570 UT 32 62 109 123 123 47 46 57 119 50 49 44 42 871 UT 33 18 18 18 18 17 18 28 37 36 42 92 89 481 UT,34 402 258 317 317 317 ,351 249 178 653 695 ,591 813 5141 UT35 1.54 49 31 31 7 6 1 280 42 93 264 256 1214 UT.36 18 86 103 103 81 87 67 256 115 124 1,56 151 1,352 UT.37 62 55 57 57 65 73 71 94 91 256 280 271 1432 UT 38 499 642 999 1457 679 1115 1286 960 449 ,534 641 539 4800 UT.39 1.342 1240 1207 1180 1160 1294 1206 1446 1496 1979 1874 1832 17256 UT41 403 349 343 282 119 1,57 160 1,34 397 366 513 605 3828 UT42 1210 875 1352 1,356 1314 1655 1437 1768 1891 1,304 1,5,35 1699 17394 UT 43 442 723 870 650 577 663 ,508 ,327 418 110 612 ,584 6484 UT44 1483 2518 .3066 2731 2,337 12,30 9668 1,3091 14227 2632 0 0 52983 UT45 201 294 349 322 ,348 378 270 223 105 63 20 190 2763 UT46 1.35 97 1.33 163 246 181 141 248 243 213 318 178 2296 UT47 945 1042 1605 2102 1,527 866 418 185 46 6 263 49 9054 UT48 2,300 5040 6320 7940 m40 8770 1,5340 10,360 792 181 ,334 ,561 54378 UT48a 31 42 46 46 79 92 55 36 100 94 62 60 743 UT49 15 15 15 15 78 92 41 15 15 60 63 61 485 UT50 106 102 143 110 ,579 238 115 323 400 284 1,50 313 2863 UT .51 15.30 2098 2099 2519 2893 4582 2557 1292 390 370 1036 639 22005 UT 52 .54 187 188 336 2122 1518 612 303 147 0 0 0 5467 TOT.\L .30,495 .39,167 45,607 48,904 45,,398 51,058 59,497 45,725 32,775 17,826 20,345 19,234 446,031 ''Tributaries UT ,3, UT 19, UT 21, UT 22, and UT 40 had no flow; UT 40 is being diverted into UT 41. One acre-foot equals 12.33.5 m'^ teria are always found in the lake. The high- est counts usually occur near municipal sew- age plant discharges and main triljutaries. Headman, Ferguson, and Corollo (1949), in a study conducted prior to the construction of any sewage treatment facilities in the area— when considerable raw sewage was dis- charged—found considerable bacterial pollu- tion near raw sewage discharges along the east shore, as would be expected. However, they also noted the low bacterial levels far- ther out in the lake. Fuhriman et al. (1975) reported considerably lower bacterial counts in these near-shore areas (presumably a re- duction resulting from construction of sew- age treatment facilities) with decreases far- ther out in the lake. Recent samples along the east shore only occasionally exceed the 1981 Utah Lake Monoc 61 generally accepted swimming water limit of loOO total coliform per 100 ml. Higher levels normallv occur at the mouths of tributaries, which are contaminated in various ways. Pol- hition from recreation itself may cause high coliform counts in heavy-use areas, such as boat launches and popular fishing areas. Coli- form counts away from the shoreline and em- bayment areas seldom exceeded 100 MPN/100 ml and are usually much lower. Biochemical Oxygen Demand Biochemical oxygen demand (BOD) is a measure of the readily degradable organic matter; it is defined as the oxygen required for microbes to "stabilize" the organic matter present. Utah ambient water quality stan- dards for recreation and aesthetics (class 2 waters) call for a BOD value of less than 5 mg/1. This standard is intended to protect against gross pollution and to avoid low oxy- gen levels from degradation of organic mate- rial. Culinary supply is an unlikely beneficial use of Utah Lake waters because of high TDS and turbidity. Most BOD data for Utah lake have been taken since 1970. The main lake experiences average summer BOD values of 2 to 4 mg/1, Goshen Bay somewhat higher values at 3 to 6 mg/1, and Provo Bay considerably higher val- ues at 5 to 20 mg/1. Table 6 gives data col- lected during 1975 by Merritt et al. (Moun- tainland Association of Governments, 1976). As can be seen in Table 6, some violations of the class 2 BOD standard occur in the lake. In the main lake, these BOD violations result mainly from dead in situ biomass, mainly al- gae. BOD values are highest with algae dieoff in the fall when high oxygenation from wave- induced mixing largely precludes serious oxy- gen depletion, as is the case during all the ice-free season. Only a few oxygen and BOD tests have been nm on samples from under the ice, and some low oxygen problems exist where the water is less than 1 m deep. They are not pervasive since summer algae have largely died and decomposed before ice cover and fall storms fully oxygenate the lake. Goshen Bay is much shallower, and wave action and turbidity are generally less than in the main lake. Large expanses of emergent aquatic plants and attached and floating al- gae are found in the bay, particularly in the shallows. As this organic debris decomposes in the winter, localized low oxygen or anoxic pockets develop under the winter ice but usually are not widespread. BOD loadings from Goshen Bay tributaries are negligible; hence, this is an imcontrollable problem un- less in-lake measures are taken to control the growth of the aquatic plants. It is likely that Goshen Bay has been essentially this way for thousands of years. Provo Bay and several similar, but smaller, bays along the east side of the lake period- ically carry high BOD values. These values would generally be higher than those of the main lake, even in the absence of man's ac- tivities, as a result of the periodically high BOD loads carried by inflowing tributaries and the high biological productivity in these marsh and pond areas. Thus, even in pre- colonization times, periodic anoxic conditions occurred in these waters. Until the construc- tion of secondary treatment plants in the 1950s most of the sewage generated in Utah Valley drained into Utah Lake imtreated. Table 6. Typical BOD values in Utah Lake (5 day, 20 C values in mg/1). Averages* With Without Number of September September Stationb samples Minimum Maximum sample sample ULll 4 1.6 6.2 2.9 1.8 UL13 4 <1 8.3 3.6 2.0 UL15 4 1.2 11.5 4.5 2.2 GB 2 5 2.0 20.0 6.6 3.3 PB 2 4 7.1 22.1 12.4 9.2 PBll 4 3.6 12.4 6.4 4.4 ^Samples taken in July, August, September, and November 1975. Those taken 13 September 1975 were generally from two to four times higher in BOD than for other months, probably due to a heavy algae dieoff. "See Figure 2 for station location. 62 Great Basin Naturalist Memoirs No. 5 Table 7. Average water quality values for selected locations in Utah Lake. Temperature— C Station Mar Apr May Jun J"l Aug Sep Oct Nov Dec ULll 11.7 9.9 16.9 22.5 23.8 — 18.7 — 4.9 _ UL13 11.0 10.7 19.8 24.5 24.0 18.9 19.0 9.4 5.0 — UL15 _ 10.8 12.1 24.5 24.3 — 18.7 _ 4.6 _ GB 2 — 11.5 13.8 22.2 24.8 21.2 18.4 — 4.5 _ PBll 3.5 12.0 — 25.4 22.1 23.3 17.6 9.4 4.0 2.0 PB 2 4.0 10.2 12.2 14.6 27.0 23.8 17.4 14.5 6.1 - Total dissolved solids- mg/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 794 955 894 923 913 913 922 918 893 856 UL13 880 887 854 924 934 915 889 943 891 938 UL15 1073 840 964 969 925 935 925 925 937 941 GB * _ 965 _ _ 948 _ 1145 _ 890 _ GB 2F _ _ _ 2260 2009 2269 _ _ _ _ PBll 751 762 808 - 906 870 898 890 872 835 PB 2 586 S32 - 584 529 525 563 575 627 - Calcium— nig/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 49 53 58 59 54 46 40 49 51 48 UL13 50 44 58 58 51 46 41 43 42 50 UL15 50 50 62 59 51 48 41 40 44 49 GB 2 — 56 — - 58 45 42 — 49 — PBll _ 54 68 _ 55 45 40 49 49 _ PB 2 - 63 90 - 56 96 39 96 83 - Magnesium— mg/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 52 51 54 53 54 55 59 58 54 51 UL13 52 49 54 .53 54 57 56 58 55 56 UL15 .59 48 58 56 57 58 58 58 56 57 GB 2 _ 54 _ _ 71 64 55 _ 57 _ PBll - 45 54 — 48 58 55 57 58 60 PB 2 - 30 32 - 36 30 43 26 40 - This raw sewage with a BOD of about 150 mg/1 resulted in serious oxygen depletion. Secondary treatment plants discharge a BOD of about 30 mg/1 and increase in sewered population increased the total BOD load en- tering Provo Bay to a point where ambient BOD concentrations are periodically as high as 20 mg/1, or more. Most significantly im- pacted have been the eastern reaches of Pro- vo Bay, which receives urban runoff and treated sewage discharges from Provo and Springville (1980 population of about 85,000 people), and Powell Slough, which receives the treated sewage discharge from Orem (1980 population of about 50,000 people). These discharges compound the natural oxy- gen depletion problem mentioned above and extend the total area affected; however, it is debatable whether any significant increa.se in overall environmental degradation and dam- age results from the marginal oxygen deple- tion caused by these treated wastewater dis- charges. The State of Utah is striving to achieve a reduction in BOD to 15 mg/1 in all waste- water effluents by July 1983. At the present time only Provo is meeting this require- ment—through its enlarged and upgraded sewage treatment facility completed in 1978. Although achievement of this requirement will reduce the ambient BOD somewhat, par- ticularly in the receiving .streams, significant long-term improvement in the aquatic habi- tat of these bays is doubtful. BOD from decaying vegetation, including algae, is likely dominant during the periods when the most serious oxygen depletion occurs, namely in the late summer and under the winter ice. Total dissolved salts.— Total dissolved sol- ids (TDS), which range from 700 to 1000 1981 Utah Lake Monograph 63 Table Sodium — mg/1 Station Mai- Apr May Jun Jul Aug Sep Oct Nov Dec Ulll ns 144 142 141 143 148 160 150 147 140 UL13 160 143 152 144 153 153 159 170 160 168 UL15 190 133 156 168 153 157 170 164 160 162 GR 2"' _ 170 _ — 180 _ 247 _ 160 _ PBU _ 130 145 _ 140 175 172 160 146 _ PB 2 - 60 69 - 81 a3 124 31 54 - Bicarbonate— mg/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 225 246 248 249 228 213 194 212 224 219 UL13 239 250 269 248 226 209 193 195 219 220 UL15 242 ^8 266 254 230 215 247 204 231 229 GB 2 _ 267 _ _ 207 196 168 _ 256 _ PBll _ 224 214 — 201 186 177 207 222 226 PB 2 - 226 2A5 - 140 251 110 252 273 - Chloride ;— mg/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 165 176 178 197 197 206 209 206 195 185 ULI3 _ 190 194 196 201 213 213 228 212 218 UL15 260 179 198 214 245 218 226 223 225 220 GB 2^ _ 222 _ _ 226 260 272 _ 232 _ PBll — 157 173 _ 176 _ 254 273 177 185 PB 2 - 73 49 - 88 88 76 32 62 - Sulfate- -mg/1 Station Mar Apr May Jun Jul Aug Sep Oct Nov Dec ULll 184 202 206 222 226 240 248 245 220 210 UL13 189 198 210 220 229 243 242 254 237 231 UL15 246 208 213 225 238 258 249 251 239 227 GB * - 213 - - 230 296 233 - 229 — PBll _ 157 205 _ 202 248 250 242 216 219 PB 2 _ 124 121 — 141 120 _ 128 146 — ^Values are averages of all available data from 1968 through May 1976, except as noted. This was generally a wet period with lake levels somewhat higher than the long-term average. During lower water level periods, there is less mixing between Goshen and Provo Bays and the main lake; hence, Goshen Bav would have higher mineral levels and Provo Bay lower levels. f'Based on 1975 and 1976 data. 'Hased on 1970 data. This shallow area in the south part of Goshen Bay is affected strongly by lake level. mg/1 in Utah Lake during typical inflow years and lake levels, are relatively high as compared to drinking water standards, which recommend a 500 mg/1 TDS upper limit. Other fresh waters in the area, including the lake's major tributaries, contain about 250 to 500 mg/1. Irrigation water quality require- ments vary, depending on crop type, drain- age, soil, etc., but it is an incipient problem at about 1000 mg/1 in this case because lands irrigated with these waters in Salt Lake Val- ley are already alkaline and poorly drained. TDS in Utah Lake sometimes have rather large spatial and temporal variations. In the past, these variations have not always been properly interpreted. Cameron (1905) in- correctly interpreted an increase in salt con- tent of water samples from the lake in 1904 compared with an 1883 sample as an in- dication that irrigation in the drainage basin was causing permanent decline in water quality. The error of this interpretation was pointed out by Decker and Maw (1933) and by Viers (1964)— who indicated the fallacy of using a single sample at an unknown location on the lake (as reported by Clarke in 1884) as being representative of the entire lake. Viers (1964) presented data to show that the salt concentration in the lake was not per- manently increasing with time. Concentra- tions do increase in summer months when evaporation is high, and they are always higher in Goshen Bay and lower in Provo Bay than in other parts of the lake. Table 7 shows differences in several parameters, in- cluding total dissolved solids, in the lake at 64 Great Basin Naturalist Memoirs No. 5 Fig. 3. Utah Lake water elevation and chloride ion concentration, 192S-194L Table 8. Water and salts percentages to Utah Lake by source— July 1970 to July 1973. Inflow category Annual average volume acre-feet Percent Percent of total loading to Utah Lake TDS Ca Mg K CI HCO3 SO4 Surface 519,751 82.0 Shallow subsurface 86,467 13.6 Deep subsurface 27,888 4.4 TOTAL 634,106^ 100.0 61.3 17.4 21.3 38.8 27.6 33.6 15.3 7.5 76.8 10.3 22.1 37.1 18.1 73.8 30.5 44.8 ^Precipitation is not included since it carries essentially no TDS— see Table 3. different locations by months. Table 7 values are based on data taken during the 196)8 through 1975 period, a relatively wet period with lower TDS concentrations, due to the increased inflow of low TDS surface waters, and high lake levels. During high-level peri- ods, there is more mixing and circulation in the lake proper, as well as with Provo and Goshen Bays, and spatial variations are less pronounced than during lower lake levels. During a prolonged, several-year dry cycle, lake inflow may drop markedly but evaporation continue, thus causing a large in- crease in TDS. Figure 3 .shows this response for the driest period on record, which oc- curred during the 1930s. Data were taken from simulations done by the U.S. Bureau of Reclamation (1961). Chloride ion concentra- tion increased from normal levels of about 200 mg/1 to a peak of 1700 mg/1 during the simimers of 1934 and 1935. Since a propor- tionate increa.se in other ions likely occurred, TDS values in excess of 4000 mg/1 were probably present at that time. Table 8 gives the relative quantities of salts (TDS) carried by major categories of inflow to Utah Lake. These values were obtained from the LKSIM model discussed earlier. The 1981 Utah Lake Monocraph 65 values for deep subsurface inflow are the most open to fiitiue revision, since limited data are available for the mineralized springs. Many of these springs and seeps occur in the lake bed itself and cannot be located and sampled in most cases. Mineralized springs for which some data were available are Sara- toga Hot Springs, Bird Island Springs, Lin- coln Point Springs, Goshen Bay North Springs, and Goshen Bay South Springs. Since the mineralized springs are the major sources of sodiimi, potassium, chloride, and sulfate ions— which were needed to obtain a good salt balance in the lake— the five springs given above were selectively increased in flow volume until the "best" salt and water balances were achieved. In other words, it was assumed that the quality of other uniden- tified mineral springs in the lake could be represented by the quality of those identified. In actual fact, co-mingling of mineral and fresh waters likely occurs prior to emergence into the lake. Values given in Table 8 indicate the large impact that mineralized inflows have on TDS and ion concentrations in the lake— a much larger impact than previously recognized. For example, mineralized springs provide only 4.4 percent of the water but 21.3 per- cent of the TDS, 33.6 percent of the sodium, and 44.8 percent of the chloride. Trophic Condition Utah Lake is highly eutrophic, meaning that it has a large nutrient loading and expe- riences very high algal productivity. Procella and Merritt (1976) reported that algal bioassays on Utah Lake waters, using Sele- nastmm cupricornutum as the test alga, in- dicate phosphorus to be the limiting nutrient, although standard chemical tests indicate a relative abundance of phosphoiiis as well as nitrogen in the water samples. These algal bioassays were Rm on waters collected at several sites in September and November 1975 and May 1976. Tliey postulated that high hardness and high pH of the lake waters result in precipitation and/or chemical bind- ing of phosphorus, thus rendering it less available to the algae. Nearly all bioassays also exhibited a delayed response to phos- phorus and nitrogen additions, indicating that trace metals were not readily available and their release rate from precipitates was a controlling factor in the growth response. This is an expected phenomenon in these high alkalinity and high pH waters, where precipitation of most trace metals with the relatively abundant carbonate (CO=) and hy- droxide (OH ) ions would be expected. Over- all, algae productivity is likely limited in the lake itself by the high turbidity, although no in situ algal-growth experiments have been rim to precisely quantify this factor. Merritt, Rushforth, and Anderson (1976) reported nutrient loadings to Utah Lake as shown in Table 9. About 95 percent of the total phosphorus load comes from .surface tributaries. About 68 percent of this load comes from treated municipal sewage ef- fluents that flow into these tributaries. Some- what less than 68 percent actually reaches the lake since some phosphorus precipitation, sedimentation, and biological uptake occurs prior to reaching the lake. The mean annual total phosphonis concen- tration from all waters flowing into the lake is about 0.20 mg/1, which is an extremely high loading for a "fresh-water" lake with a water retention time of about one and one- half years if based on total inflow and about three years if based on outflow. Evaluations by Merritt et al. (1976) show removal of all phosphorus from sewage effluents would still leave the lake with a "eutrophic" ranking ac- cording to results obtained from a commonly used eutrophication model (Larsen and Mer- cier 1975). These findings cast considerable doubt on the feasibility of controlling algae production in Utah Lake via nutrient control in tributary waters. It appears that sufficient nutrients are present "naturally," i.e., from uncontrollable sources, to provide an abundance of nutrients to the lake as a whole. It also appears that, due to high alkalinity, pH, and hardness, most of the phosphorus and trace metals are chemically bound in precipitates, and nutri- ent availability is controlled more by solubi- lity and solubization rates than by the total nutrient loadings to the lake. In addition, as mentioned above, the turbidity is probably the real factor limiting total algal biomass in the lake, not nutrients. Much larger algal bio- masses are generally observed in lower turbi- dity, sheltered areas, thereby qualitatively supporting this proposition. 66 Great Basin Naturalist Memoirs No. 5 Table 9. Nutrient budget for Utah Lake*. Source Inflow acre-feet /yr Inorganic nitrogen kg/yr Total phosphorus kg/yr Orthophosphorus kg/yr Surface inflow 520,000 Sewage effluents (26,900 Shallow groundwater 86,500 Deep groundwater 27,900 Precipitation 86,500 Total inflow 720,900 Surface outflow ,353,000 72.1 1,745,400 12.0 40,570 3.9 5,500 12.0 32,000 49.0 1,823,470 95.7 184,000 15.1 126,000 2.2 2,780 0.3 520 1.8 5,340 15.9 192,640 159,000 95.5 135,000 65.4 105,000 1.4 2,130 0.3 450 2.8 1,070 82.5 138,650 54,800 75.7) 0.3 0.8 39.5 ^Flows are averages for July 1970 to July 1973, a period from 10 to 15 percent above the long-term average. Nutrient quantities were based primarily on 1974 and 1975 data. Phosphorus data prior to 1974 seem to be inaccurate. Sewage effluents discharge into surface tributary waters and their impact is included in the surface inflow values. These effluents are from the following: Lehi, American Fork, Pleasant Grove, Orem, Provo, Springville, Spanish Fork, Salem, and Payson. These plants serve a combined 1975 population of 144,000. The sewered population is projected to increase to 284,900 by 1995 (Mountainland Association of Governments 1976). 1 acre-foot/year = 1233.5 m'^/yr Literature Cited BissELL, H. J. 1963. Lake Bonneville— geology of south- ern Utah Valley. U.S. Geological Survey, Wash- ington, D.C. Professional Paper 257-B. Cameron, F. K. 1905. The water of Utah Lake. Ameri- can Chemical Society Journal 27:113-116. Clark, F. W. 1884. A report of work done in the Wash- ington laboratory, 1883-84. U.S. Geological Sur- vey, Washington, D.C, Bull. 9. Decker, L. B., and C. E. Maw. 1933. Chemical analysis of Utah Lake water. Proc. Utah Acad. Sci. 10:35-40. DusTiN, J. D., AND L. B. Merritt. 1980. Hydrogeology of Utah Lake with emphasis on Goshen Bay. Utah Geol. Min. Survey Water Res. Bull. 23, Salt Lake City. FuHRiMAN, D. K., L. B. Merritt, J. S. Bradshaw, and j. R. Barton. 1975. Water quality effect of diking a shallow arid-region lake. National Environmental Research Center, Office of Research devel- opment, U.S. Environmental Protection Agencv, Corvallis, Oregon, EPA-660/2-75-007. April 1975. Hansen, G. 1975. Springs along Utah Lake .shore during 1934-35 drouth. Personal interview. Harbeck, G. E., Jr. 1962. A practical field technique for measuring reservoir evaporation utilizing mass- transfer theory. U.S. Geological Survey, Washing- ton, D.C., Professional paper 272-E. Harbeck, G. E., Jr., and M. A. Kohler. 1954. Water loss investigations: Lake Hefner studies, base data report. U.S. Geological Survey, Washington, D.C, Professional Paper 270. Harbeck, G. E., Jr., P. E. Dennis, F. W. Kennon, L. J. Anderson, J. J. Marciano, E. R. Anderson, and M. A. Kohler. 1952. Water loss investigations: Vol. I Lake Hefner studies. U.S. Geological Sur- vey, Wa.shington, D.C, Cir. 229. Harding, S. T. 19.35. Part II, Section of hydrology. Page 507-511 in Evaporation from large water surface based on records in California and Nevada. Na- tional Resources Council, Transactions American Geophysical Union. Harding, S. T. 1940. Reports relating to Utah Lake- Chapter 4, Evaporation. Investigations of the Board of Canal Presidents of the .\ssociated Canals, Salt Lake City, Utah. Unpublished re- port. 1941. Springs rising within the bed of Utah Lake in Reports relating to Utah Lake— Chapter 3. In- vestigations of the Board of Canal Presidents of the .Associated Canals, Salt Lake City, Utah. Un- published report. Headman, Ferguson, and Corollo (consulting engineers). 1949. Domestic and industrial waste water survev of the eastern shore area of Utah Lake. Unpublished report to the Utah County Planning Commission. Headman, Ferguson, and Corollo, Consulting Engineers, Phoenix, Arizona. Hunt, C B., H. D. Varnes, and H. E. Thomas. 1953. Lake Bonneville— Geology of Northern Utah Val- ley. U.S. Geological Survey, Wa.shington, D.C, Professional Paper 257- A. Jacobsen, C B., and W. F. Peterson. 1932. Utah Lake, a storage reservoir. Unpublished thesis, Univ. Utah, Salt Lake Citv. 1981 Utah Lake Monograph 67 Kdiii.Kn. M. A., T. J. NoHDKNsoN, and D. \\. Bakkh. 1959. Evaporation maps tor the United States. U.S. Department of ('ommerce. Weather Bureau, Washington, D.(]. Technical Paper 37. KoHLER, M. .\., T. J. NORDENSON, AND W. E. Fo.\. 1955. Evaporation from pans and lakes, U.S. Depart- ment of Commerce, Weather Bureau, Washing- ton, D.C., Research Paper 38. KoHLER, M. A., AND L. H. Parmele. 1967. (lenerali/.ed estimates of fiee water evaporation. Water Re- .sources Research 3:997-1005. Larsen, D. p., and H. T. Mercier. 1975. Lake phos- phonis loading graphs— an alternative. Working paper 174. National Eutrophic Survey, Pac. N.W. Environmental Research Lab., Corvallis, Oregon. 28 pp. Merritt, L. B., S. R. Rushforth, and S. A. Anderson. 1976. Water quality assessment of major lakes and reservoirs in Summit, Utah, and Wa.satch Counties of Utah. MAG Technical Working Pa- per 14, Mountainland Association of Govern- ments, Provo, Utah. 80 pp. MiLLiGAN, J. H., R. E. Marsell, and J. M. Bagley. 1966. Mineralized springs in Utah and their ef- fect on manageable water supplies. Utah Water Research Laboratory, Utah State Univ. Logan. Report WG 2.3-6. MOUNTAINLA.ND ASSOCIATION OF GOVERNMENTS. 1976. Tabulation of water quality data for selected streams and lakes in Summit, Utah, and Wasatch Counties of Utah. M.\G Technical Working Pa- per 8B, Mountainland Association of Govern- ments, Provo, Utah. 1976. Existing and projected population for the counties, subbasins and municipalities of Moun- tainland AOG for the 1975-1995 planning period. MAG Technical Working Paper 2, Provo, Utah. MuNDORFF, J. C. 1970. Major thermal springs of Utah. Utah Geological and Mineralogical Survey, Salt Lake City, Utah. Water Resources Bulletin 13. 1971. Non-thermal springs of Utah. Utah Geolog- ical and Mineralogical Survey, Salt Lake City, Utah. Water Resources Bulletin 16. Fohcem.a, D. B., AND L. B. Merritt. 1976. Algal bioassay results on selected waters in the M.'\G .Area. MAG Technical Working Paper 27, Moun- tainland Association of Governments, Provo, Utah. 106 pp. Richardson, G. B. 1906. Underground waters in valleys of Utah. U.S. Geological Survev, Washington, D.C. Water Supply Paper 157. RonwER, C. 1931. Evaporation from free water surfaces. I'.S. Department of Agriculture, Washington, D.C, Technical Bulletin 271, December 1931. Swendsen, G. L. 1904. Investigations in Utah. Pages 451-455 in Second annual report of the Reclama- tion Service, 1902-3. U.S. Geological Survey, De- partment of the Interior, Wa.shington, D.C. 1905. Operations in Utah. Pages 494-508 in Third annual report of the Reclamation Service, 1903-4. U.S. Geological Survey, Department of the Interior, Washington, D.C. U.S. Bureau of Reclamation. 1961('r'). The chemical quality of Utah Lake as a result of various oper- ation assumptions. Unpublished report, about 1961. 30 pp. 1964. Definite plan report. Central Utah Project, initial phase, Bonneville Unit. Appendix B, Wa- ter Supply Volume 2 of 3 volimies. Region 4, Salt Lake City, Utah. Viers, C. E. 1964. The chemical quality of the waters of Utah Lake. U.S. Department of the Interior, Bu- reau of Reclamation, Region 4, Salt Lake City, Utah. Unpublished Report of May 1964. Wang, B. H., J. I. Felix, R. L. Gold, C. T. Jones, and J. P. Riley. 1973. A water resource management model, upper Jordan River drainage, Utah. Utah Water Research Laboratory, Utah State Univ., Logan. Report PRWG 91-1.' Wang, B. H., and J. P. Riley. 1973. Evaporation from Utah Lake— simulation of evaporation from a shallow lake, Appendix E of: A water resource management model, upper Jordan River drain- age, Utah. Utah Water Resource Laboratory, Utah State Univ., Logan. Report PRWG 91-1. Young, A. A. 1947. Some recent evaporation in- vestigations. Trans. American Geophysical Union 28(2): 279-284. AQUATIC AND SEMIAQUATIC VEGETATION OF UTAH LAKE AND ITS BAYS Jack D. BrothersoiV .\bstract.— Seven aquatic and seniiaquatic comniiinities surrounding Utah Lake and its bays are described. Sim- ilarities and differences in the community types are discussed. Prevalent species in each type are given. The flora contained 48.3 species, 150 of which were prevalent enough to be included in the quantitative data analysis. Dis- tichlis stricta was the most important and widespread species. Total cover varied in the communities from 10 to 77 percent. Asexual reproduction was shown to increase in importance as moisture in the soil increased. Introduced exotic species were shown to invade most successfully those habitats that show the greatest variability in moisture and/or those that have the greatest internal variation. Initial comments on the vegetation sin- rounding Utah Lake were recorded as early as 23 September 1776. Fathers Atanasio Do- minguez and Silvestre Velez de Escalante and their party camped on that date adjacent to the southeast shore of the Lake, and it was during their stay that they penned the first known records concerning plant communities in the area. They recorded wide meadows, abmidant pasture, and marsh communities on the shores of Utah Lake and noted the preva- lence of poplars, willows, flax, and hemp along the streams and east side of the lake (Chevez and Warner 1976). Other early visits were made to the area by trappers, mountain men, and explorers. However, their written records yield little information on the vegeta- tion of Utah Lake that is not extractable from the Dominguez-Velez de Escalante journals. We leam from their writings of occasional bogs, communities containing reeds and abimdant marsh grasses, infrequent patches of wild sage, and swamps filled with Lemna and Chum (Wakefield 1933). More detailed studies of the plant commu- nities found in and around Utah Lake have been made only in the past 50 years. Cottom (1926) made the first quantitative studies of the vegetation of the lake. He listed 11 for- mations and 20 associations that he described as making up the vegetation aroimd Utah Lake and adjacent Utah Valley. Wakefield (1937) reported on vegetational changes over a six-year period on the lakeshore south of the present Provo boat harbor. Beck (1942) and Murphy (1951), in conjunction with stud- ies of passerine birds found in the vicinity of the lake, studied and classified the plant com- mimities frequented by the birds on Bird Is- land and the area from the mouth of Provo River to the south end of the Provo Munici- pal Airport. Barnett (1964) studied waterfowl habitat at Powell's Slough on the east shores of the lake. He placed the vegetation found there into four major communities based upon habitat type and plant species present. Christensen (1965) studied two Tamarix ramosissimo-Salix amygdaloides stands near the mouth of the Spanish Fork River and pre- dicted that ramosissima (which he imder- stood to be T. pentrandra) as a type would eventually replace Solix amygdaloides as these trees die. Foster (1968) in a statewide study of the major plant communities of Utah recognized four community types around Utah Lake. His plant community types are broad in definition and based on observation rather than analytical data. Coombs (1970) examined the vascular aquatic and semi- aquatic vegetation around the lake and de- limited 29 plant communities in 7 major types. Local taxonomic and ecological studies (e.g.. Weight 1928, Leichtv 1952, Lawler 1960, Bessey 1960, Arnold 1960, White 1963, Skougard 1976) have been of great value by identifying many of the plant species grow- ing in and aroimd the lake. Even though Utah Lake and its environs is in many localities well studied from the natu- ral history and ecological points of view. 'Department of Botany and Range Science. Brigham Young University, Provo. Utah 84602. 68 1981 Utah Lake M ONOGRAPH little has been reported in the literature with regard to (1) man's impact on the plant com- mimities since settlement, (2) the influence and changes wrought by introduced exotic plants, (3) species composition for the major commimity types, (4) environmental factors influencing the distribution of major commu- nity types, (5) community diversity, and (6) information with regard to successional changes and life form patterns along environ- mental gradients. Methods Forty stands of data were selected from the hterature (Coombs 1970, Bamett 1964, Christensen 1965) and combined with 10 stands studied by the author in the summer of 1974. Percent sum-frequency values for each species (Phillips 1959), total cover informa- tion (Brown 1968), and moisture index values (Coombs 1970) were then assigned to all 50 stands. Percent sum-frequency figures were used to give the species data from the differ- ent sources equivalent standing. Where in- formation was questionable and /or lacking (especially with respect to moisture informa- tion), supplementary field observations were made in the summer of 1976. Of the stand data taken from the literature only those hav- ing relatively complete information were used in this analysis. Species lists (150 total) were assembled for each stand. Importance values (Warner and Harper 1972) were then computed for each species in relationship to the total vegetative complex and the major communities found in the area. From this information, prevalent species tables were compiled (Tables 4-9). The number of prevalent species included on any one list was equal to the mean number of species reported for the stands of a given commimity. The prevalents are listed in de- creasing order of importance and are the most frequent species in the community; un- common or rare species are ignored. Diversity indices (McArthur 1972) were computed from the percent sum-frequency data using the formula: where Di is the diversity index and pi is the relative proportion each species contributes to the overall composition of a community. Ultimately, each stand and/or community was compared to all other stands and/or commimities. This process resulted in the production of interstand or intercommunity similarity index values (Ruzicka 1958). A matrix of similarity index values was con- structed. The similarity values were clustered by the pair-group clustering procedures de- scribed by Sneath and Sokal (1973). Moisture index data were assigned to each stand using a modification of the methods employed by Coombs (1970). Moisture class- es were set up as reported in Table 2. Floristics and nomenclature follow Cronquist et al. (1977) for the mon- ocotyledons and Holmgren and Reveal (1966) for the dicotyledons. Results General Vegetation Descriptions The aquatic and semiaquatic communities surrounding Utah Lake form a band of vege- tation along the lake shore varying in width from 20 m or less on the western shore to 400 m on the eastern shore. In addition, two large bays, Provo Bay and Goshen Bay, extend away from the lake in eastern and southern directions, respectively, and contain a major- ity of the land area occupied by the aquatic and semiaquatic communities. During this investigaton 483 plant species were found to be part of the Utah Lake vege- tation. Of these, only 150 were of sufficient importance to include in the quantitative data analyses. Only 13 species were included in a prevalence list for the entire area and, as can be seen from Table 1, the list is highly Table 1. The prevalent species found in the vegeta- tion of Utah Lake with their importance vahie. Scientific name Importance value Distichlis spicata 3364 Scirpus arnericamis 2587 Eleocharis palnstris 2315 Jtincus balticus 1832 Carex nebraskensis 1318 Tamarix ramosissima 1094 Scirpus acutus 1039 Hordeiim juhattim 1033 Typha latifolia 1030 Lemna minor 945 Sporohohis airoides 662 Salicornia rubra 606 Ambrosia ariemisifolia 586 70 Great Basin Naturalist Memoirs No. 5 dominated by grasses and sedges, with Dis- tichlis stricta being the most important and widespread species. Seven major vegetative types exist around the Lake (Tables 2 and 3), each occupying unique habitats and each showing varying de- grees of internal structure with respect to subcommunity dominants. This sub- community variation is related in some de- gree to the prominance of asexual reproduc- tion (by rhizomes) in the dominant species. When dominant species reproduce vegeta- titively, large areas may be occupied almost exclusively by a single species or clone even though the abiotic environment is homoge- nous. Average values for selected environmental variables are given for the seven major vege- tative types in Table 2. It will be seen that the number of stands considered for each community is not equal, varying from 5 to 16. The communities vary with respect to moisture from continuous inundation to sea- sonal inundation, and finally to those that never experience standing water or high wa- ter tables. Communities on the dry end of the Table 2. Selected environmental characteristics of major plant communities surrounding Utah Lake. No. Variation- Exposed Percent Percent ID stands Moisture' in surface soil litter Community no. considered index moisture water exposed cover Pondweed communities 1 5 1.0 0.0 91.20 0.00 0.00 Bulrush-cattail marshes 2 7 1.0 0.0 26.47 2.51 20.64 Spikerush-bulrush meadows 3 7 1.75 0.26 7.57 5.07 13.02 Grassnish-sedge meadows 4 16 2.13 0.34 1.16 15.52 6.67 Lowland woodv communities 5 11 1.86 0.43 23.90 12.53 12.18 Saline terrestrial communities 6 5 3.20 0.34 0.00 72.20 1.90 Annual herbaceous communities 7 4 2.50 0.51 0.00 50.55 20.70 'Moisture index is as follows: (1) substratum inundated continuously; (2) substratum seasonally saturated; (3) substratum v -Moisture variability is expressed as a coefficient based on variation on means and standard deviations of moisture index i ■ell drained; (4) substratum dry. alues for individual stands. Table 3. Biotic characteristics of major plant commimities surroimdirtg Utah Lake. Community Type Community Bulrush- Spikerush- Grass-rush- Lowland Saline Annual characteristic Pondweed cattail bulm,sh sedge woody terrestrial herbaceous ID no. 1 2 3 4 5 6 7 X no. of species/ stand 1 12 17 18 9 5 19 X percent living cover 9.8 40.0 74.4 76.6 53.5 26.1 28.8 X diversity 0.1 4.1 6.0 6.8 3.31 2.9 10.4 Dominant Aquatic Cattail Sedge Sedge Shrub Shrub .Annual life form forb sedge forb grass annual Trees °0.0 0.3 0.2 0.2 13.1 0.0 0.3 Shrubs 0.0 0.3 0.1 0.4 43.4 49.5 3.3 Grasses 0.0 3.3 14.6 28.5 16.1 4.7 8.5 Sedges 0.0 31.3 47.0 40.1 5.5 0.0 4.8 Forbs 100.0 26.8 25.6 21.5 9.1 0.7 22.4 Annuals 0.0 7.8 12.4 9.4 10.5 45.2 60.7 Cattails 0.0 26.5 0.2 0.1 0.3 0.3 0.0 Nonvascular 0.0 3.9 0.0 0.0 0.0 0.0 0.0 Introduced exotics 0.0 1.4 10.7 9.7 38.4 5.4 33.9 'Numbers represent percent relative frequency 1981 Utah Lake M ONOGRAPH 71 Table 4. The prevalent species found in the hnlrnsh- cattail marsh communities of Utah Lake with their im- portance values. MOISTURE INDEX WET DRY Fig. 1. Variation in moisture in the communities of Utah Lake in relationship to moisture index. scale exhibit the greatest fluctuations in mois- ture (Fig. 1). The amount of exposed soil var- ies among the communities from less than 15 percent to slightly less than 50 percent in the playa and beach communities. Compositional data for the seven commu- nity types is given in Table 3. Each commu- nity is dominated by a different set of life- form types, with annuals being especially prevalent in the playa and beach areas. In only two cases do particular life form types become sufficiently abundant to contribute over 50 percent of the plant cover. General- ly, the vegetation of the communities consid- ered includes species from several life form classes. Diversity measurements varied from low values for pond weed communities to high values for the annual herbaceous commu- nities. However, even though the diversity indices varied considerably, no significant correlations could be established between di- versity and other parameters. Similarities between the seven community types are evident since some species show dominance in more than one type (Tables 4-9). To better understand these inter- relationships and to assess the degree of uniqueness of the different community types (Tables 2 and 3), a graphical summary of in- tercommunity similarity is presented (Fig. 2). Scientific name Importance values Typha latifolia Lemna minor Scirpus actitus Berula crcrta Eleocluiris palusths Spirodchi polyrhiza Riccia fluitans Polypogon monspeliensis Epilobium adenocaulon Lycopus Ittcidus Nasturtium officinale Scirpus americanus 6243 5471 3457 1771 1257 957 657 614 314 3(K) 286 Table 5. The prevalent species found in the semi- aquatic herbaceous meadow communities of Utah Lake with their importance values. Scientific name Importance values Eleocharis palustris Carex nebraskensis DistichHs spicata Scirpus americanus Trifolium hyhridum Lycopus lucidus Scirpus validus Panicum capillare Polygonum coccineum Polygonum amphibium Iva axillaris Plantago major Ambrosia artemisifolia Agrostis alba Bidens eernua Polypogon monspeliensis Xanthium strumarium 9229 4914 2929 2271 2029 1629 1429 1371 1357 1100 943 943 800 771 714 614 557 In the cluster diagram, communities that are most similar appear close together. The hori- zontal line connecting any two communities shows the degree of similarity between those entities. Figure 2 demonstrates that each community recognized is highly unlike all other commimities considered. The most sim- ilar entities are the Spikerush-bulrush mead- ows and the Grass-rush-sedge meadows, which are only 25 percent similar. Other sim- ilarity patterns exist, but the similarity per- cents are so low that the community types in- volved can be considered essentially independent of each other. Community Type Descriptions Pond Weed Communities The pond weed communities are contin- uously inundated by water. They are essen- 72 Great Basin Naturalist Memoirs No. 5 Table 6. The prevalent species found in the grass- rush-sedge meadow communities of Utah Lake with their importance values. Table 9. The prevalent species found in the annual herbaceous communities of Utah Lake with their impor- tance values. Scientific name Distichlis spicata Scirpus americanus Juncus balticus Eleocharis palustris Hordeum jiibattim Carex nebraskensis Sporobolus aeroides Glaiix maritima Ambrosia ortimisifolia Potentilla anserina Lycopus hicidus Trifolitim hybridum Pohjpogon monspeliensis Ranunculus cymbalaria Phntago major Iva axillaris Aster brachyactis Suaeda occidentalis Importance values Scientific names Table 7. The prevalent species found in the lowland woody communities of Utah Lake with their importance values. 7206 Polygonum lapathifolitim 6650 Chenopodium glaucum 5033 Xanthium strumarium 2125 Panicum capillare 2113 Sesuvium verrucosum 1756 Malva neglecta 1588 Ambrosia artemisifolia 1488 Scirpus maritimus 1156 Aster frondosus 994 Verbena bracteata 838 Distichlis spicata 819 Pohjpogon monspeliensis 613 Sitanion hystrix 606 Rumex crispus 606 Trifolium spp. 438 Sporobolus airoides 381 Tamarix ramosissima 363 Grindelia squarrosa Salix exigua Taraxacum officinale 1 the lowland Medicago sativa Importance values 5700 4100 3700 3700 2150 1950 1900 1650 1550 1450 1450 1100 950 850 850 800 700 450 450 450 450 Scientific name Importance values Tamarix ramosissima Salix amygdaloides Salix exigua Distichlis spicata Elaeagnus angustifolia Hordeum jubatum Populus fremontii Myriophyllum verticillattim Xanthum strumarium 4573 2345 2291 1964 1809 1036 982 873 791 Table 8. The prevalent species found in the saline terrestrial communities of Utah Lake with their impor- tance values. Scientific names Importance values SalicornUi rubra 6060 AUenrolfia occidentalis 5460 Kochia americana 3840 Sarcobatus vermiculatus 1340 Suaeda nigra 1290 tially monospecific (Potamogeton latifolitis) types that occupy the open water areas of the lake. No other communities are found at equivalent depths. As a consequence, this community is analytically distinct from all other communities. Stand dimensions in the lake range from about 8 to 400 square feet (the largest being some 40 feet long by 12 feet wide). Stands occur in water as deep as 8 feet, but depth is variable. Coombs (1970) re- corded that in June 1967 David A. White counted 137 stands in the open water of Utah Lake. Stands are found along the shoreline less frequently. Bulrush-Cattail marshes The Bulrush-cattail marshes also tolerate continuous inundation. The water depth fluc- tuates but generally does not exceed 2 feet and is often at ground level. The soil is char- acterized by considerable organic matter. Stands supported 12 species on the average but were dominated by Tijpha latifolia and Scirpus acutus (Table 4). In general appear- ance, this type appears somewhat like a giant jigsaw puzzle, with the major dominants growing in dense monospecific stands and overlapping with each other in only narrow zones. Along their edges and in areas where the cover is more open, one finds more mix- ing of the dominant species and increased species diversity. It is in these more open areas that many of the subdominant species (Table 4) are found. The community occurs in three major hab- itat types (i.e., in the lake, adjacent to spring- fed bogs, and along irrigation canals). The type is extensive around the entire shoreline 1981 Utah Lake Monograph 73 % SIMILARITY J^ ^ SPltCERUSH- BULRUSH MEADOWS ^ GRASS RUSH -SEDGE MEADOWS „ LOWLAND WOODY COMMUNITIES ^ ANNUAL HERBACEOUS COMMUNITIES , ^ BULRUSH CATTAIL MARSHES . o. SALINE TERRESTRIAL COMMUNITIES , ^ PONDWEED COMMUNITIES Fig. 2. Community similarity analysis reported as a cluster diagram based on plant composition of the Utah Lake commimities. of the lake, but reaches maximum devel- opment m Provo Bay and Powell's Slough. Whether Scirpus acutiis or Typlia latifolia dominates any particular marsh seems to be largely a matter of priority, according to Cottam (1926). This observation tends to sup- port the concept that the subcommunities de- fined by Coombs (1970) can be partially ac- counted for by patterns in asexual reproduction of the dominant species. Spikerush-Biilmsh Meadows The spikcRish-bulrush meadow commu- nities are generally situated in areas that are inmidated in the early seasons of the year but dry by September. The soil of the community varies but generally consists of peaty sandy loams (Coombs 1970). Organic matter con- tent of the soil is high and, in places, the community occurs on peat beds that are 30 inches deep. The type averaged 17 species per stand; several species share dominance. The two most important species are Eleo- charis macrostachya and Carex nebrascensis (Table 5). The community is restricted to the eastern side of the lake extending from near White Lake in Goshen Bay to the Jordan River, but is best developed in Benjamin's Slough and Provo Bay. The major component species appear to distribute themselves in predictable ways in space— as subdominants of the community. Scirpus validiis for ex- ample, is often found in nearly pure stands surrounded by mixed zones of Eleochraris macrostachya and Carex nebraskensis. These latter species generally give way to areas dominated by Distichlis stricta. The relation- ship appears to be associated with a water gradient in which moisture increases as one moves toward areas dominated by Scirpus validus (Coombs 1970). Again one sees local areas dominated by single species that repro- duce vigorously by asexual processes. Grass-Rush-Sedge Meadows The grass-rush-sedge meadows inhabit the largest area of any of the semiaquatic her- baceous communities described thus far. They are situated geographically much like the spikerush-bulrush meadows, but tend to differ in at least the following ways: (1) al- though seasonally saturated the excess water has generally drained away by late spring, (2) the soils generally are less peaty, and (3) the soils are often slightly to moderately saline. This community shows the greatest inter- nal variation and as a result exhibits the high- est mean diversity value (Table 3), which is exceeded only by the annual herbaceous communities. The community averaged 18 species per study unit and is the only commu- nity dominated by grass (Table 6). Of the 8 most important species, 6 are considered to be salt tolerant. The community is extensive (found throughout the study area) and often occupies sites lying between upland shrub types and the communities already described. There is a great deal of subdominant varia- tion within the type that appears to reflect patterns of asexual reproduction on the one hand and islands of local habitat variation on the other (i.e., pockets of peat loam soil dom- inated by Carex nebraskensis, etc.). Again, the major dominants and subdominants segre- 74 Great Basin Naturalist Memoirs No. 5 gate along a moisture gradient. The sedges {Scirpus americanus, Eleocharis macro- stachya, and Carex nehraskensis) tend to be dominant on those areas of seasonal in- undation, and the grasses {Distichlis stricta, Hordetim fubatum, and Sporoholus aeroides) tend to dominate the higher dryer areas. Lowland Woody Communities The lowland woody community is a broad- ly scattered type occupying a variety of dis- jimct sites about the lake. It is among the three most extensive communities surround- ing the lake and is found most often in sea- sonally submerged sites often near flowing streams. The soils are predominantly mineral (sandy to sandy clay loams) with varying de- grees of incorporated organic matter. The community averaged only 9 species per stand (Table 7) and yielded one of the lowest diver- sity indices (Table 3). Of the woody domi- nants listed, 3 are shrubs and 2 are trees. There are two layers in the community, the tree-shrub overstory and a grass-annual or aquatic herb understory. The aquatic her- baceous understory is important only in areas where willows are dominant. There is a high degree of subdominant variation and internal heterogeneity in the community. However, in this case, as opposed to previous described types, the majority of the variation is due to habitat differences rather than asexual repro- ductive patterns. Tamarix ramosissima and Elaeagniis ang- ustifolia, two of the most important species listed (Table 7), are exotic invaders. Since they occur in the overstory and since T. ramosissima is the most widely distributed plant in the type, it appears that this type has been more extensively modified by human activities than any other community consid- ered here. Coombs (1970) considered both species to be increasing and suggested that much of the woodland community is in vari- ous stages of recovery from disturbance. If his evaluation is accurate, it appears that the woodland community will undergo a great deal of change in the future. Saline Terrestrial Community The saline terrestrial community is the most geographically restricted type discussed thus far. It is essentially confined to Ben- jamin's Slough, Goshen Bay, and surrounding areas. The soils vary from sandy clay loams to heavy clays and are generally poorly drained and alkaline or saline in nature. Soil erosion is often evident and disturbance from several sources is generally apparent. Salt content in the soil varies greatly in both lateral and ver- tical space. Variation in salinity combines with variation in soil moisture and local to- pography to produce small scale hetero- geneity in the vegetation. The soils in many areas are seasonally wet, but the communities are not required to develop under water. Small drainage basins are scattered throughout the type and act as receptacles of spring nmoff. As the trapped water evapo- rates from these catchment basins, salts and other materials carried there by the water are left behind. Salt pans or playas develop in such areas. It is around such playa areas that a majority of the vegetational variation is found. This variation is accounted for by con- centric rings of vegetation that surround the playas. Terrestrial saline communities are low in species diversity (Table 3) and average only five species per stand (Table 8). Of the dominants listed, all are salt tolerant and two (i.e. Kochia americana and Suaedo nigra) are considered to be disturbance indicators (Coombs 1970). Annual Herbaceous Communities The annual herbaceous type is a con- glomeration of several terrestrial commu- nities that occupy waste places around the lake. These areas often have little in common and exhibit high variability in environment and species composition. Because of great en- vironmental variability and regular disturb- ance, such as along beaches, seasonally in- undated islands, and areas heavily impacted by the activities of man, the communities of- ten remain in early serai stages of succession. This is evidenced by the fact that most of the dominant species (Table 9) are of the annual life form, a life-style that permits plants to complete their life cycle in a few months. Since variation is great and conditions change from year to vear, patterns in species dominance also fluctuate annually. Stability will only come to these communities as envi- ronmental predictability increases. 1981 Utah Lake Monograph 75 Ecological Relationships Total Cover Total cover in the communities surround- ing Utah Lake varies from 9.8 percent in the pondweed sites to 76.6 percent in the Grass- Rish-sedge meadows (Table 3). Observed dif- ferences appear to be related to variations in moisture (Fig. 3). As seen in Figure 3, the largest cover values occur midway along the moisture gradient in communities that tend to exhibit the most favorable soil moisture re- gimes. When there is either too much mois- ture (year-round inundation) or too little moisture (dry upland sites), fewer plants ap- pear to perform well, thus lowering cover values in these areas. Asexual Reproduction As previously suggested, much of the sub- community variation with the aquatic and semiaquatic communities of Utah Lake can be related to asexual reproduction by domi- nant species. This seems especially true in those communities that are continuously or seasonally inundated for long periods. Figure 4 illustrates this relationship. Communities having dominant species that reproduce asex- ually are also those communities common to the wet end of the moisture gradient. This being the case, it appears that those habitats with the most uniform moisture conditions tend to select for species capable of asexual reproduction and against species incapable of such reproduction methods. Intraconirnunity Similarity Earlier in this paper reference has been made of the subcommunity (within) varia- tions in each of the seven major community types. Such internal variations can be mea- sured with similarity indices. I have com- puted a similarity index matrix (Runzicka 1958) utilizing all stands in each community. Thus, the similarity of each stand with all other stands of a commimity is obtained. All similarity indices in each community matrix is finally averaged to obtain a mean and stan- dard deviation for internal similarity of each community type. The larger the value the more internally similar is the community; conversely, the lower the value the greater the internal variability. Variation in in- tracommunity similarity is plotted against variation in available moisture for growth in Figure 5. Intracommunity variation is seen to increase as moisture variability increases. This indicates that as habitat predictability decreases, the composition of communities occupying such habitats also becomes more variable and less recognizable as distinct en- tities. Life Forms The relationship of plant life forms to envi- ronmental factors has been the concern of 20. MOISTURE INDEX WET DRY Fig. 3. Total living cover in the Utah Lake commu- nities in relationship to changing moisture conditions. < i o 111 ^ a. is *°- 25 o " o MOISTURE INDEX WET DRY Fig. 4. Importance of asexual reproducing species in the Utah Lake communities as moisture becomes less available. 76 Great Basin Naturalist Memoirs No. 5 ^ 2.0 < < i 1.0 .2 MOISTURE VARIATION Fig. 5. Variation in internal community similarity as moisture variation increases. 30_ 3 INDEX Fig. nities MOISTURE WET DRY 7. Importance of sedges in Utah Lake commu- n relationship to changing moisture conditions. MOISTURE INDEX WET DRY the Utah Lake com- Fig. 6. Importance of grasses munities in relation.ship to changing moisture condi- tions. ecologists for many years. The life form con- cept was useful in this paper in delimiting community types (i.e., grass-ru.sh-sedge mead- ows, lowland woody communities, or annual herbaceous communities). The concept also helps relate environmental pattern to plant response in the habitat complex of Utah Lake (Table 3, Figs. 6-10). The data demonstrate that some of the life form classes exhibit rather distinct responses to moisture patterns around the lake. Grasses, for example, do best o iti £ 20_ MOISTURE INDEX WET DRY Fig. 8. Importance of annuals in the communities of Utah Lake in relationship to changing moisture condi- tions. in habitats with moisture regimes midway along the gradient (Fig. 6). In contrast, the sedges are most abundant at the higher mois- ture levels (Fig. 7). Annuals reach their great- est importance in the driest habitats (Fig. 8). With respect to annuals, the relation.ships de- picted by Figures 9 and 10 are also of inter- est. As shown, the annual life form does espe- cially well in habitats that are open, low in cover, and support a good deal of exposed .soil. In such areas, interspecific competition 1981 Utah Lake Monograph 77 80- 60_ • / 40 _ / / • 20_ >•' ^ 1 1 20 40 60 80 7, EXPOSED SURFACE AREA Fig. 9. Importance of annuals in the communities of Utah Lake in relationship to percent exposed surface area. 60 7. TOTAL COVER Fig. 10. Importance of annuals in the communities of Utah Lake in relationship to total living cover. is low, thus giving species which by life-style must complete the life cycle in one season the maximum opportunity to do so. Introduced Exotics Species distribution patterns vary greatly in nature; however, in many cases the range of a species tends to be confined to a well- defined geographical region. Should a species jump the barriers confining it to its original range and invade another ecosystem else- TIME IN YEARS Fig. 11. Increased importance of introduced species in Utah Lake flora since the early 1800s. where, it becomes a foreign element in that community and is classed as an introduced or exotic species. Historically, many such spe- cies have entered the vegetation surrounding Utah Lake (Fig. 11). Cottam (1926) com- pleted the first real quantitative work on the vegetation of Utah Lake. He listed 333 spe- cies in the flora, 67 of which (20 percent) were introduced. Coombs (1970) quan- titatively studied the same area. He observed 305 species in the flora, 84 of which were in- troduced (27 percent). Ecologically, introduced species may (1) invade native ecosystems and cause unex- pected consequences of a harmful or dis- ruptive nature, (2) invade and increase the complexity of existent ecosystems and be- come useful (nondisruptive) components of such communities, (3) become marginally es- tablished and exhibit no apparent effect on the original system, or (4) fail to become es- tablished. In the case of the communities around Utah Lake, one can find examples of species that fill all the above categories. However, only a few species (i.e., Tamarix ramosissima, Elaeagnus angustifolia, Bromus tectorum, Trifolium hybridum, Atriplex hor- tensis. Polygonum lapathi folium, and Malva neglecta, etc.) have become major influences in these natural communities. If the distribu- tion patterns of the introduced species of the communities studied in the interest of habitat 78 Great Basin Naturalist Memoirs No. 5 Table 10. Plant families contributing the majority of species to the flora of Utah Lake. Family Percent of speci u 40 Asteraceae Poaceae Cyperaceae Chenopodiaceae Cruciferae Leguminosae Polygonaceae Rosaceae Labiatae Salicaceae Scrophulariaceae Onagraceae Total 16.7 14.5 6.3 5.9 5.9 3.9 2.9 2.9 2.5 2.2 2.2 2.0 67.9 MOISTURE VARIABILITY Fig. 12. Importance of introduced species in the com- munities of Utah Lake as moisture variability increases. 30- .5 .1jO VARIATION IN INTERNAL SIMILARITY OF COMMUNITY TYPES Fig. 13. Importance of introduced species in the Utah Lake communities as internal community similarity in- creases. conditions surrounding the lake are consid- ered, two important relationships emerge (Figs. 12 and 13). First, as shown in Figure 12, the introduced species reach their great- est development in those habitats that show the greatest variability in moisture (the most unpredictable environments); and second (Fig. 13), those communities having the greatest internal variation in composition tend to be the most easily invaded. Undoubt- edly, such communities have structural gaps that allow a species entering from the outside to become established and compete success- fully. These gaps would almost certainly arise as a result of interaction between moisture variability and the resultant effect it has on internal community structure. Floristic Relationships A total of 483 species of vascular plants, representing 275 genera, and 74 families was observed and/ or found recorded as belonging to the plant communities of Utah Lake. Of these, 67.9 percent belonged to 12 plant fam- ilies (Table 10). The ecological or phyto- geographical significance of the dominance of these families (Table 10) is not known, but further investigations along such lines should hold great interest. ACERACEAE Acer grandidentatum Nutt. Acer negundo L. AlZOACEAE Sesuvium verrucosum Raf. Alismataceae Alisma triviale Pursh Sagittaria cuneata Sheld. Amaranthaceae Amaranthus graecizans L. Amarantlnis retro flextis L. Anacardiaceae Rhus radicans L. Rhus trilohata Nutt. 1981 Utah Lake Monograph 79 Apocynaceae Apoctjninn cdnncihinimi L. var. glahcrriimttn A. DC. ASCLEPIADACEAE Asclepias incarnata L. Asck'pias speciosa Torr. ASTERACEAE Achillea millefolium L. Ambrosia artemisiifolia L. Ambrosia psilostachya DC. Antheinis cotula L. Arctium minus Schk. Artemisia absinthium L. Artemisia dracunctilus L. Artemisia hidoviciana Nutt. Artemisia spinescens D.C. Eaton Artemisia tridentata Nutt. Aster brachyactis Blake Aster chilensis Nees ssp. adscendens (Lindl.) Cronq. Aster eatonii (A. Gray) Howell Aster frondosus (Nutt.) Torr. & Gray Aster perelegans A. Nels. & Macbr. Balsamorhiza hookeri Nutt. Bidens cernua L. Bidens frondosa L. Chaenactis douglasii H. & A. Chrysopsis villosa (Pursh) Nutt. var. foliosa (Nutt.) D.C. Eaton Chrysothamnus nauseosus (Pall.) Britt. Chrysothamnus viscidiflorus (Hook.) Nutt. Cichorium intybiis L. Cirsium arvense (L.) Scop. Cirisium foliosum (Hook.) DC. Cirsium undulatum (Nutt.) Spreng. Cirsium vulgare (Savi) Airy- Shaw Conyza candensis (L.) Cronq. Crepis modocensis Greene Crepis runcinata (James) Torr. & Gray Erigeron bellidiastrum var. typicus Cronq. Erigeron divergens Torr. & Gray Erigeron glabellus Nutt. Erigeron lonchophyllus Hook. Eupatorium maculatum L. Franseria acanthicarpa (Hook.) Gov. Gnapluiliimi chilense Spreng. Gnaphalium patustre Nutt. Grendelia squarrosa (Pursh) Donal Haplopappus lanceolatus (Hook.) Torr. & Gray Haplopappiis watsoni A. Gray Helenium autumnale D.C. Eaton Helianthus annuus L. Helianthus nuttallii Torr. & Gray Helianthus petiolaris Nutt. Hieracium gracile Hook. Hymenoxys acaulis (Pursh) Parker Inula helenium L. Iva axillaris Pursh Iva xanthifolia Nutt. Lactuca pulchella (Pursh) DC. Lactuca scariola L. Laphamia stansburii A. Gray iMyia glandulosa (Hook.) Hook. & Am. Lygodesmia grandiflora (Nutt.) Torr. & Gray Machaeranthera tanacetifolia (HBK.) Ne.ss Matricaria matricarioides (Less.) Porter Scnccio lujdrophilus Nutt. Senecio uintahcnsis (A. Nels.) Greene Solidago canadensis L. Solidago occidentalis (Nutt.) Torr. & Gray Sonchus arvensis L. Sonchus asper (L.) Hill Stephanomeria pauciflora (Torr.) Nutt. Tanacetum vtdgare L. Taraxacum officinale Weber Tctradymia glabrafa A. Gray Tctradyniid spinosa Hook. & Arn. Townscndia florifcr (Hook.) A. Gray Townsendia strigosa Nutt. Tragopogon dubius Scop. Tragopogon porrifolius L. Viguiera ciliata (Robins. & Greenm.) Blake Viguiera multiflora (Nutt.) Blake Wyethia amplexicaulis (Nutt.) Nutt. Xanthium strumarium L. Xanthocephalum sarothrae (Pursh) Shinners Betulaceae Alnus tenuifolia Nutt. Betula occidentalis Hook. Boraginaceae Cryptantha flavoculata (A. Nels.) Payson Cryptantha nana (Eastw.) Payson Cynoglossum officinalis L. Heliotropium curassavicum L. Lappida redowskii (Hornem.) Greene Lithospennum ruderale Doug, ex Lehm. Plagiobothrys scouleri (Hook. & Arn.) I.M. Cactaceae Echinocactus simpsonii Engelm. Echinocereus triglochidiatus Engelm. var. melana- canthus (Engelm.) L. Benson Opuntia fragilis (Nutt.) Haw. Opuntia polycantha Haw. Capparidaceae Cleome lutea Hook. Cleome serrulata Pursh Polanisia dodecandra (L.) DC. Caprifoliaceae Lonicera involucrata (Rich.) Banks Caryophyllaceae Cerastium vulgatttm L. Saponaria officinalis L. Spergularia marina (L.) Griseb. Ceratophyllaceae Ceratophyllum demersum L. Chenopodiaceae Allenrolfea occidentalis (S. Wats.) Kuntze Atriplex confertifolia (Torr. & Frem.) S. Wats Atriplex heterosperma Bunge Atriplex hortensis L. 80 Great Basin Naturalist Memoirs No. 5 Atriplex patula var. hastata (L.) A. Gray Atriplex tridentata Kuntze Ceratoides lanata (Pursh) J. T. Howell Chenopodiwn album L. Chenopodium chenopodiodes (L.) Aellen Chenapodium fremontii S. Wats. Chenopodium gigantospennum Aellen Chenopodium glaucum L. Chenopodium leptophyUum Nutt. Chenopodiwn murale L. Chenopodium wat.soni A. Nels. Corispermum viUosum Rydb. Echinopsilon hyssopifolium (Pall.) Moq. Grayia spinosa (Hook.) Moq. Hologeton glomeratus (Bieb.) May. Kochia americana S. Wats. Kochia scoparia (L.) Schard. Monolepis nuttalliana (Schult.) Greene SaUcornia pacifica Standi. Salicornia rubra A. Nels. Salsola iberica Senner & Pan. Sarcobatus venniculatus (Hook.) Torr. Suaeda depressa (Pursh) S. Wats. Suaeda fruticosa (L.) Forsk. Suaeda nigra (Raf.) J. F. Macbride Suaeda occidentalis S. Wats. CONVOLVULACEAE Convolvulus arvensis L. Convolvulus sepium L. Cressa truxillensis H.B.K. Cuscuta salina Engelm. CORNACEAE Cornus stolonifera Michx. Cruciferae Arabis glabra (L.) Bernh. Arabis holboellii Hornem. Brassica campestris L. Brassica kaber (D.C.) Wheeler var. pinnatifida Brassica nigra (L.) Koch Camelina microcarpa Andrz. Capsella bursa-pastoris (L.) Medic. Cardamine pennsylvanica Muhl. ex Willd. Cardaria draba (L.) Desv. Conringia orientalis (L.) Diimort Descurainia pinnata (Walt.) Britt. Descurainia sophia (L.) Webb. Erysimum capitatum (Dougl.) Greene Erysimum iiicon.spicuum (S. Wats.) Mac M. Erysimum rcpandum L. Hutchinsia procumbens (L.) Desv. Lepidium densiflorum Schrad. Lcpidium densiflorum var. ramosum (A. Nels.) Thel Lepidium moutdiuim Niitt. Lepidium perfoliatum L. Lepidium virginicum L. Malcolmia africana (L.) R. Br. Nasturtium officinale R. Br. in Ait. Physaria australis (Payson) Rollins Rorippa islandica (oed.) Borbas Sisymbrium altissimum L. Stdnleyella wrightii (A. Gray) Rydb. Streptanthus eordatus Nutt. ex Torr. & Gray Tltehjpodium sagittatum (Nutt.) Endl. Cupressaceae Juniperus osteosperma (Torr.) Little Cyperaceae Carex aurea Nutt. Carex aquatilis Wahl. Carex atherodes Spreng. Carex lanuginosa Michx. Carex nebraskensis Dewey Carex petasata Dewey Carex praegracilis W. Boott. Cyperus erythrorhizos Muhl. Cyperus strigosus L. Eleocharis acicularis (L.) Roem. & Schult. Eleocharis bolanderi A. Gray Eleocharis palustris (L.) Roemer & Scultes Eleocharis parvula (Roem. and Schult.) Link. var. col- oradensis (Britton) Beetle Eleocharis pauciflora (Lightf.) Link. Eleocharis rostellata Torr. Fimbristylis spadicea (L.) Vahl. Scirpus acutus Muhl. Scirpus americanus Pers. Scirpus lacustris L. Scirpus maritimus L. Scirpus microcarptis Presl. Scirpus pallidus (Britton) Fernald Scirpus validus Vahl. Dipsacaceae Dipsacus sylvestris Huds. Elaeagnaceae Elaeagnus angustifolia L. Shepherdia argentea (Pursh) Nutt. Ephedraceae Ephedra viridis Coville Equisetaceae Equisetum ancnse L. Equisettim kansunum Schaffn. Equisetum hnvigatum \. Br. Equisetum palustre L. EuPHORBlACEAE Euphorbia glyptospenna Engelm. ex Emory Euphorbia serpyllifolia Pers. FUMARIACEAE Corydalis aurea Willd. Gentian ACEAE Centaurium exaliaium (Griseb.) Wight Geraniaceae Erodium cicutarium (L.) L'Her. Haloracac:eae Hippurus vulgaris L. Myrioplu/tlum spicatum L. 1981 Utah Lake MoN()(;aAPn 81 HvDlUXIlAKirACE.VK Elodcd caiuKlcnsis Midix. IkIDAC KAK Susynnchiiun iKilopluliiiii C.reene JlNCACEAK Jiinciis hdlticus W'illd. ]uu(us htifoiiiiis L. Jumus cnsijolius Wikstr Juruus lou'^istylis Torr. Jiiiuiis tonciji Coville JUNCAGINACEAE Triglochin mahtiina L. Labiatae Lamium mnplexicaulc L. Lijroptis (imcriconus Miihl. ex Bart. Ltjcopiis Iticidus Turcz. Marrubium vulgare L. Mentha arvensis L. Mentha spicata L. Mohlaiira parviflora (Niitt.) Britt. Nepcta cataria L. Stachys pahistris L. Teucrium canadense L. var. occidentale (A. Gray) McClintock & Epling Leguminosae Astragahis argophyUus Nutt. var. argophyUus Astragahis heckwethii Torr. & Gray Astragahis canadensis L. Astragahis convallarius Greene Astragahis oophorus S. Wats. Astriigahts utahensis (Torr.) Torr. & Gray Ghjcyrrhiza lepidota Pursh Hedysanim boreale Nutt. Lathyrus brachycahjx Rydb. Mcdicago hiptihna L. Mcdicago sativa L. Mehlottis alba Descr. Mehlotiis officinahs (L.) Lam. Robmia pseudo-acacia L. Thcnnopsis montana Nutt. Trifohum hyhridum L. Trifohiini pratense L. Trifohum repens L. Vicia americana Muhl. var. minor Hook. Lemnaceae Lemna minor L. Lemna trisulca L. Lemna valdiviana Phil Spirodela polyrliiza (L.) Schleid. Lentibulariaceae Utricularia minor L. Liliaceae AUiiim acuminatum Hook. A.^)aragus officinahs L. Smilacina stellata (L.) Desf. LOASACIEAE Mentzrha iilbirauhs Dougl. ex Hook. Mentzcha decapetala (Pursh) Urb. & Gilg. Mentzcha lacvicauhs (Dougl.) Torr. & Gray Mentzeha niultifhra (Nutt.) \. Gray Lythraceae Lythrum sahcaria L. Malvaceae Ahhaea rosea Cav. Muha ncgU'cta Wallr. Sida ludcrarcd (Dougl.) Torr. Sidalcca ncomcxicana A. Grey Sidalcea oregana (Nutt.) A. Gray Sphaeralcea coccinea (Pursh) Rydb. Sphaeralcea grossiilariaefolia (H. & A.) Rydb. Sphaeralcea munroana (Dougl.) Spach Moraceae Morus rubra L. Nyctaginaceae Abronia salsa Rydb. Nymphaeceae NupJiar pohjsepahtm Engelm. Oleaceae Fraxinus vehitina Torr. Onagraceae Epilobium adenocaulon Hausskn. Epilobium paniculatum Nutt. ex Torr. & Gray Gaura parviflora Dougl. Oenothera ahjssoides Hook. & .\rn. Oenothera caespitosa Nutt. Oenothera hookeri Torr. & Gray Oenothera latifoha (Rydb.) Munz Oenothera minor (A. Nels.) Munz Oenothera paUida Lindl. Oenothera scapoidea Torr. & Gray ssp. utahensis Raven Orchidaceae Cypripedium calceohis L. var. pubescens (Willd.) Cornell Epipactis gigantea Dougl. Spiranthes romanzoffiana Cham. & Schl. Orobanchaceae Orobanche nndtiflora Nutt. Papaveraceae Argemone munita Dur. and Hilg. Plantaginaceae Plantago lanceolata L. Plantago major L. Plantago patagonica Jacq. POACEAE Agropyron cristatum (L.) Gaertn. Agropijron dasystachyum Scribn. (Hook.) Agropyron elongatum (Host.) Beauv. 82 Great Basin Naturalist Memoirs No. 5 Agropyron intermedium (Host) Beauv. Agropyron repens (L.) Beauv. Agropyron smithii Rydb. Agropyron spicatum (Pursh) Scribn. & Smith Agropyron trachycaulum (Link) Malte. Agrostis semiverticillata (Forsk.) Agrostis stolonifera L. Alopecurus aequalis Sobol. Avena fattia L. Avena sativa L. Beckmannia syzigachne (Steud.) Fern. Bromus commutatus Schrad. Bromus inermis Leyss. Bromus tectonim L. Calamagrostis canadensis (Michx.) Beauv. Calamagrostis neglecta (Ehrh.) Gaertn. Mey & Schreb. Catabrosa aquatica (L.) Beauv. Cenchnis tribidoides L. Dactylis glomerata L. Deschampsia caespitosa (L.) Beauv. Distichlis spicata (L.) Green Echinochloa crusgalli (L.) Beauv. Elymus canadensis L. Michx. Elymus cinereus Scribn. & Merr. Elymus simplex Scribn. & Wilhams Elymus tritiocides Buckl. Elymus virginicus L. var. submuticus Hook. Eragrostis cilianensis (All.) Mosher Eragrostis hypnoides (Lam.) Britton, Sterns, & Poggenb. Eragrostis orcuttiana Vasey Festuca pratensis Huds. Glyceria grandis S. Wats. Hordeum brachyantherum Nevski Hordeum jiibatnm L. Hordeum leporinum Link. Leersia oryzoides (L.) Swantz Leptochloa fascicularis (Lam.) A. Gray Lolium multiflorum Lam. Muhlenbergia asperifolia (Nees & Meyen) Parodi Oryzopsis hymenoides (R. & S.) Riker Panicum capillare L. Panicum capillare L. var. occidentale Rydb. Phalaris arundinacca L. Phleum pratense L. Phragmities australis (Cav.) Trin. ex Stendel Poa annua L. Poa navadensis Vasey ex Scribn. Poa pratensis L. Polypogon monspeliensis (L.) Desf. Puccinellia nuttaUiana (J. A. Schuites) ,\.S. Hitchc. Sclerochloa dura (L.) Beauv. Secale cereale L. Setaria glauca (L.) Beauv. Setaria viridis (L.) Beauv. Sitanion hystrix (Nutt.) J. G. Smith Sitanion jubafum J. G. Smitli Hparliua gracilis Trin. Sphenopholis obtusata (Miciix.) Scriiin. Sporobolus airoides (Torn) Torr. Sporoholtis asper (Michx.) Kunth Sporobolus cryptandrus (Torr.) A. Gray Stipa coinata Trin. & Rupr. Triticum acstivum L. Vulpia octoflora (Walter) Rydb. POLEMONIACEAE Collomia linearis Nutt. Gilia aggregata (Pursh) Spreng. Gilia inconspicua (Smith) Sweet Gilia leptomeria A. Gray Gilia tenerrima A. Gray Phlox austromontana Goville Phlox longifolia Nutt. Polemonium micranthum Benth. Polemonium occidentale Greene POLYGONACEAE Eriogonum effusum Nutt. Eriogonum racemosum Nutt. Eriogonum umbellatum Torr. Polygonum amphibium L. Polygonum aviculare L. Polygonum coccineiwi Muhl. ex Willd. Polygonum convolvulus L. Polygonum lapathifolium L. Polygonum pennsylvanicum L. Polygonum persicaria L. Polygonum ramosissimum Michx. Rumex crispus L. Rumex fueginus Phil. Rumex venosus Pursh PORTULACACEAE Portulaca oleracea L. POTAMOGETONACEAE Potamogeton crispus L. Potomogeton filiformis Pars. Potamogeton foliosus Raf. Potamogeton nodosus Poir. ex Lam. Potamogeton pectinatus L. Potamogeton praelongus Wulf. Primulaceae Dodecatheon pulchellum (Raf.) Merrill Glaux maritima L. Steironeyna ciliatum (L.) Raf. Ranunculaceae Delphinium andersoni \. Gray Ranunculus acris L. Ranunculus acjuatilis L. capdkiceus (Thuill.) DC. Ranunculus circinatus Sibth. Ranunculus cymbalaria Pursh Rauuncuhis macounii Britton Ranunculus orcogcnes Greene Ranunculus tcsticulatus Grantz Rosaceae Amelanchicr alnifolia (Nutt.) Nutt. Amelanchicr utalicnsis Koehne Cowania mcxicana D. Don Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. Potentilla anserina L. Potentilla biennis Greene Potentilla ghmdutosa Lindl. Potentilla gracilis Dougl. var. clmcri (Rydb.) Jeps. Potentilla paradoxa Nutt. Primus americana Marsh Prunus virginiana L. var. mclanocarpa {\. Nels.) Sarg. 1981 Utah Lake Monograph 83 Puishia tmlcntata (Pursh) DC. Rosa nutkana Presl. Rosa woodsii Lindl. RUBIACKAE Galium trifkhiiii L. Rl'PPIACEAE Rttppia maritima L. Salicaceae Populus alba L. Populus angustifolia James Populus dcltoides Bartr. Populus fremontii S. Wats. Poptilus nigra L. var. italica Muenchh. Populus trichocarpa Torr. & Gray Salix amiigdaloides Anders. Sa/i.v cxigua Nutt. Salix fragilis L. Salix lasiandra Benth. Salix rigida Miihl. Salviniaceae Azolla caroliniana Willd. Salvinia rotundifolia Willd. Santalaceae Comandra pallida A. DC. Saxifragaceae Heuchera pawifolia Niitt. ex Torr. & Gray Ribes aureiim Pursh Scrophulariaceae Castilleja chromosa A. Nels. Castilleja exilis A. Nels. Castilleja minor (A. Gray) A. Gray Collinsia grandiflora Dougl. Cordijlanthus canescens A. Gray Mimulus glabratus HBK Mimidiis guttatus DC. Penstemon humilis Nutt. ex A. Gray Verbascum thapsus L. Veronica americana Schwein Veronica anagallis-aquatica L. Veronica hederaefolia L. Veronica peregrina L. SOLANACEAE Lijcium halimifolium Mill. Physalis longifolia Nutt. Solanum dulcamara L. Sokinum nigrwn L. Solanum triflorum Nutt. Sparganiaceae Sparganium emersum Rehmann Sparganium eiirycarpum Engelm. Tamaricaceae Tamarix ramosissima Ledeb. Thypaceae Typha angustifolia L. Typha latifolia L. Ulmaceae Celtis reticulata Torr. Ulinus americana L. Vhnus puinila L. Umbelliferae Berulu erecta (Huds.) Coville Cicuta douglasii (DC>'.) Coult. & Itose Coniuni maculatum L. Pastinaca sativa L. Slum suave Walt. Urticaceae Urtica dioica L. var procera (Muhl.) Wedd. Urtica serra Bhune Verbenaceae Verbena bracteata Lag. and Rodr. Verbena hastata L. Verbena stricta Vent. Violaceae Viola nephrophylla Greene Zannichelliaceae Zannichellia palustris L. Zygophyllaceae Tribulus terrestris L. Species included in the literature as being present in the Utah Lake flora but for which there is not any evidence that such is the case. Amaranthus lividus L. Camelina sativa (L.) Crantz. Carex apcrta Boott. Cenchrus tribuloides L. Erigeron anniius (L.) Pers. Gnaphalium occidentalis Nutt. Lepidium ramosissimum A. Nels. Mirabilis linearis (Pursh) Heimerl. Sagittaria graminea Michx. Scirpus nebraskensis L. Literature Cited Arnold, B. B. 1960. Life history notes on the walleye, Stizo stedion vitreum vitreum Mitchell, in a tur- bid water, Utah Lake, Utah. Utah Fish and Game Department. Federal Aid Project F-4-r-5 Job T. 107 pp. Barnett, B. 1964. An ecological study of waterfowl hab- itat at Powell's Slough, Utah Lake. Unpublished thesis, Brighani Young Univ. 45 pp. Beck, D. E. 1942. Life history notes on the California gull, No. 1 Great Basin Nat. 3:91-108. Bessey, G. E. 1960. The aquatic plants of central Utah and their distribution. Unpublished thesis, Brig- ham Young Univ. 85 pp. Brown, D. 1958. Methods of surveying and measuring vegetation. Commonwealth Agricultural Burlaux Farnham Royal, Bucks, England. 223 pp. 84 Great Basin Naturalist Memoirs No. 5 Chavez, F. A., and T. J. Warner. 1976. The Domin- guez-Escalante journal. Brigham Young Univ. Press, Provo, Utah. 203 pp. Christensen, E. M. 1965. Ecological observations of peach-leaf willow in central Utah. Proc. Utah Acad. Sci., Arts, Lett. 43:85-88. Coombs, R. E. 1970. Aquatic and semi-aquatic plant communities of Utah Lake. Unpublished dis- sertation, Brigham Young Univ. 252 pp. Cottam, W. p. 1926. An ecological study of the flora of Utah Lake, Utah. Unpublished dissertation, Univ. Chicago, Chicago, Illinois. 137 pp. Croquist, a., et al. 1977. Intermountain flora. Vol. 6. Columbia Univ. Press, New York. 584 pp. Foster, R. H. 1968. Distribution of the major plant communities in Utah. Unpubli.shed dissertation, Brigham Young Univ. 124 pp. Holmgren, A. H., and J. L. Reveal. 1966. Checklist of the vascular plants of the Intermountain Region. U.S. Forest Service research paper INT-.32. Inter- mountain Forest and Range Experiment Station, U.S. Forest Service, U.S. Department of Agricul- ture, Ogden, Utah. 160 pp. Lawler, R. E. 1960. Observations on the life history of channel catfish, Ictahinis puncfatiis Rafinesque, in Utah Lake. Unpublished thesis, Utah State Univ., Logan. 69 pp. LiECHTY, W. R. 1952. A preliminary study of the genus Carex in Utah County, Utah. Unpublished thesis, Brigham Young Univ. 105 pp. MacArthur, R. H. 1972. Geographical ecology-patterns in the distribution of species. Harper and Row, New York. 269 pp. Murphy, J. R. 1951. Ecology of passerine birds winter- ing at Utah Lake. Unpublished thesis, Brigham Young Univ. 63 pp. Phillips, E. A. 19.59. Methods of vegetation studv. Holt, Rinehart and Winston, New York. 107 pp. RuzicKA, M. 1958. Anwendung Mathematisch- Statistichae Methoden in der geobotanik (Syn- thetische bearbeitung von aufnahmen). Biologia, Bratisl. 13:647-661. Skougard, M. G. 1976. Vegetational response to three environmental gradients in a salt plava near Goshen, Utah County, Utah. Unpublished thesis, Brigham Young Univ. 75 pp. Sneath, p. H. A., and R. R. Sokal. Numerical tax- onomy. W. H. Freeman and Company, San Fran- cisco. 573 pp. Wakefield, J. H. 1933. A study of the plant ecology of Salt Lake and Utah Valleys before the Mormon immigration. Unpublished thesis, Brigham Young Univ. 54 pp. 1937. Transect study of Utah Lake shore line from 19.30 to 1936. Proc. Utah Acad. Sci., Arts, Lett. 14:.39-40. Warner, J. H., and K. T. Harper. 1972. Understory characteristics related to site quality for aspen in Utah. Brigham Young Univ. Sci. Bull., Biol. Ser. 16(2): 1-20. Weic;ht, K. E. 1928. The distribution, taxonomy and ecology of the genus Salix of Utah County, Utah. Unpublished thesis, Brigham Young Univ. 72 pp. Welsh, S. L., and G. Moore. 1973. Utah plants. Tracheophyta. Brigham Young Univ. Press, Pro- vo. Utah. 474 pp. White, D. A. 1963. Ecology of .summer aquatic in- vertebrate populations in a marsh area of Utah Lake. Unpublished thesis, Brigham Young Univ. 36 pp. PHYTOPLANKTON OF UTAH LAKE Samuel R. Rushforth,^ Larry L. St. Clair,' Judith A. (Crimes,' and Mark C. Whiting' Abstract.— The plankton flora of Utah Lake includes a total of 295 species to date. This high number of taxa indicates greater diversity than previously suspected. Together with water chemical data it leads us to conclude that Utah Lake is a slightly saline eutrophic system. This conclusion is further substantiated by quantitative data which show very high levels of productivity during late simimer and early fall. slightly through Utah Lake is a shallow, eutrophic, saline desert lake located in central Utah (Map 1). The deepest portion of the lake is no more than 4.2 m and the average depth is 2.8 m (Bingham 1974). The lake covers an area of 388 km2 (Brown 1968). The water is highly turbid with Secchi di.sk readings aver- aging 24 cm and ranging from less than 12 to 50 cm. The lake is often classified as highly eutrophic due to the turbidity and dense al- gal blooms that occur essentially every year in the late summer and early fall. The lake basin receives inflow from nu- merous mineral springs within and around the periphery of the lake. As a result, the wa- ter has a high carbonate and sulfate content. The total dissolved solids in the lake varied between 795 and 1650 mg/1 from 1961 to 1978. At the present conductivity level (aver- age 1400 jum) of the lake and assuming the same ions are pre.sent, the total dissolved sol- ids range from 700 to 1000 mg/1 during typi- cal inflow years and lake levels. Lakes having between 1,000 and 3,000 mg/1 of dissolved solids are described by the U.S. Geological Survey (Hem 1970) as being slightly saline. Preliminary studies of zooplankton were conducted by Tanner (1931) and Hunt (1940), but little significant research has been done since. Likewise, few significant studies of the phytoplankton have been done. Harding (1970, 1971) published two algal lists in which he identified several phytoplankters as being present in the lake. However, his lists are incomplete, and particularly ignore the Bacillariophyta (diatoms). This stvidy provides a comprehensive list of all algae collected from the water column 1978, together with descriptions of the major algal species present in Utah Lake. We are aware that many of these species, particularly many of the diatoms, are not true plankters. Even so, they represent im- portant members of the floating algal assem- blage and thus are reported herein. Mi Phytoplankton samples were collected at regular intervals during the summer of 1974 at 14 stations along three permanent tran- sects (Map 1). The transects were chosen to represent three supposed subenvironments within the lake. Stations were established at approximately equal intervals along the transects. Each station was marked with buoys, and shore triangulation points were recorded so that the point could be relocated on each successive sampling date. The north- ern or Geneva transect ran west from the spillway of the settling pond of United States Steel's Geneva Works. It consisted of 5 sta- tions. The middle or Provo Boat Harbor transect also had 5 stations. It ran west from a point just south of the mouth of Provo Riv er and north of Provo Bay. The southern or Goshen Bay transect, with only 4 stations, ran west from Ludlow's sheep barns near Lincoln Beach. Samples were collected every nine days from 4 June 1974 to 15 August 1974. Sam- pling was always done in the morning in or- der to minimize diurnal variability. In addi- tion, samples were collected on a less intensive basis during the spring and summer months of 1975 and 1976 and again with 'Department of Botany and Range Science, Brigham Young University, Provo, Utah 84602. 'Present address: Department of Botany, Oregon State University, Corvallis, Oregon 97330. 85 86 Great Basin Naturalist Memoirs No. 5 3 ^ S ^ S (TS 1981 Utah Lake Monograph 87 greater intensity during the summer and fall of 1978. The phytoplankton was sampled by pour- ing known volumes of water through a 64 jum mesh net. The water was dipped from the lake with a 10-liter bucket. The amount of water poured through the net varied as the summer progressed because the amount of al- gae in a given volume of water increased during bloom periods. In most cases, algae were identified and counted immediately upon returning to the laboratory, but in all cases within 48 hours of collection. Laboratory analysis consisted of identi- fying and counting the algae present in phytoplankton samples. Algal samples were subsampled, the organisms present were identified to species, and the frequency of each organism was recorded. Components of the phytoplankton were first counted in Pal- mer coimting cells at 400X and the numbers of organisms in the original lake water were calculated by multiplication factors. Since di- atoms cannot usually be identified to species in wet moimt slides, permanent diatom slides were made using Naphrax mounting medium and standard oxidation methods (St. Clair and Rushforth 1976). The diatoms were counted and the relative frequency of each species was calculated. Results A total of 295 phytoplankters has been identified from Utah Lake (Table 1). Species described below represent some of those most commonly encountered during our stud- ies. Each is given a brief description and a summary of collection data. In addition, a reference to a complete description of the or- ganism is provided. Division: Chlorophyta Order: Volvocales Carteria stellifera Nygaard (Fig. 1). Plant unicellular; cells spherical to subspherical with slight apical papilla from which the four flagella arise, 10-20 jum in diameter, 12.5-22.5 jum long (Thienemann 1961:95). Abundant at the mouth of the Provo River throughout the summer months and occasion- ally important locally in other parts of the lake. Table 1. Phylogeiietic list of algae collected from the water column in Utah Lake 1974-1978. Chlorophyta C;hlorophyceae Volvocales Chlamydomonadaceae Carteria cordiformis (Carter) Dill Carteria klebsii (Dang.) Francd em. Troitzkaja Carteria stellifera Nygaard Chlamydomonas altera Skuja Chlamydomonas globosa Snow Chlamijdornonas polypyrenoideum Prescott Sphaerellopsis aulata (Pascher) Gerloff Phacotaceae Wisloiichiella planctonica Skvortzow Volvocaceae Pandorina morum (Muell.) Bory Pleodorina illinoisensis Kofoid Tetrasporales Palmellaceae Sphaerocystis schroeteri Chodat Ulotrichales Chaetophoraceae Stigeoclonium stagnatile (Hazen) Collins Cladophorales Cladophoraceae Cladophora glomerata (Lemm.) Kuetzing Chlorococcales Micractiniaceae Micractinium piisilhim Fresenius Dictyosphaeriaceae Dictyosphaeriiim ehrenhergianum Naegeli Characiaceae Ankyra judayi (G. M. Smith) Fott. Schroederia setigera (Schroeder) Lemmermann Hydrodictyaceae Pediastrttm boryanum (Turp.) Meneghini Pediastnim duplex Meyen Pediastnim duplex var. brachylobum A. Braun Pediastrum duplex var. clathratum (A. Braun) La- gerheim Pediastnim duplex var. gracilimum West & West Pediastrum simplex (Meyen) Lemmermann Pediastrum simplex var. duodenarium (Bailey) Rabenhorst Pediastrum tetras (Ehr.) Ralfs Pediastrum tetras var. tetraodon (Corda) Hansgirg Coelastraceae Coelastrum microporum Naegeli Oocystaceae Ankistrodesmus convolutus Corda Ankistrodesmus falcatus (Corda) Ralfs Ankistrodesmus falcatus var. mirabilis (West & West) G. S. West Ankistrodesmus falcatus var. stipitatus (Chod.) Lemmermann Closteriopsis longissima var. tropica West & West Kirchncriella lunaris (Kirch.) Moebius Lagerheimia longiseta var. major G. M. Smith Lagerheimia wratislawiensis Schroeder Great Basin Naturalist Memoirs No. 5 Table 1 continued. Table 1 continued. Oocystis borgei Snow Oocystis elliptica W. We.st Oocystis gigas Archer Oocystis gheocystiformis Borge Oocystis lacustris Chodat Oocystis novae-semliae Wille Oocystis parva West & West Oocystis pusilla Hansgirg Oocystis suhmarina Lagerheim Quadrigula lacustris (Chod.) G. M. Smith Selenastrum hihraianum Reinsch Selenastrum gracile Reinsch Selenastrum westii G. M. Smith Treubaria triappendiculata Bernard Scenedesmaceae Actinmtrum hantzschii Lagerheim Actinastrum hantzschii var. fluviatile Schroeder Crucigenia guadrata Morren Crucigenia tetrapedia (Kirch.) West & West Scenedesmus abundans var. brevicauda G. M. Smith Scenedesmus acuminatus (Lagerheim) Chodat Scenedesmus bipiga var. alterans (Reinsch) Hansgirg Scenedesmus bijuga var. flexuosus Lemmermann Scenedesmus dimorphus (Turp.) Kuetzing Scenedesmus longus var. naegelii (de Breb.) G. M. Smith Scenedesmus opoliensis P. Richter Scenedesmus perforatus Lemmermann Scenedesmus quadricauda (Turp.) de Brebisson Scenedesmus quadricauda var. longispina (Chod.) G. M. Smith Zygnematales Desmidaceae Closterium sp. Staurastrum paradoxum Meyen Staurastrum tetracerum Ralfs Chrysophyta Xanthophyceae Tribonematales Tribonemataceae Tribonema bombycinium (C. A. Ag.) Derbes & Solier Chrysophyceae Chrysomonadales Ochromonadaceae Dinohryon bavaricum Imhof Dinobryon divergens Imhof Dinobryon sociale var. americanum (Brunn.) Bachmann Mallomonadaceae Malhmonas acaroides Perty Mallomonas caudata Iwanoff Malhmonas pseudocoronata Prescott Mallomonas tonsurata Tailing Bag illariophyta Bacillariophyceae Biddulphiales Biddulphiaceae Biddulphia laevis Ehrenberg Chaetoceraceae Chaetoceros elmorei Boyer Coscinodiscales Coscinodiscaceae Coscinodiscus lacustris Grunow. Cyclotella antiqua W. Smith Cyclotella bodanica Eulenstein Cyclotella kutzingiana Thwaites Cyclotella meneghiniana Kuetzing Cyclotella ocellata Pantocsek Cyclotella stelligera Cleve and Gnmow Melosira granulata (Ehr.) Ralfs Melosira granulata var. angustissima O. Mueller Melosira italica (Ehr.) Kuetzing Melosira varians Agardh Stephanodiscus astrea (Ehr.) Grunow Stephanodiscus astrea var. minutula (Kuetzing) Grunow Stephanodiscus niagarae Ehrenberg Thalassiosira sp. Fragilariales Fragilariaceae Asterionella formosa Hassall Diatoma tenue Agardh Diatoma tenue var. elongatum Lyngbye Diatoma vulgare Bory Diatoma vulgare var. grande (W. Sm.) Grunow Fragilaria brevistriata Grunow Fragilaria brevistriata var. capitata Heribaud Fragilaria brevistriata var. inflata (Pant.) Hustedt Fragilaria construens (Ehr.) Gnmow Fragilaria construens var. binodis (Ehr.) Grunow Fragilaria construens var. pumila Grunow Fragilaria construens var. venter (Ehr.) Grunow Fragilaria crotonensis Kitton Fragilaria leptostauron (Ehr.) Hustedt Fragilaria vaucheriae (Kuetz.) Petersen Hannaea arciis (Ehr.) Patrick Ophephora martyi Heribaud Synedra capitata Ehrenberg Synedra delicatissima var. angustissima Grunow Synedra fasciculata var. truncata (Grev.) Patrick Synedra mazamaensis Sovereign Synedra rumpens var. familiaris (Kuetz.) Gnmow Synedra rumpens var. fragilarioides Gnmow Synedra rumpens var. scotica (Grunow Synedra tenera W. Smith Synedra ulna (Nitzsch) Ehrenberg Synedra ulna var. contractu Ostrup Eunotiales Eunotiaceae Eunotia arcus var. bidens Grunow Achnanthales Achnanthaceae Achnanthes clevei Grunow Achnanthes deflexa Reimer 1981 Utah Lake Monograph 89 Table 1 toiitiniied. Table 1 continued. Achrumthes exigtia Gninow Achnanthes hauckiana Gninow Achrumthes lanceolata (Breb.) Gninow Achrumthes lanceolata var. duhia Gninow Achrumthes linearis (W. Sm.) Gninow Achrumthes ininutissirna Kuetzing Cocconeis pedicttlus Ehrenberg Cocconeis placenttila var. eughjpta (Ehr.) Cleve Cocconeis placentula var. lineata (Ehr.) Van Heurck Cocconeis diminuta (Pantocsek Rhoicosphenia curvata (Kiietz.) Gninow Naviciilales Naviculaceae Anomoeoneis sphaerophora (Ehr.) Pfitzer Caloneis amphisbaena (Bory) Cleve Cahru'is bacillum (Gnin.) Cleve Caloneis fcnzlioides Cleve-Euler Caloneis schumanniana (Gninow) Cleve Diploneis oblongella (Naegeli ex Kuetz.) Ross Diploneis pseudovalis Hustedt Diploneis smithii var. dilatata (M. Perag.) Boyer Diploneis sniitliii var. pumila (Gnin.) Hustedt Gijrosigma acuminatum (Kiietz.) Rabenhorst Mastogloia elliptica var. danseii (Thwaites) Cleve Navicula amphibola Cleve Navicula arvensis Hustedt Navicula aurora Sovereign Navicula capitata Ehrenberg Navicula capitata var. hungarica (Gnin.) Ross Navicula circumtexta Meist. ex Hustedt Navicula crucicula (W. Sm.) Donk. Navicula cnjptocephala Kuetzing Navicula cryptocephala var. veneta (Kuetz.) Rabenhorst Navicula cuspidata (Kuetz.) Kuetzing Navicula exigua Greg, ex Gninow Navicula exigua var. capitata Patrick Navicula graciloides A. Mayer Navicula lanceolata (Ag.) Kuetzing Navicula menisculus var. upsaliensis (Grun.) Gninow Navicula minima Gninow Navicida minuscula Gninow Navicula ohlonga (Kuetz.) Kuetzing Navicula pelliculosa (Breb. ex Kuetz.) Hilse Navicida pcrcgrina (Ehr.) Kuetzing Navicida piipida Kuetzing Navicula pupula var. rectangularis (Greg.) Gninow Navicula pijgmuca Kuetzing Navicula radiosa Kuetzing Navicula rcinlwrdtii var. elliptica Heribaud Navicula rhyncocephala Kuetzing Navicula salinarum Gninow Navicula salinarum var. intermedia (Grun.) Cleve Navicula scutcUoides W. Sm. ex Gregory Navicula sccreta var. apiculata Patrick Navicula tenelloides Hustedt Navictda tripunctata (Muell.) Bory Navicula tuscula Ehrenberg Navicula viridula (Kuetz.) Kuetzing em. Van Heurck Navicula sp. Neidiimi iridis (Ehr.) C;leve Pinnularia borealis var. rectangularis Carlson Pinnularia brchissonii (Kuetz.) Rabenhorst Pinnularia microstauron (Ehr.) Cleve Pinnularia viridis (Nitzsch) Ehrenberg Pleurosigma australe Gninow Pleurosigma delicatulum W. Smith Scoliopleura peisonis Grunow Stauroneis phoenicentron (Nitzsch.) Ehrenberg Cymbellaceae Amphora coffeiformis (Agardh) Kuetzing Amphora ovalis (Kuetz.) Kuetzing Amphora ovalis var. affinis (Kuetz.) Van Heurck (^r De Toni Amphora perpusilla (Grun.) Grunow Amphora veneta Kuetzing Cijmbella affinis Kuetzing Cijmbella cistula (Ehr.) Kirchner Cijmbella cijmbiforniis Agardh Cijmbella mexicana (Ehr.) Cleve Cijmbella microcephala Grunow Cijmbella minuta var. sdesiaca (Bleisch ex. Rabh.) Reimer Cijndjella muelleri Hustedt Cymbella prostrata (Berk.) Cleve Cijmbella sinuata Gregory Cymbella tumida (Breb. ex Kuetz.) Van Heurck Cymbella tumidula Grunow ex A. Schmidt Cymbella sp. 1 Cymbella sp. 2 Gomphonemaceae Gomphonema angustatum (Kuetz.) Rabenhorst Gomphonema clevei Fricke Gomphonema intricatum Kuetzing Gomphonema olivaccum (Lyngb.) Kuetzing Gomphonema parvulum Kuetzing Gomphonema sphaerophorum Ehrenberg Gomphonema truncatum Ehrenberg Gomphonema ventricosum Greg. Entimoneidaceae Entomoneis alata (Ehr.) Ehrenberg Plagiotropis vitrea (W. Smith) Grunow Epithemiales Epithemiaceae Denticula elegans Kuetzing Denticula elegans f. valida Pedic. Epithemia sorex Kuetzing Epithemia turgida (Ehr.) Kuetzing Epidicniia turgida var. grcmulata (Ehr.) Brun Epithemia adnata (Kuetz.) Brebisson Rhopalodia gihha (Ehr.) O. Mueller Rhopalodia gibba var. ventricosa (Kuetz.) H. and M. Peragallo RJiopalodia gibberula var. protracta Gninow Rhopalodia musculus (Kuetz.) O. Mueller Nitzschiales Nitzschiaceae Bacillaria paradoxa Gmelin Cylindrotheca gracilis (Breb.) Gninow 90 Great Basin Naturalist Memoirs No. 5 Table 1 continued. Table 1 continued. Hantzschia amphioxys (Ehr.) Gninow Hantzschia amphioxys f. capitata O. Mueller Nitzschia aciculoris W. Smith Nitzschia amphibia Gmnow Nitzschia apiculata (Greg.) Grunow Nitzschia communis Rabenhorst Nitzschia dissipata (Kuetz.) Grunow Nitzschia filiformis (W. Smith) Hustedt Nitzschia fonticola Gmnow Nitzschia fnisttdum (Kuetz.) Gnmow Nitzschia hantzschiana Rabenhorst Nitzschia hungarica Gnmow Nitzschia linearis W. Smith Nitzschia longissima var. closterium (W. Smith) Van Heurck Nitzschia ovahs Arnott Nitzschia palea (Kuetz.) W. Smith Nitzschia paleacea Gnmow Nitzschia pennintita Gnmow Nitzschia punctata (W. Sm.) Gnmow Nitzschia sigmoidca (Ehr.) W. Smith Nitzschia tnjhhoneUa Hantzsch Nitzschia tryhlioneUa var. debilis (Arnott) A. Mayer Nitzschia tryhlioneUa var. genuina Gnmow Nitzschia tryhlioneUa var. levidensis (W. Sm.) Gnmow Nitzschia tryhlioneUa var. victoriae Grunow Surirellales Surirellaceae Camplyodiscus hibernicus Ehrenberg Cymatopleura elliptica (Breb.) W. Smith Cymatopletira solea (Breb.) W. Smith Surirella angusta Kuetzing Surirella ovalis Brebi,sson Surirella ovalis var. brightweUii (W. Sm.) Cleve- Euler Surirella ovata Kuetzing Surirella striatula Turpin EUGLENOPHYTA Euglenophyceae Euglenales Euglenaceae Euglena ehrenbergii Klebs Euglena gracilis Klebs Euglena oxyuris Schmarda Euglena proxima Dangeard Lepocinclis salina Fritsch Phacus chloroplastes Prescott Phacus tortus (Lemm.) Skvortzow Strombomonas fluviatilis (Lemm.) Deflandre Trachelomonas crebea Killicott— Deflandre Pyrrophyta Dinophyceae Peridiniales Glenodiniaceae Glenodiniuvi dinobnpnis (Woloszynska) Lind- emann Glenodinium penardiforme (Lindemann) Schiller Certiaceae Ceratium hirundinella (Muell.) Dujardin Cyanophyta Myxophyceae Chroococcales Chroococcaceae Anacystis rupestris (Lyngb.) Drouet & Daily Chroococcus minutus (Kuetz.) Naegeli Gloeocapsa punctata Naegeli Gomphospheria aponina Kuetzing Gomphospheria lacustris Chodat Holopedium irregulare Lagerheim Marssoniella elegans Lemmermann Merismopedia glauca (Ehr.) Naegeli Microcystis aureginosa Kutz. em. Elenkin Microcystis incerta Lemmermann Microcystis protocystis Crow Hormogonales Oscillatoriaceae Lyngbya majusculla Harvey Lyngbya martensiana Meneghini Oscillatoria angustissima West & West Oscillatoria articulata Gardner Oscillatoria subbrevis Schmidle Oscillatoria tenuis Agardh Schizothrix lacustris A. Braun ex Kuetzing Nostocaceae Anabaena flos-aquae (Lyngbye) de Brebisson Anabaena spiroides var. crassa Lemmermann Aphanizomenon flos-aquae (Lemm.) Ralfs Nostoc caeruleum Lyngbye Pandorina morum (Muell.) Bory (Fig. 2). Colony ovate or obovoid, composed of 8-16 cells; cells compactly arranged and enclosed by common gelatinous matrix, compressed with broad anterior end directed outward; chloroplast a single parietal cup; cells about 10 /xm in diameter; colony of 16 cells 29-37.5 jxm in diameter, 38-40 [xm long (Prescott 1962:75). Abundant in plankton from Provo River mouth and Provo Boat Harbor, rare to common in remainder of lake. Small colonies of about eight cells were often almost spheri- cal in shape. Pleodorina iUinoisensis Kofoid (Fig. 5). Colony globose with 16-32 cells, 4 of which are small and vegetative; cells spherical, with 4 to 8 pyrenoids; vegetative cells about 8 jum in diameter; reproductive cells about 15 [xm in diameter (Prescott 1962:77). Rare to abun- dant in plankton samples and especially abundant in samples from Provo River mouth. 1981 Utah Lake Monograph 91 Sphaerellopsis atilata (Pascher) Gerloff (Fig. 3). Plant unicellular and free swimming; cells teardrop shaped, widely rounded poste- riorly and narrowly rounded anteriorly to acute apex, 10-15 jum in diameter, 15-20 jum long; chloroplast cup shaped and filling en- tire cell wall; eye spot red and often visible; sheath hyaline and very wide, often with apical papilla where flagella emerge. Sphae- rellopsis differs from Chlamydomonas by its wide sheaths that narrow anteriorly and are not same shape as protoplast (Thienemann, 1961:452). Abundant in Provo River mouth in July and August. Order: Chlorococcales Dictyospliaeriimi ehrenbergianwn Naegeli (Fig. 4). Colony spherical to ovoid, cells at- tached in groups of twos and fours at ends of very fine filaments; cells spherical to ellip- soid, 3-6 jLim in diameter, 6-10 jum long; chloroplasts 1-2 parietal cups (Prescott 1962:238). Abundant in plankton samples from lake and Provo River mouth in early June, becoming less important in July and August. Oocystis horgei Snow (Fig. 6). Plant uni- cellular or in groups of 2-6 enclosed by old mother cell wall; cells ellipsoid-ovate, with poles broadly rounded and without nodular thickenings; chloroplasts single parietal plates; cells 12-13 jum in diameter, 18-20 jum long; colony of four cells about 38 ju,m in di- ameter (Prescott 1962:243). Often the most common Oocystis in Utah Lake and common in our plankton samples throughout summer. Oocystis lacustris Chodat (Fig. 7). Plant unicellular or a colony of four cells; mother cell ovoid or sometimes flattened at poles, about 10 jum in diameter, 17.5 jitm long; chloroplasts 1-2; colony of four cells about 28/Am long (Prescott 1962:245). Often com- mon in plankton samples throughout lake. Can be distinguished by its definite polar pa- pillae. Prescott (1962) mentioned that this alga is often collected in colonies of two to eight cells. Pediastrwn duplex Meyen (Fig. 8). Colony perforate with lens-shaped spaces between cells; inner cells shaped like short, fat H's; peripheral cells with inner margins more or less straight, outer margins concave with blunt-tipped, tapering processes; cells about 8 jum in diameter; colony with about 100 cells, 63 jum across (PrescoU 1962:223). Abundant in early June but soon replaced by P. duplex var. gracilimum, which Prescott (1962) noted as a growth form of typical plant. Latter found throughout the summer. Pediastrum duplex var. gracilimum West & West (Fig. 9). Colony with large perforations; body of cells narrow, equal in width to pro- cesses of peripheral cells; processes not taper- ing, or only slightly tapering; cells larger than typical plant, up to 25 jum in diameter (Prescott, 1962, p. 224). Rare in June but be- came more common in July and August. Scenedesmus quadricauda var. longispina (Chod.) G. M. Smith (Fig. 10). Colony of 4-8 cells in one series; cells widely variable in size, 5-13 ]um in diameter, 15-27 jum long, oblong-cylindric with lateral walls in full contact with adjacent cells; outer cells with long, curved spine at each pole; inner cells without spines (Prescott 1962:280). Abundant in plankton samples in late July and early August. Resembles S. opoliensis but separated on basis of amount of lateral wall contact be- tween adjacent cells. Cells of S. quadracauda var. longispina in contact with adjacent cells along entire lateral walls. Order: Cladophorales Cladophora glomerata (Lemm.) Kuetzing (Fig. 11). Filaments successively and regu- larly branched, branches usually crowded in outer parts of plant; cells cylindrical; apical cells attenuate slightly to a bluntly rounded end; cells of main axis 75-100 jum in diame- ter, six to seven times diameter in length; cells in branches 35-50 jum in diameter, three to six times diameter in length (Prescott, 1962:138). Found free-floating after becom- ing detached from rocks in splash zone along lake shore. This taxon was most important lit- toral alga in lake. Division: Chrysophyta Order: Ochromonadales Dinobryon divergens Imhof (Fig. 52). Colo- nies much branched and widely diverging; lo- ricas conical, posterior portion usually bent at an angle; lateral margins diverge then change direction, suddenly becoming con- vergent, then flare out again at mouth; lo- ricas 7-8 ]U,m in diameter, 32-40 /xm long 92 Great Basin Naturalist Memoirs No. 5 (Prescott 1962:378). Most common Dino- hnjon species in our study. Most abundant at movith of Provo River but common in some lake plankton samples. Division: Bacillariophyta Order: Rhizosoleniales Cyclotella kutzingiana Thwaites (Fig. 12). Cell diameter 8-13 jum; striae 16-20 in 10 \xm (Hustedt 1930:98). Common throughout lake. Cyclotella meneghiniana Kuetzing (Fig. 13). Cell diameter 10-13 jum; striae 6-9 in 10 [xm (Hustedt 1930:100). One of most common species throughout lake. Melosira granidata (Ehr.) Ralfs (Fig. 14). Cells 12-21 jLim long by 7-18 jum wide; striae 6-12 in 10 |Lim (Hustedt 1930:87). Common throughout lake. Melosira granulata var. angustissima Muel- ler (Fig. 15). Cells 12-17 jUm long by 47 jum wide; striae 6-12 in 10 jum (Hustedt 1930:88). Can be collected in large numbers through- out lake. Together with nominate, probably most frequent and abundant of diatom spe- cies. Melosira italica (Ehr.) Kuetzing (Fig. 16). Cells 12-13 jLtm long by 14-15 jum width; striae 17-18 in 10 jum (Hustedt 1930:91). Common in some years in the lake. Melosira varians C. A. Agardh (Fig. 17). Cells 11-20 jLim long by 11-14 jum wide (Hus- tedt 1930:85). Taken in low numbers from sites throughout lake. Order: Fragilariales Diatoma vulgare Bory (Fig. 23). Cells 34-52 JLtm long by 11-12 jum wide; costae 5-8 in 10 jum; striae indistinct (Patrick and Rei- mer 1966:109). Throughout lake in low num- bers. Fragilaria brevistriata var. inflata (Pant.) Hustedt (Fig. 18). Cells 12 jum long by 4-5 /xm wide; striae 14-17 in 10 jum (Patrick and Reimer 1966:129). Frequent throughout lake. Fragilaria constrtiens (Ehr.) Grunow (Figs. 19, 21, 22). Cells 9-18 jum long by 5-12 jum wide; striae 11-16 in 10 jum (Patrick and Rei- mer 1966:125). Quite common in Goshen Bay and midlake areas. Fragilaria constrtiens var. venter (Ehr.) Gnmow (Fig. 20). Cells 6-7 jum long by 4-5 [xm wide; striae 12 in 10 jum (Patrick and Rei- mer 1966:126). Common throughout lake. Fragilaria crotonensis Kitton (Fig. 24). Cells 78-83 jum long by 3-4 jum wide; striae 13-15 in 10 jum (Patrick and Reimer 1966:121). Common at both Goshen and boat harbor areas and at scattered sites throughout south and midlake regions. Fragilaria vaucheriae (Kuetz.) Petersen (Fig. 26). Cells 6-43 jum long by 4-6 jum wide; striae 11-16 in 10 jum (Patrick and Rei- mer 1966:120). Often collected abundantly throughout lake. Frustule shape is highly var- iable. Asteriojiella formosa Hassall (Fig. 25). Cells 50-77 jum long by 2-3 jum wide; striae 30 in 10 jum (Patrick and Reimer 1966:159). In moderate numbers throughout entire lake early in spring and summer. Order: Achnanthales Cocconeis placentiila var. lineata (Ehr.) Van Heurck (Fig. 28). Cells 15-47 [xm long by 10-30 jum wide; pseudoraphe valve striae 18-20 in 10 jum; raphe valve striae 19 in 10 jum (Patrick and Reimer 1966:242). Common in samples throughout lake. Achnanthes minutissima Kuetzing (Fig. 29, 30). Cells 5-29 jum long by 3-5 jum wide; pseudoraphe and raphe valve striae 22-32 in 10 jum (Patrick and Reimer 1966:253). Com- mon in many samples. Order: Naviculales Gyrosigma acuminatum (Kuetz.) Ra- benhorst (Fig. 34). Cells 79-119 jum long by 12-19 jum wide; longitudinal striae 18 in 10 jum; transverse striae 17-18 in 10 jum (Patrick and Reimer 1966:314). Frequent in all parts of lake. Fleurosigma delicatulum W. Smith. Cells 140-200 jum long by 16-22 jum wide; longitu- dinal and diagonal striae 19-22 in 10 jum (Pa- trick and Reimer 1966:336). Taxon character- ized by its narrow, sigmoid shape and its angled striae. Rather common in Geneva and Goshen areas of lake, often as an epiphyte. Diploneis S7nithii var. dilatata (M. Perag.) Boyer (Fig. 27). Cells 25-50 jum long by 16-25 jum wide; costae 8-10 in 10 jum (Pa- trick and Reimer 1966:411). Common throughout lake. Navicula capitata var. hungarica (Grun.) 1981 Utah Lake Monograph 93 ^ \ n 15 lOiim Figs. 12-23: 12, Cyclotella kutzingiana; 13, Cychtella meneghiniana; 14, Melosira granuhta; 15, Melosira granulata var. angustissima; 16, Melosira italica; 17, Melosira varians; 18, Fragilaria brevistriata var. inflata; 19, Fragilaria con- struens; 20, Fragilaria construens var. center; 21-22, Fragilaria construens; 23, Diatoma vulgare. All figures are print- ed to the same scale. 94 Great Basin Naturalist Memoirs No. 5 it 24 Figs. 24-34: 24, Asterionella forinosa; 25, Fragilaria crotonensis; 26, Frugilaria vaticheria; 27, Diploneis smithii var. dilatata; 28, Cocfonm placentula var. /ine«/!,v; 29-30, Ac/ui«ri^/u'.s »iinr/fi.s.v!»ifl; 31, Navicida capitata var. hungarica; 32-33, Navicula cryptocephala var. veneta; 34, Gijrosigmii (uiiminatum. All figures are printed to the same scale. 1981 Utah Lake Monograph 95 Ross (Fig. 31). Cells 16-22 {xm long by 5-6 jLim wide; striae 7-10 in 10 /xm (Patrick and Reimer 1966:537). In moderate numbers from all areas of lake. Naviciila cryptocephala var. veneta (Kuetz). Rabenhorst (Fig. 32, 33). Cells 10-21 jum long by 4-6 [xm wide; striae 13-16 in 10 jum (Patrick and Reimer 1966:504). Frequent at all collecting stations. Navicuki graciloides A. Mayer (Fig. 36). Cells 27-34 jitm long by 7-8 jum wide; striae 10-14 in 10 jum (Patrick and Reimer 1966:516). Frequent at all transects through- out collecting seasons. One of most common species in our studies. Navicitla salinarum var. intermedia (Grun.) Cleve (Fig. 37). Cells 34-37 jum long by 7-8 jLim wide; striae 14-16 in 10 ju,m (Patrick and Reimer 1966:503). Frequently at many col- lecting localities. Navicula tripunctata (Muell.) Bory (Fig. 35). Cells 35-55 jum long by 8-10 jiun wide; striae 10-12 in 10 jum (Patrick and Reimer 1966:513). In moderate numbers from many collecting localities. Caloneis ainphisbaena (Bory) Cleve. Cells 68-79 jum long by 22-26 /xm wide; striae 13-20 in 10 /xm (Patrick and Reimer 1966:579). Frequently throughout lake. Caloneis fenzlioides Cleve-Euhler (Fig. 38). Cells 86-96 /xm long by 25-30 /xm wide; striae 11-15 in 10 /xm (Cleve-Euler 1955:88). Rather common at many collecting localities. Amphora ovalis (Kuetz.) Kuetzing (Fig. 43). Cells 30-73 /im long by 6-15 /im wide; ventral striae 10-13 in 10 /un; dorsal striae 9-12 in 10 pun (Patrick and Reimer 1975:68). Abimdant at most collecting sites throughout our studies. Amphora ovalis var. affinis (Kuetz.) Van Heurck ex De Toni (Fig. 49). Cells 11-35 /xm long by 7-10 /im wide; ventral striae 12-16 in 10 /xm; dorsal striae 13-16 in 10 /un (Pa- trick and Reimer 1975:69). Taxon distin- guished from nominate variety by its smaller size and rectangular central area. Common throughout lake. Cymbella affinis Kuetzing (Fig. 44). Cells 27-47 /im long by 9-15 /xm wide; ventral striae 9-11 in 10 /xm; dorsal striae 10-12 in 10 /xm (Patrick and Reimer 1975:57). Com- mon throughout lake. Cymbella prostrata (Berk.) Cleve (Fig. 46). Cells 28-55 /xm long by 10-24 /xm wide; ven- tral striae 7-9 in 10 /xm; dorsal striae 8-11 in 10 /im (Patrick and Reimer 1975:40). Com- mon only in northern part of lake. Cymbella minuta var. silesiaca (Bleisch ex Rabh.) Reimer (Fig. 51). Cells 25-34 /xm long by 10-12 /xm wide; ventral striae 9 in 10 /xm; dorsal striae 9-14 in 10 /xm (Patrick and Rei- mer 1975:49). Very widespread and often common throughout lake. Gomphonema angustatum (Kuetz.) Ra- benhorst (Fig. 42). Cells 14-38 /xm long by 6-7 /xm wide; striae 11-16 in 10 /xm (Patrick and Reimer 1975:125). Common throughout lake. Gotnphonema intricatum Kuetzing (Fig. 40). Cells 31-70 /xm long by 7-12 /xm wide; striae 10-13 in 10 /xin (Patrick and Reimer 1975:134). Frequent at most collecting local- ities. Gomphonema olivaceum (Lyngb.) Kuetz- ing (Fig. 41). Cells 12-36 /xm long by 6-8 /xm wide; striae 10-13 in 10 /xm (Patrick and Rei- mer 1975:139). Common in all parts of lake. Gomphonema ventricosum Gregory (Fig. 39). Cells 33-50 /xm long by 9-11 /xm wide; striae 12-13 in 10 /xm (Patrick and Reimer 1975:137). Occasionally common in some samples. Order: Nitzschiales Nitzschia dissipata (Kuetz.) Grunow (Fig. 45). Cells 19-36 /xm long by 4-5 /xm wide; striae not resolvable; keel punctae 7-9 in 10 /xm (Hustedt 1930:412). Collected frequently from all transects. Nitzschia filiformis (W. Smith) Hustedt (Fig. 48). Cells 27-78 /xm long by 5 /xm wide; striae 32-34 in 10 /xm; keel punctae 7-10 in 10 /mi (Hustedt 1930:422). Frequent from most collecting localities. Nitzschia inconspicua Grunow (Fig. 47). Cells 6-15 /xin long by 3-4 /xm wide; striae 26-28 in 10 /xm (Lange-Bertalot 1976: 265-266). Nitzschia perminuta Grunow (Fig. 50). Cells 10-12 /xm long by 3 /xm wide; striae 24-35 in 10 /xm; keel punctae 11-13 in 10 /xin (Lange-Bertalot 1976:263). Collected fre- quently from all transects. Nitzschia hantzschiana Rabenhorst. Cells 12-19 /xm long by 2-3 /xm wide; striae 20-24 96 Great Basin Naturalist Memoirs No. 5 Figs. 35-42: 35, Navicula tripunctata; 36, Navicula graciloides; 37, Navicula salinarwn var. intermedia; 38, Ca- loneis fenzlioides; 39, Gomphonema ventricosiim; 40, Gomphonema intricatum; 41, Gomphonema olivaceum; 42, Gomphonema tingustatuni. All figures are printed to the same seale. 1981 Utah Lake Monograph 97 Figs 43-51- 43 Amphora ovalis; 44, Cymbella affinis; 45, Nitzschia dissipata; 46, Cymbella prostrata; 47, Nitzschia incon.^icua; 48, Nitzschia filiformis; 49, Amphora ovalis var. affinis; 50, Nitzschia perminuta; 51, Cymbella minuta var. silesiaca. All figures are printed to the same scale. 98 Great Basin Naturalist Memoirs No. 5 Table 2. Algae standing crop in Utah Lake at selected sites along three permanent transects during the summer of 1974. The numbers represent total algal cells, colonies, and filaments per liter. Transect Goshen Bay Date A B c D A B 13 June 1974 1,007 1,702 2,417 1,778 10,528 619 20 June 1974 26,875 250 2,344 1.3,111 14,800 13,444 3 July 1974 24,917 48,500 39,250 78,667 17,506 30,042 8 July 1974 479,444 146,500 99,000 — 180,167 278,833 18 July 1974 629,167 216,250 260,500 203,3.33 922,222 710,416 27 July 1974 449,167 412,500 179,722 355,000 513,194 .353,472 7 August 1974 59,815 30,000 20,375 122,917 1,111,667 280,000 15 August 1974 - - 226,562 2,943,750 193,056 173,177 in 10 jum; keel punctae 9-11 in 10 jam (Hustedt 1930:415). Frequent from all collecting sites. Division: Euglenophyta Order: Euglenales Euglena gracilis Klebs (Fig. 53). Plant uni- cellular and free swimming; cells metabolic, short fusiform to ovoid; chloroplasts many, discoid, distributed through cell; cells 20-22.5 jum in diameter, 37.5-50 jum long, may stretch to 75 jum long (Prescott 1962:393). Our most common Euglena. Abundant at mouth of Provo River, usually found with E. ehrenbergii and E. oxyuris. Division: Pyrrophyta Order: Peridiniales Ceratiiim hirundinella (Muell.) Dujardin (Fig. 54). Plant unicellular and solitary; cells narrowly fusiform with one apical horn and 2-3 stouter and shorter basal horns; apical horn straight, tnmcately flattened at apex; cells 30-72 jum wide, 100-400 jum long (Pre- scott 1962:437). Although rare in early June, one of dominant plankters throughout re- mainder of summer. Often abundant enough to color water muddy-brown and to plug plankton nets. Division: Cyanophyta Order: Chroococcales Microystis aeruginosa Kuetz. em. Elenkin (Fig. 55, 56). Colony spherical when young, becoming irregularly lobed and clathrate when mature; cells spherical and crowded within hyaline gelatinous matrix; cell con- tents blue green, highly granular, with con- spicuous pseudovacuoles; cells 3-4 jum in di- ameter (Prescott 1962:456). Common to abundant in most plankton samples. Order: Nostocales Anabaena spiroides var. crassa Lemmer- mann (Fig. 57). Trichomes spiral, solitary or entangled; cells spherical, pale blue green in color; cells 10-12 jum in diameter; hetero- cysts subspherical, 10 juin in diameter, 12 jum long; akinetes oblong, 20 jum in diameter, 25-30 jLim long (Prescott 1962:518). Can be confused with A. flos-aquae but is less blue, less granular, more regularly coiled, and with larger cells. Abundant to common in most plankton samples. Occasionally forms fairly large blooms. Aphanizomenon flos-aquae (Lemm.) Ralfs (Fig. 58). Trichomes parallel, united in bun- dles or flakes to form macroscopic aggre- gates; apices broadly romided, not attenuate; cells 5-6 jLim in diameter, 6-8 jum long, with numerous conspicuous pseudovacuoles; het- erocysts oblong or cylindrical (Prescott 1962:528). Usually most abundant and con- spicuous summer plankter in Utah Lake. Quantitative Sampling We have also performed quantitative sam- pling of the algal standing crop of Utah Lake. Our most complete data were collected dur- ing the 1974 collecting period. These data show that the standing crop of the lake was low during the spring and early summer (Table 2). At that time commimity diversity was high and the standing crop was divided 1981 Utah Lake Monograph 99 Table 2 continued. and site Boat Harbor D E Geneva C A B C D E 1,424 1,448 625 647 719 1,971 743 5,590 — 2,055 2,311 5,750 17.500 5.939 144,667 — 35,625 27,778 51,250 293,499 19.850 41,917 16,958 5,944 263,8a3 174,333 104.667 857.016 954,384 199.653 120,500 75,3.33 917,361 811,111 402.083 _ 119,666 906,249 468,750 568,750 351,389 242,014 203,819 277,083 457,291 - _ — 114,583 280,417 74,167 605,556 701,042 300,694 6,333,333 102,292 284,722 591,667 450,000 15,8.33,332 6,944,444 22.750,000 77,816,656 2,1,33,333 between several taxa (Whiting et al. 1978). As the summer progressed community diver- sity decreased but standing crop increased. By late summer the standing crop was com- posed of essentially two species, Aphanizonie- non flos-aquae and Ceratium hinindinella. The high diversity as measured by the total number of species occurring in the lake coupled with the high late summer biomass leads us to conclude that Utah Lake repre- sents a somewhat imique ecosystem. It is sim- ilar to certain other saline eutrophic systems in North America and Australia. Further studies on the algae of this system are pres- ently vmderway. Literature Cited Bingham, C. C. 1974. Recent sedimentation trends in Utah Lake. Unpublished thesis. Department of Geology, Brigham Young Univ. Provo, Utah. BoLLAND, R. F. 1974. Paleoecological interpretation of the diatom succession in recent sediments of Utah Lake, Utah. Unpublished dissertation. De- partment of Biology, Univ. of Utah, Salt Lake City, Utah. Brown, R. B. 1968. A fall and winter population study of the macroinvertebrate fauna of Lincoln Beach, Utah Lake, with notes on invertebrates in fish stomachs. Unpublished thesis. Department of Zo- ology, Brigham Young Univ. Provo, Utah. Cleve-Euler, a. 1955. Die diatomeen von Schweden und Finnland. Kungl Sveska Veten. Hand. N.S. 5. 232 pp. Harding, W. J. 1970. A preliminary report on the algal species presently found in Utah Lake. Great Ba- sin Nat. 30:99-105. 1971. The algae of Utah Lake, Part II. Great Ba- sin Nat. 31:125-1.34. Hem, J. D. 1970. Study and interpretation of the chem- ical characteristics of natural water. 2d ed. Geo- logical survey water-supply paper 1473. U.S. Government Printing Office, Washington, D.C. Hunt, B. P. 1940. A study of the Crustacea of Utah. Un- published thesis. Department of Zoology, Brig- ham Young Univ., Provo, Utah. HusTEDT, F. 1930. Bacillariophyta (Diatomeae). In A. Pascher, Die Susswasser-Flora Mitteluropas. Heft 10. Gustav Fischer, Jena, Germany. 468 pp. Lange-Bertalot, H. 1976. Eine revision zur taxonomie der Nitzschiae Lanceolatae Grunow. Die "Klas- sischen" bis 1930 beschreibenen Susswasserarten Europas. Nova Hedwigia 28:253-307. Patrick, R., and C. W. Reimer. 1966. The diatoms of the United States, v. I. Acad. Nat. Sci. Phil., Monograph 13. 688 pp. 1975. The diatoms of the United States, v. II, part I. Acad. Nat. Sci. Phil., Monograph 13. 213 pp. Prescott, G. W. 1962. Algae of the western Great Lakes area. William C. Brown Company Pub- lishers. 977 pp. 1970. How to know the freshwater algae. Wil- liam C. Brown Company Publishers. 348 pp. Smith, G. M. 1926. The plankton algae of the Okoboji region. Trans. Amer. Microsc. Soc. 45:156-2.33. St. Clair, L. L., and S. R. Rushforth. 1976. The dia- toms of Timpanogos Cave National Monument, Utah. Amer. J. Bot. 63:49-59. Tanner, V. M. 1931. Fresh-water biological studies at Utah Lake. Proc. Utah Acad. Sci. 8:198-203. Thienemann, a. 1961. Die Binnengewasser, v. 16, part 5. 7/1 G. Huber-Pestalozzi, Das Phytoplankton des Susswassers. Zurich. 744 pp. West, W., and N. Garter. 1923. A monograph of the British Desmidaceae. Reprint, Johnson Reprint Corporation, 1971. Whiting, M. C, J. R. Brotherson, and S. R. Rushforth. 1978. Environmental interaction on summer algal communities in Utah Lake. Great Basin Nat. .38:31-41. 100 Great Basin Naturalist Memoirs No. 5 Figs. 52-58: 52, Dinohnjon dive I gens 53 I tigluw guidlts 11 ( (Kilnnn hnimdmdld 55-56, Microcystis acnifii- nosa; 57, Anabaena spiwides var. < lassa 58 \pli(inizomenon flos (Kjikk Ml limnes except 54 and 55 are drawn to the same scale. Scales provided repu s( nt 10 /uii. MACROINVERTEBRATE AND ZOOPLANKTON COMMUNITIES OF UTAH LAKE: A REVIEW OF THE LITERATURE James R. Barnes' and Thomas W. Toole''^ Abstract.— Early studies on the macroinvertebrates and zooplankton of Utah Lake were taxonomic in nature. Since the late 1960s, niacroinvertebrate studies have concentrated on the Go,shen Bay area of Utah Lake. The rocky shore niacroinvertebrate community along the eastern shore of Goshen Bay is the most diverse and productive in Utah Lake (Toole 1973). The dominant organisms are the amphipod Hijalella azteca and the chironomid Dicroten- dipes fumidus. Also present along the eastern shore is an extensive zone of the sponge Meyenia flttviatilis (Smith 1972). Two taxa, Chironomidae and Oligochaeta, dominate the silty-ooze community in the southern portion of Utah Lake (Barnes et al. 1974). The life histories and the microdistributional patter.is of the two dominant chironomids found in the silt-ooze area of Go.shen Bay, Tanypus steUatiis and Chironomiis jrommeh, have been extensively stud- ied by Shiozawa and Barnes 1975. The distribution and abundance of the zoopknkton in Utah Lake has been studied for one summer (Hanson et al. 1974). Little is known about the dynamics of the zooplankton community in Utah Lake. The first studies on the macroinvertebrate and zooplankton communities of LItah Lake were basically faunal lists of the protozoans, zooplankton, and Mollusca found in Utah Lake (Chamberlin and Jones 1929, Hunt 1940, Tanner 1930, 1931). The identifications of the species reported in the above papers have not been reexamined. Between 1940 and 1968 the macroinvertebrates received little, if any, attention. Brown (1968) con- ducted the first extensive study on the littoral macroinvertebrates of the Lincoln Beach area. Most studies since then have concen- trated on the Goshen Bay region. This area, consi.sting of approximately one-third of the lake's total surface area, will be removed from the lake proper if the propo.sed Goshen Bay Dike (part of the Bureau of Reclama- tion's Central Utah Project) is built. This paper reviews the Hterature of the macroinvertebrate and zooplankton commu- nities of Utah Lake. I. Littoral Zone For a general discussion of the biological, chemical, and physical characteristics of lake littoral zones, see Wetzel (1975). Littoral zone studies in Utah Lake have concentrated on the rocky area along the eastern shore of Goshen Bay. In Utah Lake this rocky zone is the most extensive littoral area and supports a productive and diverse macroinvertebrate commimity (Toole 1974). In this area there are two main substrate types: compacted cal- careous tufa (lacustrine) and rubble (Bissel 1942). Along the western shore of Goshen Bay, a similar rocky zone is found, although not as extensive. The eastern shoreline has numerous saline springs that are high in free carbon dioxide, bicarbonate alkalinity, and sulfate (Toole 1974). Brown (1968) studied the fall and winter macroinvertebrate populations of Lincoln Beach. Samples were taken with a circular sampler at six stations along a 300 m stretch of Ribble beach at a water depth of 0.5 m. The amphipod crustacean, Hyalella azteca, was the dominant macroinvertebrate in num- bers, with the highest standing crop in Sep- tember (mean number = l,208/m2). The next most dominant was the chironomid Tanytarsiis sp. The highest density of this midge was in November (mean number = 320/m2). Identification of this chironomid as Tanytarsus sp. is incorrect; it is probably Dicrotendipes fumidus (Toole 1974). The leech, HelobdeUa stagnalis, was next in abun- dance (150/m2). Other organisms collected were a snail, Physella utahensis; a trichopte- 'Department of Zoology, Brigham Young University. Provo. Utah 84602. 'Present address: Tennessee Valley Authority, Florence, Alabama, 35630. 101 102 Great Basin Naturalist Memoirs No. 5 ran, Polycentropus sp.; and a water mite, Le- bertia sp. Toole (1974), using concrete artificial sub- strate samplers, studied the standing crop (numbers and biomass) and the annual popu- lation trends of the dominant macroinverte- brates foimd in the nibble and lacustrine hab- itat along the eastern shore of Goshen Bay. The period of study was from March 1972 through May 1973. Throughout this study pe- riod the samplers were retrieved from an av- erage water depth of 0.8 m. In the rubble area the amphipod HijaUela azteca and the chironomid Dictrotendipes fumidus were the dominant organisms on the samplers. Other organisms collected were Polycentropus cine- reiis, a trichopteran; Helohdella stagnalis, Dina parva, and Erpohdella punctata, leeches; Amhrysus mormon, a naucorid he- mipteran; and the gastropod Phy sella uta- hensis. At the lacustrine sampling site the same species were collected, plus a planarian worm, Dugesia dorotocephala. Standing crop estimates were always higher from the rubble area than the lacustrine. In the rubble area the standing crop values depended on wheth- er or not a set of samplers was within the in- fluence of a saline spring. Those samplers within this influence always had a greater "algal mat" growing on them and the highest numbers of associated Hyalella azteca. The high concentration of free carbon dioxide and bicarbonate alkalinity in the spring water may be the reason for the higher algal stand- ing crop. It is known that H. azteca feed on filamentous green and blue green algae and have the ability to select sediments that con- tain viable microflora (Cooper 1965, Har- grave 1970). The number of Hyalella azteca reported by Toole from the rubble area is the highest found in the literature. The maximum esti- mate was 37,898/m2 for August 1972. The highest biomass value (wet weight) was 66.5 gms/m2 for April 1973. Assuming an 85 per- cent water content, the dry weight estimate would be 9.9 gms/m2. These high standing crop estimates of H. azteca can probably be attributed to three factors: (1) an excellent substrate for epibenthic algae provided by the rubble and pieces of lacustrine substrate, (2) the eutrophic condition of Utah Lake and additional nutrients provided by saline springs, and (3) the combined effect of a shal- low water depth over most of the littoral area and high water temperatures. In March, April, and May, 1972, the H. az- teca population consisted entirely of first- and second-year adults— the first-year adults making up 75 percent of the population. Im- matures appeared in the population in June and dominated, in numbers, through October, thus making up 50-60 percent of the popu- lation. During this same time period, the numbers of second-year adults oscillated be- tween 10-15 percent of the total population. In November, when the first year adults be- came dominant, there was a dramatic de- crease in the percentage of immatures. The population overwintered as immatures and first- and second-year adults. In April 1973 (the first sample taken after the ice came off the lake) the population showed the same composition as found in November 1972. In May 1973 only first- and second-year adults were present in the population. The chironomid Dicrotendipes fumidus overwinters as second, third, and fourth in- star larvae, with the fourth being the most abundant. A major emergence occurred in March 1972 about three weeks after the ice broke up. Adults were found in the sampling area throughout the summer, which indicates a long emergence period. However, the emergences that took place throughout the summer were much smaller than the initial emergence. The highest larval density esti- mate was 21,421/m2 in July 1972. At this time, the population consisted of second, third, and fourth instar larvae, with the third being dominant. The sieve used in this study restrained only the second, third, and fourth instar larvae. The high wet weight biomass estimate was 9.5 gms/m^ or 1.4 gms/m^ dry weight in September 1972. In that month third and fourth instar larvae dominated the population. These high estimates are from artificial substrate samplers that had been located within the influence of spring water. The numbers of Hyalella azteca found on sam- plers located outside the influence of spring water exceeds other estimates foimd in the literature (Cooper 1965, Anderson and Hoo- per 1956, Buscemi 1961, Gerking 1962). 1981 Utah Lake Monograph 103 The littoral zone along the eastern shore of Goshen Bav supports the most productive and diverse niacroinvertebrate community in Utah Lake (Toole 1974). When converted to dry weights (assuming a water content of 85 percent) and on the basis of only two species {HyaleUa azteca and Dicrotendipes furnidus), the standing crop biomass values for this area ranks Utah Lake as one of the top 10 lakes found in the United States in terms of benthic standing crop (Cole and Underbill 1965). This comparison does not take into account the other species present in this area or the ex- tensive zone of the sponge Meyenia fliivia- tUis (Smith 1972). The trichopteran Polycentropus cinereiis is rare in comparison to HyaleUa azteca and Dicrotendipes fumidus. Emergence takes place in April along the Goshen Bay littoral area. The highest densities were l,937/m2, November 1972 (Toole 1974). General population trends and emergence patterns of the dominant macroinverteb rates in the lacustrine area follow those found in the rubble area. The standing crop of the la- custrine area was smaller than reported for the nibble area. Brown's (1968) standing crop estimates of HyaleUa azteca from the lacus- trine area are difficult to compare with those obtained by Toole (1974) because Brown's sampling was limited to a water depth of 0.5 m or less. Toole's maximum estimate from the lacustrine area was 15,121/m2, August 1972, which is 10 times greater than Brown's maximimi estimate. Artificial substrate sam- plers retrieved from the lacustrine area al- ways had less algae and more silt than sam- plers from the rubble area. Tillman and Barnes (1973) studied the re- productive biology of the leech Helobdella stagnalis in the same rubble area studied by Toole (1974). The annual reproductive cycle of Helobdella stagnalis in Utah Lake is con- siderably different from the cycle fovind in Whiteknights Lake, Reading, Berkshire, Eng- land (Mann 1957). Mann reported that over- wintering adult leeches produced a brood of young in May and then died in June. Over 50 percent of the new brood matured and repro- duced in July and August and died after re- production. The next year's overwintering leeches were composed of June leeches that did not mature and July-to-August leeches produced by the mature June brood leeches. Tillman and Barnes found in Utah Lake that overwintering adult leeches have a first brood of young in May that release from the adults in mid-June. Then the same adults bear a second brood of young in late June and early July. The adults disappear from the population after the second brood of young. Very few first and second brood leeches ma- ture and reproduce that same summer. The leeches from the first and second brood then become the next overwintering population. n. Clay-Silt Area For a description of the substratum com- position, see Bingham (1974). Barnes et al. (1974) sampled the clay-silt area of the south- ern part of Utah Lake monthly from Septem- ber 1971 to September 1972, except when the lake was iced over. Two transects (1 and 2) were located in the area of Goshen Bay to be diked off and the other two (3 and 4) were located in front of the proposed dike (the area to be retained as part of the lake). Only two dominant taxa were found: Chirono- midae and Oligochaeta. Oligochaetes collected in this study were not classified. Preliminary examinations in- dicate that there are three dominant oligo- chaete species. During the period of study, the mean number of oligochaetes collected ranged from 8643/m2 to 26,192/m2. In gen- eral the oligochaetes showed a decrease in numbers during the spring and then an in- crease during late summer and early fall. There are at least three species of chirono- mids present in the silty clay area: Chiro- nomus frommeri, Tanypus stellatus, and Pro- cladius freemani. They were not separated to species when sorted to taxa and only total numbers were reported. The mean number of chironomids ranged from 237/m2 to 7167/m2. Like the oligochaetes, the chirono- mids showed a decrease in numbers during spring and then an increase during late sum- mer and fall. Because of the screen size used in sieving, the numbers of chironomids are represented by only second, third, and fourth instars of the larger species and third and fourth instars of the smaller species. Analysis of variance (ANOVAR) was used to compare the mean number of chironomids and oligochaetes in the following contrasts: 104 Great Basin Naturalist Memoirs No. 5 Transects 1 and 2 versus 3 and 4, transect 1 versus 2, and transect 3 versus 4. At the 0.05 level there was a significant difference be- tween the oligochaete means of transects 1,2 (area to remain in the lake) and transects 3,4 (area to be diked off). There were no signifi- cant differences between the oligochaete means in 1 versus 2 and 3 versus 4. The chi- ronomid means showed no significant differ- ences in any contrasts at the 0.05 level. The numbers of oligochaetes per square meter in Utah Lake are consistent with num- bers reported from other eutrophic waters. In Toronto Harbor, Lake Ontario, which i-s' grossly polluted, the oligochaete population averaged 96,000 /m2 (Brinkhurst 1972) with one worker reporting densities of well over a million/m2 (Aston 1973). The low number of oligochaete species present in the clay-silt of Utah Lake is consistent with other shallow lakes that also show little diversity in benthic habitat. Heuschele (1969) studied the benthic commimity of a shallow floodplain lake and found only three species of oligochaetes pres- ent. Utah Lake, like the flood plain lake, has little to no rooted aquatic vegetation present and a majority of the lake substratum is quite uniform with respect to chemical factors, temperature, depth, and light. Greater num- bers of oligochaete species are found in deep- er lakes with more diverse habitats. Thirty- three species have been reported from Lake Maggiore (Brinkhurst 1963) and 22 from Es- rom Lake (Berg 1938). In comparison with deeper, oligotrophic lakes (Thut 1969), Utah Lake has a low number of chironomid spe- cies. The density of chironomids found in the Goshen Bay area is consistent with that found in shallow lakes (Heuschele 1969). Shiozawa and Barnes (1977) studied the microdistributional patterns and life histories of larval Tanypus stellatus and Chironomus frommeri in Goshen Bay from July 1973 to August 1974. Vertical distribution data showed that over 90 percent of the larvae were located in the top 7.5 cm of the sub- stratum. Depth of penetration into the sub- stratum increased with the later instars. The C. frommeri larvae penetratd deeper than those of T. stellatus. Biomass was distributed bimodally. The mode at the 0-2.5 cm depth was due to high numbers of early instar lar- vae. The second mode, at the 17.5-20.0 cm depth, was due to the presence of fourth in- star C. frommeri larvae. The T. stellatus showed a contagious distribution in the early instars with a trend toward randomization within the later instar stages. The C. from- meri larvae rarely showed contagious distri- butions. This was likely related to their low abundance in the samples, making detection of a contagious distribution difficult. Larvae of T. stellatus overwintered in the first and second instar. This overwintering generation emerged in early July and gave rise to a second summer generation emerging ii^ August. Chironomus frommeri overwinter mainly as third and fourth instar larvae. Emergence occurred throughout the summer, although two strong emergence pulses were seen; one occurred in May and the second in July-August. III. ZOOPLANKTON Hanson et al. (1974) sampled the zooplank- ton in Utah Lake during a three-month peri- od from June to August 1974. Transects were chosen to represent three subenvironments within the lake. The northern or Geneva transect ran west from the settling pond spillway of United States Steel's Geneva Works. Five sites were sampled. The middle or Boat Harbor transect also had five stations Rmning west from a point just south of the mouth of the Provo River and north of Provo Bay. The southern or Goshen Bay transect, being shortest with only four sampling sites, ran west from Ludlow's sheep bams near Lincoln Beach. Samples were collected every nine days between 4 June and 15 August 1974. A complete list of the zooplankton identi- fied in this study is given below (those marked by an asterisk have not previously been reported): Copepoda Diaptomus spp. (two species) Cyclops spp. (two species) Cladocera Daphnia retrocurva Pseudosida bidentata Leptodora kindtii "Bosmina longirostris Chydorus spliaericus Ceriodaphnia sp. 1981 Utah Lake Monograph 105 Rot if era Keratella cochlearis Keratella quadrata f valga Keratella quadrata ffrenzeli "Brachiomis caudatus Brachionus calcyflorus Brachionus hudapestensis Filinia terrninalis " Pohjarthra sp. {minor or remata) "Syncluieta sp. "Notoynmata sp. "Asplanchna sp. "Colurella sp. "CephalodeUa sp. through the summer in numbers of predatory cyclopoid copepods and Leptodora kindtii. No correlations between phytoplankton and zooplankton populations were made. Acknowledgments The authors would like to acknowledge Richard A. Heckmann and Elna B. Barnes for their help in the preparation of this manu- script. Literature Citep Most zooplankton species were present at all stations, though their frequencies varied rather widely. Areas influenced by the inflow from tlie Provo River showed more diversity, less dominance by few species, and larger standing crops. Using the variance to mean ratio (Elliott 1971), zooplankton distribution in total numbers was determined to be aggre- gated. Populations in large clumps make it very difficult to determine accurate standing crop estimates. For instance, two samples taken on the Boat Harbor transect at Station A on two consecutive days, 21 June, and 22 June, illustrate this. The 21 June sample con- tained 398,000 zooplankton/m3; the sample collected tlie following day contained only 50,000 zooplankton /m3. Relative densities of individual species in the two samples were also very different. Some zooplankton population trends were observed. In the northern two transects, the total zooplankton numbers peaked in late June and early July, then dropped off in Au- gust. No pattern was as obvious in Goshen Bay, although highest numbers were ob- served in early August. Trends in some popu- lations are reported. In early samples the ca- lanoid copepods dominated, with their dominance decreasing steadily throughout the summer; by August Daphnia retrocurva and Pseiidosido bidentata were found in slightly higher numbers than the calanoids. Pseudosida populations were stable, although Daphnia populations seemed to show a slight inverse proportionality to calanoid popu- lations. This tendency was more evident in Goshen Bay than in the other parts of the lake. A more obviovis trend was the increase Anderson, R. O., and F. F. Hooper. 1956. Seasonal abundance and production of littoral bottom fauna in a southern Michigan Lake. Trans. Anier. Micros. Soc. 75:259-270. Aston, R. J. 1973. Tubificids and water quality: a re- view. Environ. 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Office of Re- search and Monitoring, U.S. Environmental Pro- tection Agency, Washington, D.C. 68 pp. Brown, R. B. 1968. A fall and winter population study of the macroinvertebrate fauna of Lincoln Beach, Utah Lake, with notes on invertebrates in fish stomachs. Unpublished thesis, Brigham Young Univ. BuscEMi, P. A. 1961. Ecology of the bottom fauna of Parvin Lake, Colorado. Trans. Amer. Micros. Soc. 80:266-307. Chamberlin, R. v., and D. T. Jones. 1929. A descrip- tive catalog of the Mollusca of Utah. Bull. Univ. Utah, Biol. Ser. l(l):l-203. Cooper, W. E. 1965. Dynamics and productivity of a natural population of a freshwater amphipod Htjalella azteca. Ecol. Monogr. .35:377-394. Elliott, J. M. 1971. Some methods for the statistical analysis of samples of benthic invertebrates. 106 Great Basin Naturalist Memoirs No. 5 Freshwater Biol. Assoc. Sci. Publ. 25 (England). 143 pp. Gerking, S. D. 1962. Production and food utilization in a population of bluegill sunfish. Ecol. Monogr. 32:31-78. Hanson, B. J., T. A. Leslie, M. Murray, K. A. Roberts, L. L. St. Clair, T. W. Toole, and M. C. Whiting. 1974. Utah Lake plankton standing crop estimation incorporating. ERTS-1 Imagery. Final Technical Kept. National Science Founda- tion. Student Originated Studies— Project GY- 11530. 101 pp. Hargrave, B. T. 1970. Distribution, growth and seasonal abundance of Hijalella azteca (Amphipod) in rela- tion to sediment microflora. J. Fish. Res. Bd. Canada 27:685-699. Heuschele, a. a. 1969. Invertebrate life cycle patterns in the benthos of a floodplain lake in Minnesota. Ecology 50:998-1011. Hunt, B. P. 1940. A study of the Cnistacea of Utah. Un- published thesis, Brigham Young Univ. Mann, K. H. 1957. The breeding, growth and age struc- ture of a population of the leech Helobdella stag- nalis L. J. Anim. Ecol. 26:171-177. Shiozawa, D. K., and J. R. Barnes. 1977. The micro- distribution and population trends of larval Tan- yptts stellatiis Coquillett and Chironomtis from- meri Atchley and Martin (Diptera; Chirono- midae) in Utah Lake, Utah. Ecology 58: 610-618. Smith, C. E. 1972. The distribution of Meyenia fliwia- tilis at the Lincoln Beach area of Utah Lake with notes on the seasonal occurrence of gemmules. Unpublished thesis, Brigham Young Univ. Tanner, V. M. 19.30. Freshwater biological studies at Utah Lake, Utah. Free. Utah Acad. Sci., Arts, Lett. 7:60-61. 1931. Freshwater biological studies at Utah Lake, No. 2. Proc. Utah Acad. Sci., Arts, Lett. 8:199-203. Thut, R. N. 1969. A studv of the profundal bottom fauna of Lake Washington. Ecol. Monogr. 39:79-100. Tillman, D. L., and J. R. Barnes. 1973. The reproduc- tive biology of the leech Helobdella stagnalis L. in Utah Lake, Utah. Freshwat. Biol. 3:137-145. Toole, T. W. 1974. The benthic communities of the eastern rocky shore areas of Goshen Bay, Utah Lake. Unpublished thesis, Brigham Young L'niv. Wetzel, R. 1975. Limnology. Saunders, Philadelphia. 743 pp. FISHES OF UTAH LAKE Richard A. Heckmann,' Charles W. Thompson,- and David A. White^ Abstract.— There has been a drastic change in fish populations inhabiting Utah Lake during the last KX) years. When the pioneers first entered Utah Valley they found a well-established cutthroat trout population in Utah Lake and in the tributaries flowing into the lake. After intensive agricultural and industrial development this salmonid disappeared, and carp, white bass, and black bullhead are the common species today. The known history of the Utah Lake fisheries is summarized. Through proper management it is possible to establish a sport fishery of the common fish species currently in the Lake, including walleye, channel catfish, and largemouth bass. The ichthyofauna of Utah Lake may be an underrated natural resource. Today, no native sport fishery exists in Utah Lake, although sportsmen are harvesting introduced species. Utah Lake has a dynamic fishery that must be continually monitored and man- aged if it is remain productive. The ichthyofauna of Utah Lake has expe- rienced drastic changes since the white man entered Utah Valley to colonize the agricul- tural lands. This lake, which once had a wealth of trout, suckers, and minnows, now contains carp, white bass, and black bull- heads. Proper management of the sport fish and commercially important fish is of pri- mary concern to district fishery biologists. Utah Lake is a warm, shallow, eutrophic body of water in Utah County, Utah, which may be the most underrated natural resource for fishes in the state. The fishes currently in Utah Lake could be an important source of needed protein for human consumption in the near future. The native fishes once associated with the lake are the cutthroat trout, moimtain white- fish, Utah chub, leatherside chub, least chub, longnose dace, Utah sucker, webug sucker, June sucker, mountain sucker, mottled scul- Table L Utah Lake fish species in order of decreas- ing abundance as shown by gill net catches in 1958 and 1970. Order 1958 1970 Carp Utah chub Channel catfish Perch Utah sucker Black bullhead Walleye White bass White bass Black bullhead Carp Walleye Channel catfish Utah sucker pin (Bonneville), and Utah Lake sculpin (Ta- bles 1,3). Included are 4 families, 9 genera, 12 species, and 2 subspecies. There has been a drastic change in the ichthyofauna since man settled Utah valley. Accounts of the early history of Utah in- dicate that Utah Lake was a productive. Table 2. Pesticides and mercury in fish taken from Utah Lake in ppm (wet muscle tissue measure) (Smith 1973). Mean Range Mercury Carp and bullhead White bass' Dieldrin Carp Bullhead White bass' p,p-DDT Carp Bullhead White bass' p,p'DDE Carp Bullhead White bass' PCB's Carp Bullhead White bass' 0.152 0.030-0.470 0.050 0.012 0.000-0.023 0.007 0.004-0.010 0.011 0.011 0.000-0.036 0.012 0.003-0.020 0.021 0.020 0.000-0.056 0.007 0.000-0.013 0.056 0.115 0.000-0.200 0.100 0.100-0.100 0.180 'Analysis by WARF Research Institute, Madison, Wisconsin in November 1970. 'Department of Zoology, Brigham Young University, Provo, Utah 84602. 'Utah Division of Wildlife Resources, Fisheries. Springville, Utah, 84604. 'Media Services, Brigham Young University, Provo, Utah 84602. 107 108 Great Basin Naturalist Memoirs No. 5 beautiful lake teeming with native cutthroat trout weighing 15 to 16 pounds. Since the Mormon settlers entered Utah Valley in the early 1850s there has been a steady decline in the quality of fisheries. The once abimdant native cutthroat trout is now extinct and the large number of suckers that once existed are on the decline. Introduced species are now the most common fish in the lake (Tables 1 and 4). The major causes of the decline of the fisheries in Utah Lake include extensive com- mercial fisheries, water manipulation, agri- cultural practices, and pollution. Diversion and blocking of the feeder streams to Utah Lake reduced access to spawning areas used by the cutthroat trout and the suckers. Fluc- tuations in the water level, and water quality, poor agricultural practices, and increased sewage effluent reduced the water quality for the feeder streams and in Utah Lake. The in- troduction of exotic fish species caused exten- sive competition with the native fish stock. Carp became one of the most abundant fish, and their activities contribute greatly to the high turbidity of the lake water. The carp are, however, utilized to some extent by a lo- Table 3. Current status of native fishes of Utah Lake. Fish Status 1977 Comments Sahnonidae Sahno clarki (Bonneville cutthroat trout) Prosopium wilUamsoni (Mountain whitefish) Lake form extinct, river form hybridized Rare in lower Provo River Common to west side Wasatch Mountains. Probably two races: a large lake dweller and a river dweller. Grew to 18 pounds in the lake. Probably entered river deltas in the lake. Was common in early commercial fishery; called moiuitain herring. Cyprinidae Gila atraria (Utah chub) Very rare Common in lake until early 1960s. Probably eliminated by introduced walleyes and white bass. lotichthijs phlegethontis (Least chub) Gila copei (Leatherside chub) Rhinichthyes cataractae (Longnose dace) Catostomidae Catostomus ardens (Utah sucker) Catostomus fecundus (Webug sucker) Chasmistes liortis (Jime sucker) Catostomus playtrhi/nchus (Mountain sucker) Extinct Extinct Rare Rare-common Rare Few, status unknown Few still found in Kamas Valley-Provo River and other areas in Utah. Habitat loss in lake. Some in Kamas Valley-Provo River and other areas in Utah. Few in Current Creek south tributary, Utah Lake. Common in other streams in Utah. Once very common in Utah Lake and inlet streams. Filled rivers with spawners in spring. Mav be hybrid between June and Utah sucker. Widely distributed in lake. Once verv abundant, now near extinction. Probable plankton feeder; terminal mouth. Inlet streams of Utah Lake, never ventured far into lake. Cottidae Cottus bairdi scmisraher (Bonneville mottled sculpin) Cottus echinatus (Utah Lake sculpin) Manv Rare, none collected since 193()s Frovo Hi ind other inlet streams. Small spring inlet streams originating in Utah Valley. Conunon in Bonneville .sediments where fish fossils found. 1981 Utah Lake Monograph Table 4. Fish introductions in Utah Lake and its tributaries, 1880-1974. 109 Family, accepted common name Date, number introduced location Fate Chipeidae American shad 1887 (2,(K)0,(XX) fry), 1888 (2,(KK),(XK) fry) Utah Lake Utah Lake 1889; 1% lb shad. For sale— soon died out. Sahnonidae Silver salmon Rainbow trout 1927 (.325,000 fry) 1894, 1900 Utah Lake Provo River Died out. Probably sustained in Provo River Brown trout Prior 1900, planted regularly by 1910. Provo River, most inlet streams Became self-sustaining in Provo River. Lake trout 1894 (100,000 fry), 1900 (250,000 fry) 1900 (50,000 fry) Unknown Spring Creek Provo River near Heber, Utah 1905 evaluation, no favorable results Brook trout 1894 (500 12" long) 1895 (1,000 adults) 190.3-to present- occasional stocking Most inlet streams Up high in inlet streams and lakes 1905, doing well in Provo River; subsequently died out. Mostly put and take; some reproductions. Lake whitefish 1895 (2,(X)0,000 fry) 1919 (2,000,000 fry) 1921 (100,000 fry) Utah Lake Utah Lake Utah Lake No populations establi.shed. Grayling (.30,000 fry) Inlet streams, Utah Lake No populations established. Anguilidae American eel 1872 1887 (80 up to 18") Pond on Jordan River Jordan River 1874, l'/2 lb take near mouth of Provo River. 1894, few taken up to 30" from Utah Lake; never became established. Cyprinidae Gold fish 1881 (130 adults) (47 adults), occasional small releases throuj 1974 Ponds near Jordan River Utah Lake Few taken by commercial fishermen each year. Carp 1882 (200 young) 1883 (?) 1886-1903 several thousand Ponds near Jordan River Jordan River Utah Lake Successful; population rapidly expanded until very abundant in Utah Lake and lower inlet streams. Golden shiner 1969 (100,000 to 200,000) Various locations around Utah Lake Mav have become established. Fathead minnow 1969 (100,000 to 200,000) Various locations around Utah Lake. Occasional in littoral zone. Bullhead minnow (?) Various locations Occasional in small inlet streams. no Table 4 continued. Great Basin Naturalist Memoirs No. 5 Family, accepted Date, number common name introduced location Fate Ictaluridae Channel catfish 1888 Utah Lake Has become common in 1911 Utah Lake Utah Lake. Reduced 1919 Utah Lake in recent years. 1920 Utah Lake Black bullhead 1871 Jordan River 1900, became common in Utah 1873 Jordan River Lake fishery. Very abundant, 1893 (100 6-15") 1974. Percidae Yellow perch 1890 Utah Lake 1894, present in commercial 1891 (636) Utah Lake catches 1923 Utah Lake 1931 Utah Lake 1932 Utah Lake 1934, drought killed many. Occasional catch, 1974. Walleye 1952 (600,000) Utah Lake 1954 (300,000) Utah Lake First spawning runs. Provo 1956 (900,000) Utah Lake River, 1955 or 1956 1968-1973 (19,907,594) Lower Provo River Benjamin slough Centarchidae Smallmouth bass 1912 (160) Spring Creek Not established. 1914 (600) Spring Lake Fishery for short time then died out. Largemouth bass 1890 (mixed sizes) Utah Lake 1893, bass season opened. 1891 (1,700 fry) Utah Lake 1895, 2000 spawners taken for 1894 (100 adults) Utah Lake planting elsewhere. 1902-1913 Powell slough used as 1902, population down. 1912 (5,000,000 fry natural hatchery 1901, commercial seining hatched in Powell outlawed; became common slough) along shore. Green sunfish 1890 (mixed) Established in stream 1930-1949 Various inlet streams inlets. and Jordan River Bluegill 1890 (mixed) Various inlet streams Occasional along shore. and Jordan River Black crappie 1890 1895 (85 adults) Utah Lake Unknown but rarely if at all taken. 1931, 1932, 1933- Mouth of Provo River 1934, drought killed most. several thousand young Serranidae White bass 1956 (209 mixed) Utah Lake Very abundant. cal commercial fisherman and could become a source of human food in the future. White bass, another introduced species, is also very abundant in the lake. Table 5 lists the current species in Utah Lake and their relative abun- dance. (The text contains a description of each of the common species currently in Utah Lake.) 1981 Utah Lake Monograph 111 Table 5. (Checklist ot tlie fish species currently found in and near Utah Lake, Utah County, Utah, with infor- mation concerning their relative abundance. Species Abundance in 1977 Brown trout {Salmo trutta) rare (inlet streams) Cutthroat trout {Salino clarki) rare (extinct in Utah Lake) Rainbow trout {Sahno gahdncri rare (inlet streams) Carp (Ctjprinins carpio) very common Utah chub {Gila atraria) very rare Fathead minnow (Pimephales promelas) rare Golden shiner {Notemigonus cnjspleucas) rare Redside shiner (Richardsonius halteatus) rare Utah sucker [Catostomus ardens) common-rare June sucker {Chasniistes Horns) rare-extinct Webug sucker {Catostomus feciindus) rare Mountain sucker {Catostomus platijrhnchus) very rare Channel catfish {Ictalunts punctatus) common Black bullhead {Ictalurus melas) very common Mosquitofish {Gambusia affinis) common White bass {Morone chrysops) very common Largemouth bass {Micropterus salmoides) common Green sunfish {Lepomis cijanellus) common BluegiU {Lepomis macrochirus) common Yellow perch {Perca flavescens) rare Walleye {Stizostedion vitreum) common Mottled sculpin {Cottus bairdi) rare To date 25 species of fish have been in- troduced into Utah Lake (Popov 1949). Thir- teen of these introductions were successful and 11 failed (Table 4). The carp, white bass, black bullhead, channel catfish, and walleye have been the most successful. The status of the golden shiner and the fathead minnow is unknown, but it is hoped that these two min- now species will provide a forage fish for the larger piscivorous fish such as the walleye and largemouth bass. Today, no native sport fi.shery exists in Utah Lake. The fish species utilized by the sportsmen are all introduced. The most wide- ly fished-for species are the channel catfish, black bullhead, walleye, and white bass. The walleye fishery appears to be stabi- lized with annual stockings of sac-fry to sup- plement the natural spawn. There is sub- stantial fishing pressure for this species, particularly in the early spring during their spawning period. The number of walleye col- lected in nets and caught by fishermen in- creased in 1970 over that in 1958, a fact that shows the beginning of an established wall- eye fishery in the lake. A brief annotated history of the fisheries of Uah Lake prior to 1849 on to 1974 is found in Table 7. Origin of Native Fish Species The native fishes of Utah Lake are most nearly related to those of the Columbia River Drainage. The Columbia River element probably reached Utah Lake by means of a river connection established during the late Pliocene-Pliestocene, when the continued up- lift of the Sierra Nevada, glaciation, and vul- canism interacted to change the direction of Great Basin river outflow from a Mississippi- Atlantic Ocean connection to a Columbia River-Pacific Ocean connection (Hubbs and Miller 1948). Demographic evidence of this relationship is found in the similar genera of the families in Pliocene-Pliestocene times and recently (see Table 6). The reasons why some families and genera that were in Lake Bonneville are not now represented in Utah Lake or even in Utah, are not known. However, if Lake Bonneville dried up between 8000 and 5000 BC, leaving only springs and streams (Bissell 1968), then the more lake-dependent species could have been eliminated. This idea is supported by the fact that all native species of Utah Lake fish (1880 AD) had both lake and river spawning forms and depended heavily upon river-produced young for recruitment. In addition, Prosopium spilo- notus, a lake species, was common in Lake Bonneville but is now restricted to Bear Lake (Stokes et al. 1964). 112 Great Basin Naturalist Memoirs No. 5 Table 6. Comparison of fish faunas (families, genera) of Lake Idaho, Lake Bonneville, and Utah Lake. Lake Idaho Lake Bonneville Utah Lake drainage (Late Pliocene) (Late Pliestocene) 1880 A.D.) Salmonidae Salmonidae Salmonidae Salmo Salmo Salmo Prosopium Prosopium (2 spp) Prosopium Cyprinidae Ptychocheiliis Arcocheilus Cyprinidae Gila Cyprinidae Gila (2 spp) lotichthys Diastichus (2 spp) Mylocyprintis Mylopharodon (2 spp) Sigmopharyngodon Rhinichthyes Catostomidae Catostomidae Catostomidae Catostomus (5 spp) Chasniistes Catostomus Catostomus (2 spp) Chasmistes Deltistes (2 spp) Ictaluridae Ictahms Centrarchidae Archoplites Cottidae Cottidae Cottidae Cottus Cottus (2 spp) Cottus (2 spp) Fisheries, American Indian Period Founding of the Commercial Fishery— 1880 Although written records are few, there is evidence that fish from Utah Lake and its tributaries were utilized by various American Indian cultures that inhabited Utah Valley and adjoining areas. In 1776, Fathers Domin- quez and Velez de Escalante described Utah Lake as teeming with several kinds of edible fish. That the natives dried the fish for later consumption is evidenced by the supply of dried fish the Spanish took with them when they left Utah Valley (Auerbach 1943). Early trappers and explorers found similar utilization of the fisheries (Bagley 1964, Fre- mont 1845, Stansbury 1852), and they caught many of their fish during the spawning sea- son in late spring and early summer by wad- ing into a riffle and manually throwing them on to the bank (Pratt 1849). Remains found in archeological "digs" around Utah Lake have found fish use from 800 to 1300 AD by the Sevier-Fremont culture (Green 1961, Whee- ler 1968). Early Mormon settlers were also exposed to the Utah Lake fishery by the na- tive Americans whom they replaced in Utah Valley. The first Mormon pioneers stopped at Fort Bridger, Wyoming, where William Clayton recorded a discussion between Jim Bridger and Brigham Young (Clayton 1921). Bridger felt that the region around Utah Lake was the best country in the vicinity of the great Salt Lake, because there were timber near the streams and an abundance of fish in the streams, south from Utah Lake. The summer arrival of the Mormons (24 July 1847) into the Salt Lake Valley, the im- pending winter, the need to build shelter and prepare ground for crops, and the knowledge of those waiting to come left little time to ex- plore. However, in December 1847, Parley P. Pratt and party traveled to Utah Lake with a boat and fish net. They sailed the western side of the lake and caught a few mountain trout and other fish (Pratt 1888). Carter (1969) felt that their lack of success was because the trout went to deeper waters in the winter. However, Pratt's party fished the west side of Utah Lake, which was never known for its trout populations. 1981 Utah Lake Monograph 113 Table 7. Brief annotated history of the fisheries of Utah Lake, 1849-1974. Date' Activity Possible causes Prior to 1849 American Indians caught and used fish from Utah Lake for at least 500 years (Auerbach 1943, Fremont 1845, Green 1961). 1849 Spawning fish (trout, suckers, and mullet) in lower Provo River, dried or salted in barrels. Beginning of commercial fishery in Provo River and Utah Lake (Green 1961, Huntington 1847). Provided sustenance to Provo settlers who had to clear ground. 1850-1852 Spawning fish in rivers and streams still caught. Nets and traps more common, advent of boats and lake year-round fishing. Fishermen from Provo and other settlements. Lower Provo River Fi.shery predominates (Huff 1847). Settlement of American Fork, Lehi, Pleasant Grove, Springville, Spanish Fork (Palmyra), Payson, and Alpine— all consumed fish (Gardner, 1913, Hons 1950, Johnson 1900, Carter 1969). 1850-1860° Rapid increase in commercial fishing with year- round harvest; long seines introduced. Selling of fish common in Utah Valley and Salt Lake Valley. Permanent fish traps allowed along millrace in lake fishing streams. Gradual decline in American Indian fishing. Higher prices obtained in winter than summer. State, county, and local governments begins some regulation of fishing. Provo City regulated the Provo River, while Utah County regulated the fisheries of Utah Lake and other streams (Spanish Fork, Jordan River, Payson Creek, and Provo Bay streams) (Bean 1852, Utah Legislative Assembly 1855, Carter 1969). Mormon population grew from 6,000 in 1849 to 40,000 in 1860 (Arrington 1966). Drought and grasshopper plague, 1855-56 (Jarvis 1962, Madsen 1910). Severe winter weather and Indian depredations reduced cattle. Coming of Johnston's Army, 1857-58, added burden on resources as Salt Lake Valley settlers fled south (Arrington 1966). 1856 Peter Madsen begins long-term fishery at the mouth of Provo River and south (Carter 1969) 1860-1870 Decline in number of commercial fishing groups; consolidation of fishing areas. Peter Madsen picks up other areas for expanded fishery (J. Procd. Provo City Council 1866, 1872). Some decline in fishery noted. Manufacture of fish oil for leather and machinery began (Burton 1860, Carter 1959). All inlet streams of Utah Lake appropriated for irrigation by 1874. Loss of recruitment as age 0 fish turned out on the land (Israelson 1938). 1860-1974° Spawning fish, their eggs, and young destroyed by fluctuating water levels of inflow streams into Utah Lake; reduced fish populations (Winger 1972). Regulation of inflow streams primarily for irrigation. 1862 Territorial legislature took over regulation of Jordan River Fishery and outlawed fish traps (Utah Legislative Assembly 1866). Overfishing during spawning season. Peddlers or middle men developed, buying the fishermen's catch and then selling them in Utah and Salt Lake Counties (Carter 1959). Set line fishery with many hooks becomes popular for trouting. Gill netting was practiced but declared illegal by the Utah County Court (J. Procd. Utah County Court 1857, 1894). 114 Great Basin Naturalist Memoirs No. 5 Table 7 continued. Date" 1863 Activity Possible causes Jens Michelson begins long-term fishery, mouth of Spanish Fork River (Carter 1959). Serves south Utah Countv and market for fish oil. 1870 The fishing decline was noticed and a special committee was appointed in 1870 at the general conference of the LDS Church to develop fish culture (Popov 1949). 1870-1974 Change of inflowing waters quality; from cold, clear snowmelt to turbid warmer, more nutrient- rich waters (White et al. 1969). Return water from irrigated fields and cities warmer and higher in salt and silt load. Diversion of surface waters into irrigation, urban, and industrial use, then returned. 1872 Yarrow and Cope visited and felt the trout fishery had declined by about '/s. Several court cases on mesh size of siene and unlicensed fishermen. Fish traps must have free passage when not in use. The lake cutthroat esteemed above all other fish for flavor. Beginning of sports fishing in greater numbers (Cope and Yarn 1875). First dam built across Jordan River, beginning of lake level manipulations. Beginning of riverbed manipulations. Beaver dams destroyed, channelization, stream bank denuding becomes severe (Salt Lake Tribune 31 July 1932). More leisure time, larger population of younger people. 1875 Continued decline in catch, still a ready market. Utah Lake trout shipped to western (California) and eastern (Denver and Chicago) markets by railroad (J. Procd. Utah County Court 1894). 1876 Territorial legislature bans seining and poisons or explosives, and requires a fish passageway in all dams. Setlines reduced to 3 hooks per line (Utah Legislative Assembly 1876). Higher prices in out-of-state markets. Completion of Central Utah Railroad branch. Concern over decrease territorywide on fish, particularly Utah Lake trout. 1878 1880 First Utah County fish and game commissioner appointed (Utah Archives #25, 1940:279-80). Entrances of all irrigation canals should be screened (Utah Legislative Assembly 1880). 1880 Visit by David Starr Jordan, who described Utah Lake as universe's greatest sucker pond (Jordan and Gilbert 1881, Salt Lake Tribune 1923). General knowledge that irrigation practices were destroying many fish. Changing fish population, suckers gaining ascendency. 1882 1884 Lawful to fish with seine 200 yds long by 12 ft wide, mesh 2 inch center and IV2 inch in wings (Utah Legislative Assembly 1882). Me.sh size reduced IV2 in for 50 ft center. Compromise point for Utah Lake level reached (Utah Legislative Assembly 1884). Screen law for irrigation ditches repealed because a nuisance to clean screens. Carp introduced into Utah Lake (Utah Legislative Assembly 1886). Season established from 1 October to 1 June to legally seine or hook and line fish for trout. Set line fishing prohibited. However, it continued through 1930s on commercial scale. Still (1974) practiced by .some sports fishermen (Utah Legislative A.ssembly 1888). Complaint by Madsen and others. Result of years of haggling between Salt Lake and Utah Counties over lake level. Farmers win their view in territorial legislature. Concern over sharp decline in catch of trout. Was best way to catch large trout, bass, and catfish without sorting course fish. 1981 Utah Lake M ONOGRAPH 115 Talile 7 continued. Date" Activity Possible causes Territorial game warden appointed. Large mouth bass introduced into Utah Lake (Utah Legislative Assemblv 1890). 1890 No one enforced laws before. 1890-1894 Black bullheads, channel catfish introduced into Utah Lake (Popov 1949). 1893 C. F. Decker and Co. begins buying Utah Lake fish from Madsens. Sell from ice wagons to Salt Lake City markets (Scott 1951). 1894° Carp and large mouth bass common in seine hauls. People accept them and they become a regular part of commercial fishery. Still many .suckers and chubs (Popov 1949). 1894 Most trout shipped out of territory. Suit brought in Utah County court to halt practice (Utah County Court Journal 1894:186). Desire to improve fishing in Utah Lake. Economic demand, public desire shifts from dried and salted to fresh fish. Introduced species become acclimated and rapidly expand in numbers. Higher prices, desire for cash or out-of-territory credit. 1895 Large mouth bass become very common in Utah Lake; catch is 5:1, bass to trout, while suckers, chubs, and other common fish (carp?) are caught 18:1 to bass and trout {Deseret Evening News Jan 16, 1895). Decline of trout, large numbers of forage fish to feed bass. 1897 Only carp, chubs, mullets, and suckers can legally be taken by seine; however trout and large mouth bass can still be taken by hook and line then sold through 1904. Game wardens must accompany seiners. Legal net not to exceed 200 yds (Scott 1951). 1897 1897 Mills, factories, power plants, and manufacturing concerns required to install fish screens in intake canals (Utah Legislative Assembly 1897:94-95). Unlawful to seine within half mile of inflowing river into Utah Lake. Unlawful seines destroyed. Game warden had to go on every seining trip (Utah Legislative Assembly 1897). Approximately $133,496 wholesale fish sold from Utah Lake (estimate may be very low) (Carter 1969). Cutthroat population very reduced. Increased hook and line fi.shery for bass and trout. Reduce unnecessary destruction of fish (was not enforced strongly). Realization by public at large of need to recruit young fish each year to maintain fishery. Much unreported fishing occurred. 1899 Legal to ship certain fish out of Utah, including carp, chubs, suckers, black bullhead. D. S. Jordan again visits Utah Lake, finds fishery decline (Utah Legislative Assembly 1899). 1899-1904 Around 500,000 lbs of fi.sh from Utah Lake shipped out of state (Chambers 1910). 1900-1903 Channel catfi.sh and black bullheads introduced into Utah Lake (Popov 1949). 1900-1914 Increased catch of common fish, reaching 3,500,000 lbs live weight per year. Because many fish were between 3-5 lbs, 90 percent human consumption brought premium prices in eastern U.S. cities (Chambers 1910, Chambers 1913, Carter 1969). Market among eastern U.S. cities. To get needed out-of-state capital. Attempt to get more diversified fishery. Beef high in cost. European and Asian immigrants prized carp. 116 Great Basin Naturalist Memoirs No. 5 Table 7 continued. Date' Activity Possible causes 1900-1952 1903 1905 Gradual filling and dredging of mouth of Provo River eliminates varied habitats, reducing fish population (Loy 1972). Legal to catch and sell fish from Utah Lake by hook and line (Sharp 1897). Unlawful to catch trout commercially by any means (Utah Legislative Assembly 1903). Five Utah fish-selling businesses do $105,000 wholesale and $90,000 retail business within state of Utah. At least 10 percent (probably much more) came from Utah Lake (Carter 1969). Construction of more permanent docking and recreational facilities, and obtaining more farm land. Population decline continued. Good market for fish continues. 1905-19.30 1909 1909-1974 1910 1910-1920 1910-1974 1914, 1915, 19.30s 1914-1930 Sport fishery for large mouth bass becomes important (Carter 1969). Required commercial seining license cost varied from year to year ($1 to $25), usually $10. Royalty to state on fish seined, 15;s^ppe!»- Sii^\..^a. /v -'^m^MM. Fig. 4. Black-necked Stilt. Photo by R. D. Porter and R. J. Erwin. followed by the water level rising and flood- the years 1932-1942 the lake was at its low- ing plants that have invaded the dried-up est point ever recorded. In the 1961-1964 areas. In the past 45 years (1931-1976) there period the lake level lowered again but not have been two periods of low water. During as much as in the earlier period. 1981 Utah Lake Monoc;raph 139 In the mid 1930s Provo Bay was subjected to channelization. This resulted in the water being confined to narrow canals, with much of the area exposed. No attempt was made to maintain the channels or to install headgates to regulate the water flow because of protests by local conservation interests {Evening Her- ald, 15 April 1936:1,8). During this period farmers along the shore extended their graz- ing operations out into areas that 20 years before had been under water. Fence lines were extended out to contain the cattle, and considerable plant growth developed along the fence rows. In time the low-growing veg- etation was replaced by willows and poplars, which attained considerable size. On the banks along the canals, poplar and willow trees became niunerous. On the flat areas of Provo Bay and around Utah Lake brushy ex- panses of willow and tamarisk became estab- lished. In the 1940s, as the level of the lake rose, the willows and tamarisk were first to be in- undated. These partially submerged plants provided breeding habitat for Western Grebes, American Coot, Long-billed Marsh Wrens, Yellowthroats, Yellow-headed Black- birds, Red-winged Blackbirds, and other spe- cies. Since the banks along the canals were higher as the result of the dredged materials, the willows and poplars were out of water and continued to grow into the 1950s and 1960s. As the trees matured into large, well- formed structvires, they provided nesting hab- itat for the colonial Double-crested Cormo- rants and Great Blue Herons. In parts of Pro- vo Bay the thickets of willow and tamarask also provided habitat for Snowy Egrets, Black-crowned Night Herons, and White- faced Ibis. Colonies of these three species be- came very extensive with the availability of protected nesting areas. Along the east side of Provo Bay, about a mile south of the mouth of Hobble Creek and about the same distance north, two fairly extensive rows of trees developed along existing fence rows. The trees along the north were used by Great Blue Herons until they fell or were blown over. Those along the south were not used ex- tensively until the 1960s, when the trees at the western end (and in deeper water) were used by Double-crested Cormorants and those eastward in tlie row by Great Blue Herons. As the trees at the western end com- menced to die, rot, and fall over, the cormo- rants nested more in the eastern part of the row and encroached on the herons. At the present time (1980) cormorants and herons are using the remaining trees together, with some herons moving about a half mile north- ward to a very tall stand of trees barely at the water's edge. The status of the 200 species at the lake is not completely known. No doubt there is less nesting habitat around the lake now as com- pared to when the white man arrived in the valley in 1848. With a decrease in habitat and a great increase in use of the lake for rec- reation, there has probably been a decrease in number of birds that can utilize the lake and its environs for breeding, resting, and feeding. There is enough information at hand to discuss the population changes in about 20 species. White Pelicans have used Utah Lake as a food source as far back as we have records. They once nested here, as has been men- tioned, but no longer do so due to human harassment. They now nest on Gunnison Is- land in the Great Salt Lake and fly to Utah Lake for feeding and resting purposes only. The Double-crested Cormorant populations during the past 40 years have fluctuated con- siderably. Though numerous in the 1930s and 1940s, a decline occurred during the 1950s and 1960s. During the past decade there has been an increase in their numbers. Mitchell (1977) indicated that 54 percent of the known nesting colonies of cormorants in Utah occurred around Utah Lake. Great Blue Herons have been fairly numerous on a con- tinuous basis around the lake. The location of their colonies has changed as they have been subjected to the influence of man. Early re- ports indicated that they nested in the bul- rushes and a few nested in trees. Now, in the Utah Lake area, they nest almost exclusively in trees (see earlier reports). At Bear River Refuge, where their nesting habitat is pro- tected, they still nest in the bulrushes. Ha- rassment has probably been the major reason for the change in nesting habitat. A comparatively new arrival in Utah and the Utah Lake area is the Cattle Egret. The Great Basin Naturalist Memoirs Fig. 5. Common Snipe. Photo by R. J. Erwin. first record of the Cattle Egret at Utah Lake is 16 April 1971, when Hayward and Frost saw one in the wet meadow at the north Springville freeway exit (Hayward et al. 1976). From time to time since then one or more have been observed. During the sum- mer of 1976, three pairs were seen and be- lieved to have nested with a colony of Snowy Egrets south of the airport. Dennis Shirley, Utah State Division of Wildlife Resources, re- ported (pers. comm.) that in May 1980 about 25 Cattle Egrets nested with Snowy Egrets and Great Blue Herons in the same locality. For many years White-faced Ibis have been found around the lake where they feed in the wet meadows, but they were not known to breed here. In 1971 and 1972, Kaneko (1972) found a good-sized colony nesting in Provo Bay. They have been observed each year since then. Henshaw (1875) considered the Bald Eagle to be a permanent breeding species around the lake. Now this species is foimd here pri- marily in winter, and then only occasionally is it seen. Most of the wintering population is located in the arid valleys west of Utah Lake. Porter et al. (1973) concluded that the de- cline of the Peregrine Falcon in Utah was due to a combination of climatic changes and pesticide contamination. The Ring-necked Pheasant was introduced into the fields around Utah Lake in 1922, when a pheasant farm was commenced by the Division of Wildlife Resources (Cottam 1929b). The Chukar, another introduction by the Division of Wildlife Resources, was first released in Utah in 1936 (Hayward et al. 1976). A few have been observed around the airport dike from time to time. The Sandhill Crane formerly bred in suit- able marsh habitat around the lake and was known to breed in this area as late as 1939 (Bee and Hutchings 1942). At the present time this crane is a migrant in the Utah Lake area. The Common Gallinule has been re- ported from around the lake several times. In May 1969 Hayward saw three at Powell's Slough, and, due to their continued presence over a period of time and to their courtship behavior, considered them to be breeding (Hayward et al. 1976). The Long-billed Cur- lew, although still present in small numbers, is not as plentiful as it was 40 or 50 years ago. This decrease is due primarily to the re- 1981 Utah Lake Monograph 141 duction of its breeding habitat by man's use of the land. Cahfornia Gull populations are probably higher now than in pioneer times. Human ac- tivities have provided a greater variety of food sources than was present formerly. Plowed fields are a good source of insects, cherries are used as a food supply (Cottam 1935), and the ever-present city dump and land fill operations are used by gulls as a food source. Breeding areas are adequate to sus- tain a large population. Cottam (1935) and Beck (1942b) reported great numbers using Rock Island as a breeding ground. As the wa- ter level went up and the available area on Rock Island became smaller, the gulls moved to the dikes in the cooling ponds at the United States Steel Plant at Geneva on the east side of the lake. Yearly, thousands of gulls nest on the dikes, where they are near all the food sources mentioned. The Caspian Tern has not fared as well as the gulls. As long as there was an extensive land mass on Rock Island, gulls and terns were able to nest together there. As the land mass decreased in size, the terns were unable to compete with the gulls for nesting habitat, were preyed upon by the gulls, and so stopped nesting on the island. At the present time no colony of Caspian Terns is known to nest around the lake, although they still nest in the refuges around the Great Salt Lake. A number of the small song birds are more common now than they were before the set- tlement of the valley. Pasture and hay fields have provided greater habitat for the Mead- owlark. Plantings of trees and shnibs around homes and the development of city parks has increased the nesting habitat for the Ameri- can Robin, Black-headed Grosbeak, and House Finch. Barns, outbuildings, and bridges are used extensively by Barn and Cliff Swal- lows for nesting purposes. Henshaw (1875:2) specifically mentioned the Robin as being more abundant than when the settlers first arrived. The Blue Grosbeak is more common around the lake than formerly. Several have been observed in the vicinity of the lake over the past 15 years. This species is found more commonly in the southern and eastern parts of Utah. Two introduced species, the House Sparrow and Starling, are now common resi- dents of the lake environs. Sparrows were in- troduced into many parts of the United States and were reported in Utah prior to 1870 (Hayward et al. 1976). The Starling is a more recent arrival, first reported in the Utah Lake area during the winter of 1951-1952 (Behle 1954). Both species are very adaptable and have, in some instances, replaced the native bird fauna. Formerly the Common Crow was a sparse breeder around the lake. Bee and Hutchings (1942) and Richards and White (1963) reported a nest at the mouth of Hobble Creek in the month of May. Richards (1971) indicated that the eastern race Corviis brachyrhynchos brachyrhynchos is the sub- species found in the valley. At the present time the crow is a winter visitant, being found here from November through Febru- ary and March. Early Reports on Avian Species (1872-1905) As mentioned previously, the first recorded white men to observe bird life around Utah Lake were Dominguez and Velez de Esca- lante and their associates in 1776. During the next 100 years we know very little about bird life around the lake except for scattered statements in some of the pioneer diaries. In 1872, H. W. Henshaw and H. C. Yarrow ac- companied a geographical survey party that spent some time in Utah Valley in July and November and December. Henshaw (1875), in describing some of the ducks they saw and collected at Utah Lake, indicated that they were plentiful. He report- ed that [italics added] the borders of Utah Lake afford a home in summer for very rruiny of these ducks [Gadwall, p. 447]. In writing about the Cinnamon Teal, which he called the "Red-breasted Teal," he wrote In Utah, I learned from good authority that it breeds in great numbers, especially in the marshes of Utah Lake [p. 478]. He wrote about the Greater Blackhead [Greater Scaup] Among the hordes of ducks seen at Utah Lake in No- vember, the presence of this species was recognized and several were shot [p. 479], 142 Great Basin Naturalist Memoirs No. 5 % 1 K r,;; .■./.: ■•'■ ■AT:: '^ Fig. 6. Black Tern. Photo by R. J. Erwin and the Goldeneye visits the neighborhood of Utah Lake in great ahtin- dance during, the fall, and is, I think, a winter resident [p. 480]. The Red-breasted Merganser he considered rather common at Utah Lake in November, more so than either of its congeners [Hooded or Common Mer- gansers, p. 484]. The American Wigeon occurs in great ahtindame on Utah Lake during the fall, where it is found in considerable numbers even late in November, and, indeed, in the neighborhood of cer- tain warm springs and sloughs about Provo, more or less may find sufficient inducement to keep them all winter [p. 475]. Besides the ducks, Henshaw (1875) men- tioned the presence of a number of other spe- cies, which gives us a better picture of the bird Hfe around the lake over 100 years ago. His statements are as follows: Common Loon [called by Henshaw the Great Norther Diver] was said by fishermen of Utah Lake to be rather com- mon, remaining in their waters till quite late in the fall [p. 488]. Western Grebe is a coDwion species of Utah Lake in summer perhaps the most so of the family; and breeds here [p. 466]. White Pelicans [American Pelican] were seen at Utah Lake in July sf)aringhi [p. 485]. Great Blue Heron was seen on the borders of Utah Lake as late as December, and it probably remains there through the winter [p. 464]. 1981 Utah Lake Monograph 143 Fig. 7. Spotted Sandpiper. Photo by R. D. Porter Black-crowned Night Heron [Night Heron] White-faced Ibis [Glossy Ibis] appears to occur commonhj in Utah about the large lakes and marshes. As it was seen about Utah Lake in December, it probably is a resident [p. 466]. is well known to the gunners about Utah Lake under the name of "Black Snipe." It is said to be common in spring and fall, and may, I think, breed in this vicinity [p. 463] 144 Great Basin Naturalist Memoirs No. 5 Rough-legged Hawk [Black Hawk]: None were obtained until we reached Provo, where it was the most numerous of the hawks. Utah Lake and the surrounding marshes attract multitudes of waterfowl; and this undoubtedly explains in part the abundance of hawks at this season, since wounded and disabled ducks must form no inconsiderable part of their food [p. 426]. Bald Eagle [White-headed Eagle] is numerous in Utah, perhaps more so than is usual in the West, as the presence of several large lakes well stocked with fish attract it. It regularly visits the shores of Utah Lake from the adjoining mountains, where it finds opportunities for rearing its young undisturbed, within easy reach of the lake [p. 427]. Marsh Hawk was near Utah Lake, their numbers were scarcely less than were the Rough-legged Hawks [p. 416]. Ring-billed Gull is common on the larger bodies of water throughout Utah. Numbers were seen on the Provo River late in No- vember, when the lake was frozen over. They are with- out doubt winter residents here [p. 485]. Forster's Tern [Howell's Tern] was quite common at Utah Lake in the summer, where it breeds along the shores [p. 486]. Long-billed Marsh Wren: In the extensive marshes which border Utah Lake, and which are covered with a dense growth of coarse grasses and reeds, these wrens were exceedingly numer- ous; and, in breaking a path through the reeds, which often are so dense as to render progress well nigh impos- sible, hundreds of these little birds were startled up from their retreats, while their harsh notes were heard on all sides in expostulation. Almost as numerous as the birds themselves were their nests, which were seen on all sides, suspended on the tall, waving stems [p. 186]. Robin: At Provo, it was very common, where a few years since it was unknown; the advent of this, as of several other well known birds, following the occupation of the soil and its subsequent tillage by the settlers [p. 143]. Tree Sparrow: The species was found co7nmon at Provo in December [p. 277]. Bobolink: is a rather common bird in the fields about Provo, Utah, where the parent birds were noticed feeding their young July 25 [p. 311]. Common Crow met with only at Provo, where a number were seen at different times. Said by the settlers to have appeared within a few years [p. 327]. During the next 30 years there is a paucity of information concerning the bird life of Utah Lake. In 1892, H. C. Johnson, a resident of American Fork and an interested oologist, collected eggs of the following species of birds in Powell's Slough: Bittern, Blue- winged Teal, Snipe, Sora Rail, Coot, Long- billed Marsh Wren, and Yellow-headed Blackbird. The following year Johnson (1893) reported seeing a loon on the lake and col- lected eggs of the Bittern, Mallard, Wilson Snipe, Coot, Long-billed Marsh Wren, and Yellow-headed Blackbird. He also observed Great Blue Herons nesting in Springville Lake (Provo Bay) and stated that they were on an island which was simply covered with Great Blue Herons and we counted about 60 nests built flat on the tules (there being no trees in that part of the country). He found in the same locality nests of the Western and Eared Grebes. A decade later the Rev. S. H. Goodwin (1904) of Provo visited Rock Island in Utah Lake and reported that a colony of White Pelicans was nesting there. He estimated there were about 200 young on the island. He noted that California Gulls and Forster's Terns were residents of the island along with the pelicans. About the same time that the Rev. Good- win had visited Rock Island, A. O. Treganza of Salt Lake City visited a Western Grebe colony on Utah Lake. He collected a set of eggs that eventually became part of the egg collection of E. J. Court of Washington, D.C. Court loaned this set of eggs to Dr. R. W. Shufeldt, who was making a study of the eggs of loons and grebes. In 1914 Dr. Shufeldt published his findings and reported on the Western Grebe eggs collected by Tregenza: The colony of grebes, where these eggs were collect- ed, was located about two miles from the shore, and contained about one himdred nests. Some of the clutches were in advanced incubation. The eggs were collected on 29 May 1904. Recent Reports on Avian Species (1905-present) Cottam (1927), in an annotated list, men- tioned a number of species in and around the lake. The published account of his thesis 1981 Utah Lake Monograph 145 (Cottam 1929c) listed 72 water birds known to occur in Utah County. He regarded 29 as breeding birds, 33 as occurring in the winter, 39 as common migrants, and 15 as residents. These hsts were based on his field work, col- lected specimens, and from the literature. During this same period of time Cottam participated with the National Audobon So- ciety in their annual Christmas census of birds. The results (Cottam 1928, 1929a) showed that in 1928 his party saw 51 species and 1971 individuals and in 1929 they saw 59 species and 2588 individuals. Both surveys were in the lake area. Commencing in the 1930s and contining to the present, much has been written con- cerning the avifauna of the lake. Unfortu- nately this material is scattered in many pub- lications, where sometimes it is incidental to the main theme of the publication. Some ma- terial (field notes and observations) has been collected but has not been published. The fol- lowing brief summary of the literature from 1930 to the present will be given. For con- venience it has been arranged into three cat- egories: (1) Papers and reports published in nationally recognized journals and period- icals, (2) those found in periodicals of local interest and distribution, and (3) unpublished data. Two short notes by Allen (1936, 1937) in- dicate several species nested on the lake and state that pelicans were still being shot in- discriminately. C. Lynn Hay ward served as a warden for the National Audubon Society in 1936 (personal interview) and Reed Fautin, then a graduate student at Brigham Young University, carried on the warden patrol of pelicans, avocets, and long-billed curlews in 1937 (Allen 1937). Beck (1942a,b, 1943, 1947) added considerable information to the status of gulls on the lake. His 1942a paper indicated that six species of gulls frequented the lake, and the 1942b publication gave de- tailed observations of the breeding ecology of the California Gull on Rock Island. He esti- mated the 1942 postnesting population of gulls to be 68,744. His third paper described the plumage changes that occur in California Gulls from hatching to maturity. The 1947 report was a popular account of the 1942b publication on the breeding biology of the gulls (1942). Bee and Hutchings (1942) listed 47 species as nesting around the lake. Behle (1942, 1945, 1966) specifically mentioned a number of birds at Utah Lake. The 1942 and 1966 pa- pers listed one species each from the lake (Sanderling and Wood Duck). The 1945 pub- lication listed 13 species seen at Rock Island in 1932 and indicated that 6 species were nesting on the island at that time. Cottam (1941) reported collecting a LeConte's Spar- row near Utah Lake in December 1927 for the only collected specimen known for the state of Utah. During the spring and summer of 1937 Fautin (1940, 1941a,b) carefully stud- ied two colonies of Yellow-headed Blackbirds near the mouth of Provo River. His report gives a good ecological picture of this species at Utah Lake. Hayward (1935a,b, 1936, 1937, 1944, 1966) contributed a number of studies on the status of birds at Utah Lake. The 1935a paper gave information on the Caspian Tern for a six- year period (1927-1933) on Rock Island. His second paper compares bird life in Bear Lake and Utah valleys and mentions a few water birds at Utah Lake. The 1936 publication gives observations on 14 species of shore birds seen during the summer of 1936 at the lake. The remaining papers report the pres- ence of isolated species at the lake. Hayward, Cottam, Woodbury, and Frost (1976) contributed considerable information concerning the species found on and around the lake. Johnson (1935a,b) reported collecting two Snow Buntings near the mouth of Provo Riv- er. Kingery (1974, 1976) recorded the Com- mon Tern around the lake in April 1974 and June 1976. Lockerbie (1947) sighted two Brown Pelicans in a flock of White Pelicans on Utah Lake in April 1947. Mitchell (1975) reviewed the status of the Double-crested Cormorant in Utah and gave data on the col- onies around Utah Lake. Mitchell (1977) re- ported a study of the breeding biology of the Utah Lake Cormorants. Scott (1968) reported a Red Knot at Utah Lake 11 May 1968, the only report of this species for the lake. Webb's Christmas bird counts for the Audu- bon Society (1973b, 1974b, 1975a, 1976, 1977b, 1978c, 1979b) mentioned a number of species of water birds found at the lake dur- 146 Great Basin Naturalist Memoirs No. 5 ing the seven years mentioned. Four rare spe- cies reported at Utah Lake by Kingery (1977) were the Red-necked Grebe, White-winged Scoter, Sabine's Gull, and Common Grackle. Migrant species (Franklin Gull, Blue-gray Gnatcatcher, and Orange-crowned Warbler) lingering at Utah Lake into December 1977 were recorded by Kingery (1978). Among the publications of local interest and distribution are publications by the Divi- sion of Wildlife Resource, Utah Audubon So- ciety, and Mount Timpanogos Audubon Chapter of the National Audubon Society. Jensen (1974), in a section that deals with Utah County, gives information on land ownership and vegetative cover in the Provo and Goshen Bay areas of Utah Lake and also the hunter use and numbers of geese and ducks hunted in the county. The Utah Audubon Society, with head- quarters in Salt Lake City, has published for many years the Utah Audubon News. From 8 to 12 numbers have appeared each year, and many of the issues contain references to birds around Utah Lake. For a number of years an- nual field trips by the society were taken to many areas in the state. One of these annual trips was to Utah Lake and was reported in the Utah Audubon News. The number of in- dividual birds seen, as well as the different species observed, was recorded and gives a picture of the bird life around the lake. Cas- sal (1966), Ferris (1965), Geoghagen (1965), Kashin (1957, 1959, 1960, 1961, 1962, 1963, 1964), Lockerbie (1955a,b), Lockerbie and Behle (1952), Stone (1968), Tainter (1956), and Weissman (1968) published information on Utah Lake bird life. From these reports we know that a Great Blue Heron colony ex- isted in the north part of the lake from at least 1955 to 1962, since it is mentioned a number of times during this time period. The earliest is Lockerbie (1955a), who reported 21 herons standing in their nests in the spring of 1955. Kashin (1960) reported two Great Blue Heron colonies with a total of 50 nests. The Mount Timpanogos Chapter of the National Audubon Society, at Provo, Utah, has published since late in 1972 the Tim- panogos Honker, which has contained articles dealing with birds at the lake. Simmons (1974) reported the presence of a Cattle Egret at the lake in April 1974. Webb (1973a, 1974a, 1975b, 1977a, 1978a, 1979a, 1980) reported the results of several local Christmas bird counts with, in some in- stances, more information than appeared in the American bird accounts. Webb (1977c) observed a Mockingbird late in October 1977 at the lake. In December of the same year he (1978b) saw five species of shorebirds that normally migrate earlier in the season. Two anonymous reports (1978a,b) and short notes by Johnson and Webb (1977) and Monroe (1979) listed common species observed at the lake during field trips taken by the Mount Timpanogos Chapter of the Audubon So- ciety. Three sources of unpublished information on Utah Lake that contain valuable informa- tion are field notes, master's theses, and data cards on the egg collections in Monte L. Bean Life Science Museum at Brigham Young University. The field notes of R. G. Bee (1924-1962), C. L. Hayward (early 1930s-present), and H. H. Frost (1960-pres- ent) contain valuable notes on birds and some of the bird colonies around the lake. A number of master's theses deposited at Brigham Young University give further infor- mation on the bird life of the lake. Cottam's thesis (1927) was cited above. Murphy (1951) studied the birds wintering along the east shore of the lake south of the mouth of Provo River and adjacent to the Provo Airport (Oc- tober 1950-March 1951) and reported 24 species of passerine birds wintering in the area, including 21 winter visitants, 8 per- manent residents, 4 summer residents, and 2 migrants. Talley (1957) studied the nasal mites of overwintering Red-winged Black- birds and Brewer's Blackbirds found along the north shore of Provo Bay. Barnett (1964) studied the waterfowl nesting at Powell's Slough and found only 6 species. He con- cluded that lack of good marsh habitat, fluc- tuating water levels, and cattle and predator destruction of the nests were limiting factors in waterfowl production. He also listed the seasonal distribution of 26 other species that frequented the marsh. Kaneko (1972) report- ed the nesting of White-faced Ibis in the Pro- vo Bay area. This was followed by Mitchell's 1981 Utah Lake Monograph 147 Fig. 8. Wilson's Phalarope. Photo by R. J. Erwin. (1974) Study on the Double-crested Cormo- rant in the Provo Bay area and at Geneva Dike and Gunnell's (1976) study of the Snowy Egret in the same two locaHties. Ish- am (1975) discussed the spacial distribution of the nests of the Black-crowned Night He- ron and the Snowy Egret and obtained some of his data from the colonies in Provo Bay and at the Geneva Dike. Alford (1978) ob- tained some prenesting behavior data from a colony of White-faced Ibis located in the Provo Bay area of Utah Lake. Earlier in this century bird egg collecting was a popular avocation. Some of these col- lections were very well prepared and, in ad- dition to the eggs themselves, data were kept with each set of eggs indicating the date col- lected, general location, specific nesting habi- tat and, frequently, the nesting materials, and other bird species nesting in the same local- ity. BYU's Monte L. Bean Life Science Mu- seum has a number of collections made by in- dividuals in Utah that specifically designate Utah Lake as the collecting locale. This in- formation is very valuable in giving us a pic- ture of some of the nesting birds around the lake (see Table 2). Bird Populations at Utah Lake In summarizing the information found in the printed reports and the unpublished data, an understanding of the avifauna of Utah Lake emerges. Two hundred species of birds have been reported from the lake and its sur- roundings, representing 46 families (Table 2). Table 3 indicates the relative abundance of these species. The habitats around the lake have been placed into five groups. Many of the 200 spe- cies are not restricted to a single habitat but may be found in two or more areas. Table 4 shows the habitat preferences of the birds at the lake. 148 Great Basin Naturalist Memoirs Table 2. Birds of Utah Lake, their relative abundance, seasonal occurrence, and habitat preferences. No. 5 Abundance A Abundant— Will usually be seen C Common— May not be seen each time in the field U Uncommon— Will only be seen occasionally Ca Casual— Only seen once in great while R Rare— Reported only once or a very few times Seasonal Occurrence M Migrant M + Migrant, occasionally remaining in area PR Permanent resident SR Summer resident (75-100 percent of time) (25-75 percent of time) (10-25 percent of time) (less than 10 percent) (less than 1 percent) SR+ Summer resident, a few wintering WV Winter visitant Jan Month or season when only seen once "Breeding ° "Introduced Habitats Name Abundance Seasonal occurrence Open Marshy water land Beaches Wet meadow Dry meadow Family Gaviidae Common Loon Gavia immer Family Podicipedidae Red-necked Grebe Podiceps grisegena Horned Grebe Podiceps auritus R Ca May X X X X 'Eared Grebe Podiceps nigricoUis californicus SR X X '"Western Grebe Aechmophorus occidentalis SR- X X 'Pied-billed Grebe Podilymhus podiceps podiceps PR X X Family Pelecanidae "White Pelican Pelecanus erythrorhynchos Brown Pelican Pelecanus occidentalis SR Apr Family Phalacrocoracidae "Double-crested Cormorant Phalacrocorax auritus SR Family Ardeidae "Great Blue Heron Ardea herodias treganzai A-C SR- "Cattle Egret Bubulcus ibis ibis Ca SR Common Egret Casmerodius alhtis egretta "Snowy Egret Egretta thula brewsteri SR 1981 Table 2 continued. Utah Lake Monograph 149 Habitats Seasonal Abundance occurrence Open Marshy Wet Dry water land Beaches meadow meadow "Black-crowned Night Heron Nycticorax nyxticorax hoactli "American Bittern Botaurus lentiginosiis Family Ciconiidae Wood Stork Mycteria americana Family Threskiornithidae "White-faced Ibis Plegadis chihi Family Anatidae Whistling Swan Ohr columbianus Ca SR- SR- Summer SR WV "Canada Goose Branta canadensis White-fronted Goose Answer albifrons Snow Goose Chen caerulescens caeridescens Apr & Nov X "Mallard Anas platyrhynchos platyrhynchos Black Duck Anas riibripes "Gadwall Anas strepera •Pintail Anas acuta PR WV PR PR "Green-winged Teal Anas crecca carolinensis PR 'Blue-winged Teal Anas discors discors C-U "Cinnamon Teal Anas cyanoptera septentrionalium American Wigeon Anas americana SR- SR- "Northern Shoveler Anas clypeata Wood Diick Aix sponsa "Redhead Aythya americana SR Nov SR- 150 Table 2 continued. Great Basin Naturalist Memoirs No. 5 Name Seasonal Abundance occurrence Ring-necked Duck Aythija coUaris Canvasback Aijthija vaUsineria Greater Scaup Aythya marila nearctica Lesser Scaup Aythya offinis Ca C Ca SR M Habitats Open water Common Goldeneye Biicephahi clangula americana C wv X Barrow's Goldeneye Bucephala islandica Ca wv X Bufflehead Bucephala albeola C-U wv X Oldsquaw Ckmgala hyemaUs Ca M X White-winged Scoter Melanitta deglandi deglandi R Apr X "Ruddy Duck Oxyura jamaicensis C SR-I- X Hooded Merganser Mergus ciicidkitus U wv X Common Merganser Mergus merganser americanus u wv X Red-breasted Merganser Mergus serrator serrator C PR X Family Cathartidae Turkey Vulture Cathartes aura teter u SR Family Accipitridae Sharp-shinned Hawk Accipiter striatus velox Ca PR Cooper's Hawk Accipiter cooperii Ca SR Red-tailed Hawk Buteo jamaicensis U PR Swainson's Hawk Buteo swainsoni U PR Rough-legged Hawk Buteo lagopus sanctiphannis u WV Marshy Wet Dry land Beaches meadow meadow 1981 Table 2 continued. Name Ferruginous Hawk Butco regalis Utah Lake Monograph 151 Habitats Seasonal Open Abundance occurrence water Marshy land Wet Dry Beaches meadow meadow Golden Eagle Aqttila chnjsaetos PR Bald Eagle Haliaectus Icucocephahts 'Marsh Hawk Circus cijanetis liudsoniiis PR Family Pandionidae Osprey Pandion haliaetus caroUnensis Ca Family Faconidae Prairie Falcon Falco mexicantis Ca PR Peregrine Falcon Falco peregrinus Ca Merlin Falco cohimbahus Ca PR American Kestrel Falco sparverius sparverius PR Family Phasianidae °° ° Ring-necked Pheasant Phasianus colchicus PR '"Chukar Alectoris chukar PR Family Gniidae "Sandhill Crane Grus canadensis Family Rallidae "Virginia Rail Ralhis limicola limicola PR °Sora Porzana Carolina PR °?Common Gallinule Gallinula chloropiis cachinnaus Ca SR "American Coot Fulica americana americana Family Charadriidae Semipalmated Plover Charadrius semipabnatus Ca 152 Table 2 continued. Great Basin Naturalist Memoirs No. 5 Habitats Name Seasonal Open Marshy Wet Dry Abundance occurrence water land Beaches meadow meadow 'Snowy Plover Charadriiis alexandriniis nivosus SR 'Killdeer Charadriiis vocifenis vociferus PR Black-bellied Plover Pluvialis sqiiatarola Family Scolopacidae "Common Snipe Cappella gallinago delicata PR 'Long-billed Curlew Numeniiis americanus SR 'Spotted Sandpiper Tringa macularia C Solitary Sandpiper Tringa solitaria u Greater Yellowlegs Tringa melanoleuca c Lesser Yellowlegs Tringa flavipes c 'Willet C-U Catoptrophorus semipalmatus inornatus Red Knot R Calidris canutus rufa Baird's Sandpiper Calidris bairdi Ca Least Sandpiper Calidris mimitilla U Dimlin U Calidris alpina pacifica SR May Semipalmated Sandpiper Calidris pusilla Ca Western Sandpiper Calidris matiri Sanderling Calidris alba Long-billed Dowitcher Limmodromus scolopaceus Marbled Godwit Limosa fedoa 1981 Table 2 continued. Utah Lake Monograph 153 Name Habitats Seasonal Abundance occurrence Open water Marshy Wet Dry land Beaches meadow meadow Family Recurvirostridae "American Avocet Reciirvirostra americana "Black-necked Stilt Hiinantoptts mexicanus mexicaniis Family Phalaropodidae "Wilson's Phalarope Phalaropus tricolor Northern Phalarope Phalaropus lobatus Family Laridae Glaucous Gull Lams hyperboreus hyperboreus Herring Gull Larus argentatus smithsonianus "California Gull Larus californicus Ring-billed Gull Larus delawarensis SR SR Feb SR- WV Franklin's Gull Larus pipixcan Bonaparte's Gull Larus Philadelphia Sabine's Gull Xenia sabini sabini Ca Ca Ca SR Apr 'Forster's Tern Sterna forsteri Common Tern Sterna hirundo Ca SR "Caspian Tern Sterna caspia "Black Tern Chlidonias niger surinamensis Family Columbidae "Mourning Dove Zenaida macroura tnarginella Family Stigidae Screech Owl Otus asio SR Ca PR Great Horned Owl Bubo virginianus Ca 154 Table 2 continued. Great Basin Naturalist Memoirs No. 5 Habitats Name Seasonal Open Abundance occurrence water Marshy land Wet Dry Beaches meadow meadow Burrowing Owl Athene cttnicularia hypugaea "Long-eared Owl Asio otiis tiiftsi "Short-eared Owl Asio flammeus flammeus Family Caprimulgidae "Common Nighthawk Choredeiles minor Ca PR PR SR Family Apodidae Black Swift Cypseloides niger borealis Chimney Swift Chaetura pelagica Vaux's Swift Chaetura vauxi vaitxi Ca May May M White-throated Swift Aeronatites saxatalis Family Trochilidae Broad-tailed Hummingbird U Selasphorns platycercus platijcercus Family Alcedinidae Belted Kingfisher Ca Megaceryle alcyon caurina Family Picidae "Common Flicker C Colaptes auratus Lewis' Woodpecker Ca Asyndesinus lewis Hairy Woodpecker U Dendrocopos villosus Downy Woodpecker U Dendrocopos puhesceus leucurus Family Tyrannidae "Eastern Kingbird C Tyrannus tyranntts Western Kingbird C Tyrannus verticalis "Say's Phoebe U Sayornis saya "Willow Flycatcher C Empidonax trailli SR PR PR PR PR SR SR SR SR 1981 Table 2 continued. Utah Lake Monograph 155 Habitats Seasonal Abundance occurrence Open water Marshy Wet Dry land Beaches meadow meadow Gray Flycatcher Empidonax ivrightii Ca Western Wood Pewee Contopiis sordidulus Ca SR Family Alaudidae Horned Lark Eremophila alpestris Ca PR Family Hinmdinidae Violet-green Swallow Tachycineta thalossino lepida SR Tree Swallow Tachycineta bicolar SR Purple Martin Progne siibis Ca 'Rough-winged Swallow Stelgidopteryx ruficoUis SR "Bank Swallow Riparia riparia riparia SR X X 'Barn Swallow Hiriindo nistica erythrogaster X X Cliff Swallow Petrochelidon pyrrhonota SR Family Motacillidae Water Pipit Anthtis spinoletta Family Laniidae Loggerhead Shrike Lanius ludoviciantts SR- Northern Shrike Lanius excubitor invictits Ca Family Cinclidae Dipper Cinchis mexicamis unicolor Ca PR Family Troglodytidae Rock Wren Salpinctes obsolettis obsoletus "Long-billed Marsh Wren Cistothorus pahistris House Wren Troglodytes aedon parkmanii Ca 156 Table 2 continued. Great Basin Naturalist Memoirs No. 5 Name Seasonal Abundance occurrence Family Mimidae Mockingbird Mirnus polyglottos leucoptems Sage Thrasher Oreoscoptes montaniis Family Muscicapidae Mountain Bluebird Sialia currucoides Townsend's Solitaire Mijadestes totvnsendi townsendi Swainson's Thrush Catharus ustulatus Hermit Thrush Catharus guttatiis "American Robin Turdus migratorius propinquus Blue-gray Gnatcatcher Polioptila caerulea anioenissima Family Sylviidae Ruby-crowned Kinglet Regulus calendula cineraceus Family Paridae Black-capped Chickadee Parus atricapillus Family Emberizidae Snow bunting Plectrophenax nivalis nivalis "Song Sparrow Zonotrichia melodia Lincoln's Sparrow Zonotrichia lincolnii White-crowned Sparrow Zonotrichia leucophnjs Dark-eyed Junco Junco hyemalis Savannah Sparrow Amnwdramm sandwichensis he Conte's Sparrow Ammodramus leconteii Tree Sparrow Spizella arborea ochracae Ca U Ca Ca C U Ca Ca SR SR M M M PR SR PR WV PR M WV SR Habitats Open water Marshy land Beache Wet meadow Dry meadow 1981 Table 2 continued. Utah Lake Monograph 157 Habitats Name Seasonal Abundance occurrence Open water Marshy Wet Dry land Beaches meadow meadow Chipping Sparrow Spizella passerina arizonae Ca Vesper Sparrow Pooecetes graminetis Lark Sparrow Chondrestes gnimmacus sihgatus Ca SR age Sparrow Aimophila belli nevadensis SR Green-tailed Towhee Pipilo chlorurus Rufous-sided Towhee Pipilo erythrophthalmtis Ca SR PR Black-headed Grosbeak Ca Pheucticus melanocephalus melanocephalus Blue Grosbeak U Passerina caerulea interfusa SR Lazuli Bunting Passerina amoena Ca SR Western Tanager Piranga ludoviciana Family Pamlidae Orange-crowned Warbler VermiDora celata SR Nashville Warbler Vermivora ruficapilla ridgwayi Ca Virginia's Warbler Vermivora virginiae Ca SR "Yellow Warbler Dendroica petechia SR Black-throated Gray Warbler Dendroica nigrescens nigrescens Ca SR Townsend's Warbler Dendroica townsendi SR Yellow-rum ped Warbler Dendroica coronata "Common Yellowthroat Geothlypis trichas MacGillivray's Warbler Geothlypis tolmiei Ca 158 Table 2 continued. Great Basin Naturalist Memoirs No. 5 Habitats Seasonal Abundance occurrence Open water Marshy land Wet Dry Beaches meadow meadow Wilson's Warbler Wihonia piisilla Ca M 'amily Vireonidae Solitary Vireo Vireo solitariiis R May Warbling Vireo Vireo gilvus R May ^amily Icteridae Northern Oriole Icterus galbula C SR •Yellow-headed Blackbird Xanthocephaltis xanthocephalus C SR-I- ° Red-winged Blackbird Agelaius phoeniceus c PR "Western Meadowlark Sturnella neglecta c PR Common Crackle Quiscalus quiscula R Mar 'Brewer's Blackbird Euphagus cyanocephalus 'Brown-headed Cowbird Molothrus ater PR SR 'Bobolink Dolichonyx oryzivorus Family Fringillidae Pine Siskin Carduelis pintis pintis "American Coldfinch Carduelis tristis pallida Cassin's Finch Carpodacus cassinii House Finch Carpodacus mexicanus frontalis Evening Crosbeak Coccothraustes vespertinus brooksi Family Ploceidae *" "House Sparrow Passer domesticus doniesticus Ca Ca Ca SR PR SR PR PR Family Sturnidae °° "Starling Stumis vulgaris vulgaris PR 1981 Table 2 continued. Utah Lake Monograph 159 Name Family Corvidae Pinon Jay Gymnorhiniis cyanocephala Scrub Jay Aphelocoma coerulescens "Black-billed Magpie Pica pica hudsonia Common Crow Corvus brachyrhynchos Raven Corvus corax siniiatiis Habitats Seasonal Open Marshy Wet Dry Abundance occurrence water land Beaches meadow meadow Ca Ca PR WV PR The seasonal occurrence of the birds has been categorized into seven groups: (1) mi- grants, (2) migrants occasionally remaining in the area, (3) permanent residents, (4) summer residents, (5) summer residents that may oc- casionally winter, (6) winter visitants, and (7) those having been found only once or twice at the lake. It should be kept in mind that these categories apply to the birds at the lake and do not reflect their status in other parts of the state. For example, the Western Tan- ager is considered a migrant at the lake but in the state is a summer resident. Migrants are those birds that visit the lake usually twice a year as they pass to and from their breeding grounds. There are 37 species that have been assigned to that status (Table 5). There are 6 species that are migrants, but our records show that occasionally they may re- main here during the winter. These are the Solitary Sandpiper, Greater Yellowlegs, Less- er Yellowlegs, Least Sandpiper, Long-billed Dowitcher, and Marbled Godwit. Permanent residents are those found here all the year Table 3. Relative abundance of birds at Utah Lake. Relative abundance Species Percent Abundant Common Uncommon Casual Rare Total 10 5 76 37 44 22 55 27 19 9 204° around. There are 47 species of this type (Table 6). Summer residents are those that are here during the spring, summer, and fall. Frequently they cannot stand very cold weather or have food habits closely associ- ated with insects or other invertebrates not available during the colder parts of the year. Table 7 lists the 46 summer residents at Utah Lake. Occasionally, some summer residents may winter in the area, although most of their kind have left for more suitable habitats to the south. Twenty-eight species are in this category (Table 8). A few species spend their winter months here and then travel to other areas for breeding purposes. Twenty species are considered to be winter visitants (Table 9). Sixteen species have been recorded once or twice at the lake. They are usually rare visitors in the state as well as to the lake. The species in this group are the Red-necked Grebe, Brown Pelican, Common Egret, Wood Stork, White-fronted Goose, Wood Duck, White-winged Scoter, Red Knot, Her- ring Gull, Sabine's Gull, Black Swift, Chimney Swift, LeConte's Sparrow, Solitary Table 4. Habitat preferences of avian species at Utah Lake. Habitat Species Open water Marsh Beaches Wet meadow Drv meadow 67 101 40 128 115 'Several species listed i : than one category. 160 Great Basin Naturalist Memoirs No. 5 Vireo, Warbling Vireo, and Common Crackle. Table 10 summarizes this informa- tion. Sixty-eight species breed at Utah Lake (Table 11). The earliest breeding species commence egg laying in late March and early April and include Double-crested Cor- morant, Creat Blue Heron, Canada Goose, and House Sparrow. The peak of the nesting season is in the month of May with some late-breeding species extending into July (Fig.l). The late nesters are Snowy Plover, Kill- deer, Spotted Sandpiper, Mourning Dove, Willow Flycatcher, Yellow Warbler, Brown- headed Cowbird, Bobolink, and American Goldfinch. There are four species of birds that are not native to the area and are now part of the permanent resident population. They are the Ring-necked Pheasant, Chukar, House Spar- row, and Starling. Rock Island A unique feature of Utah Lake is Rock Is- land. It formerly provided a nesting and rest- ing habitat for a number of birds, but the ris- ing level of the water in the lake during the 1970s completely inundated the island. The yearly fluctuations of the lake now result in the island being visible during part of the year and then disappearing as the water rises. It is not known how long the island has exist- ed. Bee (1924-1962) mentioned the killing of pelicans on the island in 1890. Goodwin (1904:128) indicated that there were about 70- 68 65- 60- 58 55- r 50- 45- 40- 35- 34 30^ 25- 20- 15- 9 10- 5- 2 cm — May Jun Jul Fig. 10. Breeding chronology of birds at Utah Lake. Species counted in each month that they were found breeding. 200 young pelicans on the island in 1904, and added that they ranged in size "from a half grown gosling, to that of a large fowl and larger." Nothing was recorded about the is- land for the 25-year interval between Good- win's report and Cottam's (1929c) list of the water birds of Utah Lake. Cottam (1935) re- ported great numbers of California Gulls nesting on the island and that the colony had been on the increase for a number of years. Bee (1924-1962) and Hay ward (1936-pres- ent) report a number of visits to the island in the 1930s. Hay ward (19.35a) discussed the Caspian Tern colony on the island and re- ported that from 1927 to 1933 the tern colo- ny diminished in size as the California Gull colony increased. Beck (1942b) gave the best physical description of the island and also in- cluded an aerial photograph [p. 105]. He in- Table 5. Migrant species at Utah Lake. For scientific names see Table I. 1. Common Loon 2. Horned Grebe 3. Snow Goose 4. Greater Scaup 5. Lesser Scaup 6. Oldsquaw 7. Osprey 8. Sandhill Crane 9. Semipalmated Plover 10. Black-bellied Plover 11. Baird's Sandpiper 12. Dunlin 1.3. Semipalmated Sandpiper 14. Western Sandpiper 15. Sanderling 16. Northern Phalarope 17. Glaucous Gull 18. Bonaparte's Gull 19. Common Tern 20. Vaux's Swift 21. White-throated Swift 22. Lewis's Woodpecker 23. Purple Martin 24. Mountain Bluebird 25. Townsend's Solitaire 26. Swainson's Thrush 27. Hermit Thrush 28. Lincoln's Sparrow 29. Chipping Sparrow .30. Western Tanager 31. Nashville Warbler 32. Yellow-rumped Warbler 33. MacGillivray's Warbler 34. Wilson's Warbler ,35. Evening Grosbeak .36. Pinon Jay 37. Scrub Jay 1981 Utah Lake Monograph 161 dicated that there were four main plant com- munities on the island. Beck estimated that in a three-year period (1940-1942) the Califor- nia Gull population increased from 22,730 to 68,744. He considered this colony to be one of the largest California Gull colonies in the world. Behle (1945) visited Rock Island 26 May 1932 and reported 12 species of birds on the island at that time. Sugden (1947) report- ed nesting California Gulls on the island in May of 1945 and 1946. In six nests, he found an exotic egg in the gull's nest. Each of five nests had a pheasant egg besides the gull eggs, and one nest was found with a coot egg. In November 1951 a flock of 25 Snow Bun- tings were seen at Rock Island by Floyd Thompson. One was found dead and was pre- sumed to have been shot the previous day by a duck hunter (Lockerbie and Behle 1952). In 1957 Bee (1924-1962) reported 6 species of birds on the island in June and noted that the California Gulls had completed their nesting. Table 6. Permanent residents at Utah L^ke. For sci- entific name see Table 1. 1. Pied-bill Grebe 2. Mallard 3. Gadwall 4. Pintail 5. Green-winged Teal 6. Blue-winged Teal 7. Red-breasted Merganser 8. Sharp-shinned Hawk 9. Red-tailed Hawk 10. Swainson's Hawk 11. Golden Eagle 12. Marsh Hawk 13. Prairie Falcon 14. Peregrine Falcon 15. Merlin 16. American Kestrel 17. Ring-necked Pheasant 18. Chukar 19. Virginia Rail 20. Sora 21. Killdeer 22. Common Snipe 23. Screech Owl 24. Great Homed Owl 25. Long-eared Owl 26. Short-eared Owl 27. Belted Kingfisher 28. Common Flicker 29. Hairy Woodpecker 30. Downy Woodpecker 31. Horned Lark 32. Dipper .33. Rock Wren .34. Long-billed Marsh Wren 35. American Robin ■36. Ruby-crowned Kinglet 37. Song Sparrow 38. Rufous-sided Towhee .39. Red-winged Blackbird 40. Western Meadowlark 41. Brewers Blackbird 42. American Goldfinch 43. Cassin's Finch 44. House Sparrow 45. Starling 46. Black-billed Magpie 47. Raven Table 7. Summer residents at Utah Lake. For scien- tific name see Table 1. 1. White Pelican 2. Cattle Egret 3. Snowy Egret 4. Turkey Vulture 5. Cooper's Hawk 6. Common Gallinule 7. Snowy Plover 8. Spotted Sandpiper 9. Black-necked Stilt 10. Forster's Tern 11. Caspian Tern 12. Black Tern 13. Common Nighthawk 14. Broad-tailed Hummingbird 15. Eastern Kingbird 16. Western Kingbird 17. Say's Phoebe 18. Willow Flycatcher 19. Gray Flycatcher 20. Western Wood Pewee 21. Violet-green Swallow 22. Tree Swallow 23. Rough-winged Swallow 24. Bank Swallow 25. Barn Swallow 26. Cliff Swallow 27. House Wren 28. Mockingbird 29. Sage Thrasher 30. Savannah Sparrow 31. Vesper Sparrow 32. Lark Sparrow 33. Sage Sparrow .34. Green-tailed Towhee .35. Black-headed Grosbeak 36. Blue Grosbeak 37. Lazuli Bunting 38. Virginia's Warbler 39. Yellow Warbler 40. Black-throated Gray Warbler 41. Townsend's Warbler 42. Common Yellowthroat 43. Northern Oriole 44. Brown-headed Cowbird 45. Bobolink 46. Cassin's Finch 162 Great Basin Naturalist Memoirs No. 5 He mentioned the presence of Forster's Terns and Black Terns, but no Caspian Terns. It has been only in the last three or four years that the island has been completely inundated. As the lake recedes, in years to come it may once more become an area that birds may use. The increased use of the lake as a recrea- tional area with larger numbers of motor boats may result in the area being less useful to wildlife than it has been in the past. The foregoing reports indicate that 18 species of birds have been observed on the island. The breeding and nonbreeding species are listed in Table 12. During the years 1940-1944, Vasco M. Tanner and other members of the Depart- ment of Zoology at Brigham Young Univer- sity banded young California Gulls on Rock Island. Regular aluminum U.S. Fish and Wildlife bands were used plus red- and yel- low-colored bands in various combinations to distinguish the years the birds were banded. A total of 2316 birds were banded, and of this number 128 were reported as being seen, captured, or found dead, a 5.5 percent recov- Table 8. Summer residents that may occasionally winter at Utah Lake. For scientific names see Table 1. 1. Eared Grebe 2. Western Grebe 3. Double-crested Cormorant 4. Great Blue Heron 5. Black-crowned Night Heron 6. American Bittern 7. White-faced Ibis 8. Canada Goose 9. Cinnamon Teal 10. American Wigeon 11. Northern Shoveler 12. Redhead 1.3. Canvasback 14. Ruddy Duck 15. FerRiginous Hawk 16. American Coot 17. Long-billed Curlew 18. Willet 19. American Avocet 20. Wilson's Phalarope 21. California Gull 22. Franklin's Gull 23. Mourning Dove 24. Burrowing Owl 25. Loggerhead Shrike 26. Blue-gray Gnatcatcher 27. Orange-crowned Warbler 28. Yellow-headed Blackbird ery of the banded birds (Tanner 1941, 1947, Tanner and Beck 1942). Table 13 summarizes the banding data for the four-year period. The Future of Utah Lake Human impact will continue to be a factor affecting the avifauna of the lake. The degree of impact can be great or small depending upon the manner in which Utah Lake will be managed in the future. The lake will remain a multipurpose unit involved in furnishing water to Salt Lake Valley, providing a recre- ational area, supporting populations of wild- life, and being an object of beauty and in- spiration to those who appreciate the wonders of nature. At the present time no one agency or organization is actively in- volved in looking at the lake as a whole and considering its many uses. The lake water users have their objectives and aims in mind Table 9. Winter visitants at Utah Lake. For scientific names see Table 1. 1. Whistling Swan 2. Black Duck 3. Ring-necked Duck 4. Common Goldeneye 5. Barrow's Goldeneye 6. Bufflehead 7. Hooded Merganser 8. Common Merganser 9. Rough-legged Hawk 10. Bald Eagle 11. Ring-billed Gull 12. Water Pipit 13. Northern Shrike 14. Black-capped Chickadee 15. Snow-Bunting 16. White-crowned Sparrow 17. Dark-eyed Junco 18. Tree Sparrow 19. Pine Siskin 20. Common Crow Table 10. Seasonal occurrence of birds at Utah Lake. Status Number Percent Migrants Migrants that occasionally winter Permanent residents 37 6 47 19 3 24 Summer residents 46 23 Summer residents that occasionally winter Winter visitants 28 20 14 10 Occasional visitants 16 200 8 1981 Utah Lake Monograph 163 Table 11. Nesting species at Utah Lake. For scientific names see Table 2. Nests during Mar Apr May Jun 1. Eared Grebe 2. Western Grebe - 3. Pied-billed Grebe — 4. White Pelican 5. Double-crested Cormorant 6. Great Blue Heron 7. Cattle Egret 8. Snowy Egret 9. Black-crowned Night Heron - 10. American Bittern - — 11. White-faced Ibis -- 12. Canada Goose — - 13. Mallard 14. Gadwall - 15. Pintail — 16. Green-winged Teal - — 17. Blue-winged Teal — 18. Cinnamon Teal — - 19. Northern Shoveler — 20. Redhead - 21. Ruddy Duck — - 22. Marsh Hawk -- " 23. Ring-necked Pheasant 24. Sandhill Crane 25. Virginia Rail - - " 26. Sora 27. Common Gallinule 28. American Coot 29. Snowy Plover — 30. Killdeer -- 31. Common Snipe 32. Long-billed Curlew -- -- — - .33. Spotted Sandpiper .34. Willet .35. American Avocet 36. Black-necked Stilt -- .37. Wilson's Phalarope .38. California Gull .39. Forster's Tern 40. Caspian Tern 41. Black Tern 42. Mourning Dove — 43. Long-eared Owl — 44. Short-eared Owl 45. Common Night Hawk 46. Common Flicker 47. Eastern Kingbird "" ""' 48. Say's Phoebe 49. Willow Flycatcher 50. Rough-winged Swallow — 51. Bank Swallow 52. Bam Swallow — 53. Long-billed Marsh Wren — 54. American Robin 55. Song Sparrow 56. Yellow Warbler - — ' 57. Common Yellowthroat - - - Jul 164 Table 11 continued. Great Basin Naturalist Memoirs No. 5 Nests during Mar Apr Jun Jul 58. Yellow-headed Blackbird 59. Red-winged Blackbird 60. Western Meadowlark 61. Brewer's Blackbird 62. Brown-headed Cowbird 6.3. Bobolink 64. American Goldfinch 65. House Sparrow 66. Starling 67. Black-billed Magpie 68. Common Crow Table 12. Birds of Rock Island, Utah Lake, Utah. For scientific names see Table 1. Breeding species Nonbreeding species 1. White Pelican 2. Canada Goose .3. Mallard 4. Pintail 5. Killdeer 6. Spotted Sandpiper 7. California Gull 8. Forster's Tern 9. Caspian Tern 10. Black Tern 11. Song Sparrow 1. Double-crested Cormorant 2. Snowy Plover 3. Willet 4. Sanderling 5. American Avocet 6. Snow Bunting 7. Yellow Warbler Table 13. Banding results of California Gulls at Rock Island, Utah Lake, Utah, 1940-1944. Mexico NV ID UT WY 1 1 1 28 1 2 57 1 No. British Baja Year banded Columbia WA OR CA California 1940 1,000 2 10 1941 1,000 1 5 4 12 1 1942 .300 1 1944 16 Total ;coveri( 44 82 2 Total 2,316 22 128 as do the municipalities that border the lake and the Division of Wildlife Resources, who by state law are responsible for the wildlife in, on, and around the lake. Shall each agency continue to follow its course of action without consulting or being aware of the ob- jectives of other involved parties? To do so would cause, in time, utter chaos as the de- mands of each agency upon the lake become greater. Careful consideration needs to be given now to the multifaceted nature of Utah Lake. Some of the problems concerned with the management of the lake are briefly men- tioned. Conservative projections of population growth in Utah and Salt Lake Valleys in- dicate that many more thou.sands of people will be living here by the year 2000. More people will necessitate the continued up- grading of wastewater plants in the various communities so that water quality will be maintained in the lake. Increased population will mean increased use of the lake for irriga- tion, industry, culinary purposes, fishing. 1981 Utah Lake Monograph 165 Marsh Hawk. Photo by R. J. Erwin. boating, waterskiing, picnicking, and hunt- ing. Some of these recreational needs are being provided by the Utah Lake State Park at the mouth of Provo River and the marinas being developed by the cities of American Fork and Orem. Provo City has been contemplating an in- crease in the number and length of runways at the Provo Airport to accommodate larger aircraft. One proposal is to increase the run- ways southward into the Provo Bay area. The Bureau of Reclamation has as part of the Central Utah Project the diking and draining of Provo and Goshen Bays to reclaim land and reduce evaporation from the lake. As the population of Salt Lake Valley increases, their demands for water for irrigation, in- dustry, and culinary use will become greater. The Division of Wildlife Resources is con- cerned with how the greater use of the lake will affect its wildlife. These problems and many others need to be considered. Can all the demands put upon the lake be satisfied? Should the airport run- ways be extended into the nesting habitat of ducks, geese, and colonial water birds? Is more land and water more important than breeding habitat for wildlife? Can Salt Lake Valley drain from the lake level without con- sidering the needs for recreation and other interests in Utah Valley? Should the Division of Wildlife Resources develop wildlife man- agement areas to protect and provide more breeding and resting habitat? Should private organizations such as the Audubon Society or other groups be encouraged to develop wild- life sanctuaries? Should more marinas be con- structed for increased boating and associated activities? Is there a way that all the groups inter- ested in Utah Lake can function together so that a unified plan may be formulated— not an agency that would dictate what should be done, but one that would bring interested groups together so that an interplay of ideas, objectives, and plans could be discussed and problems resolved? Fortunately, there is such an agency available. In 1973 the Utah State Legislature enacted the Provo-Jordan River Parkway Authority (State Lands 1973). This legislation became part of the Utah Code An- notated Section 65-10-1 and is as follows: There is created within the department of natural re- sources a division to be known as the Provo-Jordan River parkway authority and the board of the Provo-Jordan River parkwav authority for the purpose of estabUshing and coordinating programs for the development of rec- Great Basin Naturalist Memoirs No. 5 reational areas, water conservation, flood control, rec- lamation, and wildlife resources on or along the Provo and Jordan Rivers and their tributaries. Does Utah Lake fit into this legislation? Considerable discussion has been carried on concerning this question, and the answer is that Utah Lake is an integral part of the Pro- vo-Jordan River parkway plan. The problems that confront us at the pres- ent time need to be discussed and resolved for the sake of Utah Lake. The sooner the in- terested parties can be brought together and made aware of all the problems, the sooner they may be solved. Utah Lake is too valu- able an asset to be allowed to deteriorate or be exploited by one group over another. Only cooperation and consideration by all parties can solve the problems that confront us at this time. Literature Cited Alford, E. H. 1978. Early nesting by White-faced Ibis in relation to habitat: an adaptive advantage. Un- published thesis, Brigham Young Univ., Provo, Utah. 42 pp. Allen, R. P. 1936. On behalf of the White Pelican. Bird- Lore 38(5):355-356. 1937. White Pelicans, Avocets and Sickle-bills. Bird-Lore 39(5):365. Anonymous. 1978a. Bobolinks. Timpanogos Honker 9(5):2. 1978b. Notes. Timpanogos Honker 9(5):4. Barnett, L. B. 1964. An ecological study of waterfowl habitat at Powell's Slough, Utah Lake. Unpub- lished thesis, Brigham Young Univ., Provo, Utah. 45 pp. Beck, D. E. 1942a. Notes on the occurrence of gulls at Utah Lake. Great Basin Nat. 3(2):54. 1942b. Life history notes on the California Gull. No. 1. Great Basin Nat. 3:91-108. 1943. California Gull, A comparative plumage study. Great Basin Nat. 4:57-61. 1947. The seagull in Utah. Utah Magazine 9(4):22-25, 43-47. Bee, R. G. 1924-1962. Unpublished field notes. Brigham Young University Life Science Museum, Provo, Utah. Bee, R. G., and J. Hutchings. 1942. Breeding records of Utah birds. Great Basin Nat. 3(3-4):61-90. Behle, W. H. 1942. Records of the Herring Gull, Sand- erling and Lark Bunting in Utah. Condor 44:2.30-231. 1945. Water birds observed at Rock Island, Utah Lake in 1932. Great Basin Nat. 6(1-4):127-128. 1954. Changing status of the Starling in Utah. Condor 56(l):49-50. 1966. Noteworthy records of Utah birds. Condor 68(4):396-397. Cassel, V. 1966. Field trip to Utah County. Utah Audu- bon News 18(6):38-40. 15 May. Chavez, A., translator, and T. J. Warner, ed. 1976. The Dominguez-Escalante journal, their expedition through Colorado, Utah, Arizona, and New Mexi- co in 1776. Brigham Young Univ. Press, Provo, Utah. 203 pp. CoTTAM, C. 1927. Distributional list of the birds of Utah. Unpublished thesis. Department of Zoolo- gy, Brigham Young Univ., Provo, Utah. 164 pp. 1928. Christmas census— Provo, Utah. Bird-Lore 30(1):65. 1929a. Christmas census— Provo, Utah. Bird-Lore 31(l):61-62. 1929b. The status of the Ring-necked Pheasant in Utah. Condor 31(3): 117-123. 1929c. A study of the water birds of Utah Coun- ty, Utah. Proc. Utah Acad. Sci. 6:8-11. 19.35. Unusual food habits of California Gulls. Condor 37(3): 170-171. 1941. LeConte Sparrow in Utah. Condor 43(2): 116-1 17. CouES, E., AND H. C. Yarrow. 1875. Report upon the collection of mammals made in portions of Ne- vada, Utah, California, Colorado, New Mexico, and Arizona. During the years 1871, 1872, 1873, and 1874, in Report upon geographic and geolog- ical explorations and surveys west of the one-hun- dredth meridian in charge of First Lt. George M. Wheeler, Corps of Engineers U.S. Army. Vol. 5 (Zoology). Evening Herald. 19.36. Drainage of Mud Lake is pro- tested. Provo, Utah. 15 April: 1,8. Fautin, R. W. 1940. The establishment and mainte- nance of territories by the Yellow-headed Black- bird in Utah. Great Basin Nat. 1(2):75-91. 1941a. Development of nestling Yellow-headed Blackbirds. Auk 58(2):215-232. 1941b. Incubation studies of the Yellow-headed Blackbird. Wilson Bull. 53(2): 107- 122. Ferris, R. 1965. Utah and Juab County field trip. Utah Audubon News 17(6):22-24. Frost, H. H. 1960-Present. Unpublished field notes. Brigham Young University Life Science Museum. Provo, Utah. Geoghegan, E. 1965. Regular field trip to Utah Lake and environs, Sunday, May 9, 1965. Utah Audu- bon News 17(6):24. Goodwin, S. H. 1904. Pelicans nesting at Utah Lake. Condor 6(4): 126- 129. Gunnell, G. L. 1976. The Snowy Egret (Egretta thiila brewsteri): A life history study at Utah Lake with comments on the subspecies status. Unpublished thesis, Brigham Young Univ., Provo, Utah. 93 pp. Hayward, C. L. 1935a. The breeding status and migra- tion of the Caspian Tern in Utah. Condor 37(,3):140-144. 19.35li. A study of the winter bird life in Bear Lake and Utah Lake Valleys. Wilson Bull. 47(4):278-284. 1936. Some observations on shore birds at Utah Lake during the summer of 1936. Proc. Utah 1981 Utah Lake Monograph 167 Acad. Sci., Arts, Lett. 13:191-193. 1936-Present. Unpublished field notes. Brigham Young University Life Science Museum. Prove, Utah. 1937. Some new and unusual bird records from Utah. Wilson Bull. 49(4):303-305. 1944. Additional records of uncommon birds in Utah. Condor 46(4):204-205. 1966. New and unusual bird records from Utah. Condor 68(3):305-306. Hayward, C. L., C. Cottam, A. M. Woodbury, and H. H. Frost. 1976. Birds of Utah. Great Basin Nat. Mem. 1:1-129. Henshaw, H. W. 1875. Report upon the ornithological collections made in portions of Nevada, Utah, California, Colorado, New Mexico and Arizona during the years 1871, 1872, 1873, and 1874. Chapter 3, pages 131-508, 977-987, in Report upon geographic and geological explorations and surveys west of the one-hundredth meridian. Vol. 5 (Zoology). IsHAM, R. S. 1975. The spacial distribution of the nests of the Black-crowned Night Heron (Nycticorax nycticorax) and the Snowy Egret (Leucoplwyx thula) in central Utah. Unpublished thesis. Brig- ham Young Univ., Provo, Utah. 52 pp. Jensen, F. C. 1974. Evaluation of existing wetland habi- tat in Utah. Utah State Division of Wildlife Re- sources Publication, No. 74-17. Federal Aid Proj- ect W117 L-D-R C4. 219 pp. Johnson, D. E. 1935a. Some bird notes from Utah. Wil- son Bull. 47(2): 160. 19.35b. Another Snow Bunting record for Utah. Wilson Bull. 47(4) :294. Johnson, H. C. 1892. A trip on Utah Lake. Ornithologist andOologist 17(7): 104. 1893. A Utah egging trip. Ornithologist and Oo- logist 18(7): 101-103. Johnson, R., and M. Webb. 1977. Bird sightings. Tim- panogos Honker 7(3): 1. Kaneko, K. D. 1972. Nesting of the White-faced Ibis (Plegadis chihi) on Utah Lake. Unpublished thesis, Brigham Young Univ., Provo, Utah. 84 pp. Kashin, G. 1957. The May trip to Provona Beach and Saratoga Springs. Utah Audubon News 9(6):24-25. 1959. Trip to Provona Beach and Saratoga Springs. Utah Audubon News ll(6):34-35. 1960. Field trip to Utah Lake. Utah Audubon News 12(7):33-34. 1961. Trip to Utah Lake. Utah Audubon News 13(6):5-6. 1962. Field trip to Utah Lake. Utah Audubon News 14(5):30-31. 1963. Field trip to Utah Lake. Utah Audubon News. 15(6):36-37. 1964. Trip to Utah Lake. Utah Audubon News. 16(6):42. Kingery, H. E. 1974. Mountain West. American Birds 28(4):832-836. 1976. Mountain West. American Birds 30(5):982-985. 1977. Movmtain West. American Birds 31(5):1027-1031. 1978. Mountain West. American Birds 32(3):.380-.384. Lockerbie, C. W. 1947. Utah region. Audubon Field Notes 1(4):161-162. 1955a. Side-light of the Easter field trip. Utah Audubon News 7(5):27-28. 1955b. The May field trip to Provona Beach and Saratoga Springs. Utah Audubon News 7(6):33-34. Lockerbie, C. W., and W. H. Behle. 1952. Field Notes. Utah Audubon News 4(3): 17. Mitchell, R. M. 1974. Nesting ecology of the Double- crested cormorant (Phalacrocorax auritus auritus) on Utah Lake. Unpublished thesis. Brigham Young Univ., Provo, Utah. 103 pp. 1975. The current status of the Double-crested Cormorant in Utah: a plea for protection. Ameri- can Birds 29(5):927-930. 1977. Breeding biology of the Double-crested Cormorant in Utah Lake. Great Basin Nat. 37(1): 1-23. Monroe, F. 1979. Field trip report. Timpanogos Honker 9(7): 1-2. Murphy, J. R. 1951. Ecology of passerine birds winter- ing at Utah Lake. Unpublished thesis, Brigham Young Univ., Provo, Utah. 63 pp. Porter, R. D., C. M. White, in collaboration with R. J. Erwin. 1973. The Peregrine Falcon in Utah, em- phasizing ecology and competition with the Prairie Falcon. Brigham Young Univ. Sci. Bull., Biol. Ser. 18(1): 1-74. Richards, G. L. 1971. The Common Crow, Corvus bra- chyrhynchos, in the Great Basin. Condor 73(1):116-118. Richards, G. L., and C. M. White. 1963. Common Crow nesting in Utah. Condor 65(6): 530-531. Scott, O. K. 1968. Great Basin, Central Rocky Moun- tain Region. Audubon Field Notes 22(4):560-562. Shufeldt, R. W. 1914. On the oology of the North American pygopodes. Condor 16(4): 169-180. Simmons, D. G. 1974. You should have been there. Tim- panogos Honker 3(2):5-6. State Lands. 1973. Chapter 182. Provo-Jordan River Parkway Authority Senate Bill No. 121. Passes 8 March 1973, in effect 8 May 1973. Stone, B. 1968. Provo Boat Harbor-May 19, 1968. Utah Audubon News 20(7): 10. Sugden, J. W. 1947. Exotic eggs in nests of California Gulls. Condor 49(3):93-96. Talley, G. M. 1957. The incidence of nasal mites in over-wintering Red-winged Blackbirds in the vi- cinity of Utah Lake, Utah. Unpublished thesis. Brigham Young Univ., Provo, Utah. 13 pp. Tainter, F. 1956. Provona Beach and adjacent fields yield big count on May field trip. Utah Audubon News 8(6):22-23. Tanner, V. M. 1941. Gull banding notes at Utah Lake. Great Basin Nat. 2(2):98. 1947. Gull banding at Utah Lake No. 3. Great Basin Nat. 8(l-4):37-39. 168 Great Basin Naturalist Memoirs No. 5 Tanner, V. M., and D. E. Beck. 1942. Gull banding notes at Utah Lake No. 2. Great Basin Nat. 3(2):55-57. Webb, M. 1973a. Winter bird count. Tinipanogos Hon- ker 2(2):4. 1973b. Christmas Bird Count— Provo, Utah. American Birds 27(2):479. 1974a. 1973 bird count. Tinipanogos Honker 3(1):3. 1974b. Christmas Bird Count-Provo, Utah. American Birds 28(2):488. 1975a. Christmas bird count— Provo, Utah. Amer- ican Birds 29(2):530. 1975b. Christmas bird census 1975. Timpanogos Honker 3(1.3):2. 1976. Christmas bird count— Provo, Utah. Ameri- can Birds 30(2):553-554. 1977a. Christmas bird count results 1976. Tim- panogos Honker 7(1):2. 1977b. Christmas bird count— Provo, Utah. Amer- ican Birds 31(4):817-818. 1977c. Late summer visitor. Timpanogos Honker 7(5):2. 1978a. Christmas bird count results. Timpanogos Honker 8(2):3 1978b. Results of the 1977 Christmas bird count. Timpanogos Honker (No volume number):2. 1978c. Christmas bird count— Provo, Utah. Amer- ican Birds 32(4):822. 1979a. Provo bird count. Timpanogos Honker. 8(12): 1,3. 1979b. Christmas bird count— Provo, Utah. Amer- ican Birds 3.3(4):620-621. 1980. Provo Christmas bird count. Timpanogos Honker (No volume number):3. Weissman, N. 1968. Provo river trip— May 19. Utah Audubon News 20(6):4-5. 1981 Utah Lake Monograph 169 AUTHOR AND TITLE INDEX FOR THE UTAH LAKE MONOGRAPH Aquatic and semiaquatic vegetation of Utah Lake and its bays, p. 68. Barnes, James R., and Thomas W. Toole, ar- ticle by, p. 101. Brimhall, Willis H., and Lavere B. Merritt, article by, p. 24. Brotherson, Jack D., article by, p. 68. Fishes of Utah Lake, p. 107. Frost, Herbert H., Clyde L. Pritchett, and Wilmer W. Tanner, article by, p. 128. Fuhriman, Dean K., Lavere B. Merritt, A. Woodruff Miller, and Harold S. Stock, article by, p. 43. Geology of Utah Lake: implications for re- source management, p. 24. Grimes, Judith A., Samuel R. Rushforth, Lar- ry L. St. Clair, and Mark C. Whiting, article by, p. 85. Heckmann, Richard A., and Lavere B. Mer- ritt, article by, p. 1. Heckmann, Richard A., Charles W. Thomp- son, and David A. White, article by, p. 107. Hydrology and water quality of Utah Lake, p. 43. Jackson, Richard H., and Dale J. Stevens, ar- ticle by, p. 3. Macroinvertebrate and zooplankton commu- nities of Utah Lake: a review of the lit- erature, p. 101. Merritt, Lavere B., and Willis H. Brimhall, article by, p. 24. Merritt, Lavere B., and Richard A. Heck- mann, article by, p. 1. Merritt, Lavere B., Dean K. Fuhriman, A. Woodruff Miller, and Harold S. Stock, article by, p. 43. Miller, A. Woodniff, Dean K. Fuhriman, La- vere B. Merritt, and Harold S. Stock, article by, p. 43. Physical and cultural environment of Utah Lake and adjacent areas, p. 3. Phytoplankton of Utah Lake, p. 85. Preface, p. 1. Pritchett, Clyde L., Herbert H. Frost, and Wilmer W. Tanner, article by, p. 128. Rushforth, Samuel R., Larry L. St. Clair, Ju- dith A. Grimes, and Mark C. Whiting, article by, p. 85. St. Clair, Larry L., Samuel R. Rushforth, Jud- ith A. Grimes, and Mark C. Whiting, article by, p. 85. Stevens, Dale J., and Richard H. Jackson, ar- ticle by, p. 3. Stock, Harold S., Dean K. Fuhriman, Lavere B. Merritt, and A. Woodruff Miller, ar- ticle by, p. 43. Tanner, Wilmer W., Clyde L. Pritchett, and Herbert H. Frost, article by, p. 128. Terrestrial vertebrates in the environs of Utah Lake, p. 128. Thompson, Charles W., Richard A. Heck- mann, and David A. White, article by, p. 107. Toole, Thomas W., and James R. Barnes, ar- ticle by, p. 101. White, David A., Richard A. Heckmann, and Charles W. Thompson, article by, p. 107. Whiting, Mark C, Samuel R. Rushforth, Lar- ry L. St. Clair, and Judith A. Grimes, article by, p. 85. NOTICE TO CONTRIBUTORS Original manuscripts in English pertaining to the biological natural history of western North America and intended for publication in the Great Basin Naturalist should be directed to Brigham Young University, Stephen L. Wood, Editor, Great Basin Naturalist, Provo, Utah 84602. Those intended for the Great Basin Naturalist Memoirs should be similarly directed, but these manuscripts are not encumbered by a geographical restriction. Manuscripts. Two copies of manuscripts are rer^uired. They should be typewritten, double spaced throughout on one side of the paper, with margins of at least one inch on all sides. 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