NOAA TR NMFS SSRF-670 NOAA Technical Report NMFS SSRF-670 I U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service I I OCT 1 9 1973 I Woods Hole, Mass. | Unharvested Fishes in the U.S. Commercial Fishery of Western Lake Erie in 1969 Ir HARRY D. VAN METER SEATTLE, WA JULY 1973 NOAA TECHNICAL REPORTS National Marine Fisheries Service, Special Scientific Report-Fisheries Series The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic distribution of fishery resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resources. NMFS is also charged with the development and implementation of policies for managing national fishing grounds, develop- ment and enforcement of domestic fisheries regulations, surveillance of foreign fishing oflf United States coastal waters, and the development and enforcement of international fishery agreements and policies. NMFS also as- sists the fishing industry through marketing service and economic analysis programs, and mortgage insurance and vessel construction subsidies. It collects, analyzes, and publishes statistics on various phases of the industry. The Special Scientific Report — Fisheries series was established in 1949. The series carries reports on scien- tific investigations that document long-term continuing programs of NMFS, or intensive scientific reports on studies of restricted scope. The reports may deal with applied fishery problems. The series is also used as a medium for the publication of bibliographies of a specialized scientific nature. NOAA Technical Reports NMFS SSRF are available free in limited numbers to governmental agencies, both Federal and State. They are also available in exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwi.se noted) from NOAA Publications Section, Rockville, Md. 20852. Recent SSRF's are: 619 JIacrozooplankton and small nekton in the coastal waters off Vancouver Island (Canada) and Washington, spring and fall of 1963. By Donald S. Day, January 1971, iii + 94 pp., 19 figs., 13 tables. 620 The Trade Wind Zone Oceanography Pilot Study. Part IX : The sea-level wind field and wind stress values, July 1963 to June 1965. By Gunter R. Seckel. June 1970, iii -p 66 pp., 5 figs. 621 Predation by sculpins on fall chinook salmon, Oncorliynclius tsliawytsclia, fry of hatchery or- igin. By Benjamin G. Patten. February 1971, iii -f 14 pp., 6 figs., 9 tables. 622 Number and lengths, by season, of fishes caught with an otter trawl near Woods Hole, Massa- chusetts, September 1961 to December 1962. By F. E. Lux and F. E. Nichy. February 1971, iii -)- 15 pp., 3 figs., 19 tables. 623 Apparent abundance, distribution, and migra- tions of albacore. Tliiutiins alahinga, on the North Pacific longline grounds. By Brian J. Rothschild and Marian Y. Y. Yong. September 1970, v -|- 37 pp., 19 figs., 5 tables. 624 Influence of mechanical processing on the quality and yield of bay scallop meats. Bv N. B. Webli and "F. B. Thomas. April 1971, iii -|- 11 pp., 9 figs., 3 tables. 625 Distribution of salmon and related oceanographic features in the North Pacific Ocean, spring 1968. By Robert R. French, Richard G. Bakkala, Ma- sanao Osako, and Jun Ito. March 1971, iii -|- 22 pp.. 19 figs., 3 tables. 626 Commercial fi.shery and biology of the fresh- water shrimp, Macrobrachium, in the Lower St. Paul River, Liberia, 1952-53. Bv George C. Miller. February 1971, iii -f 13 pp., 8 figs., 7 tables. 627 Calico scallops of the Southeastern United States, 1959-69. By Robert Cummins, Jr June 1971, iii -f 22 pp., 23 figs., 3 tables. 628 Fur Seal Investigations, 1969. By NMFS, Ma- rine Mammal Biological Laboratory. August 1971, 82 pp., 20 figs., 44 tables, 23 appendix A tables, 10 appendix B tables. 629 Analysis of the operations of seven Hawaiian .skipjack tuna fishing vessels, June-August 1967. By Richard N. Uchida and Ray F. Sumida. March 1971, v -f 25 pp., 14 figs., 21 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - 35 cents. 630 Blue crab meat. I. Preservation by freezing. July 1971, iii + 13 pp., 5 figs., 2 tables. II. Effect of chemical treatments on acceptability. By Jurgen H. Strasser, Jean S. Lennon, and Fred- erick J. King. July 1971, iii -|- 12 pp., 1 fig., 9 tables. 631 Occurrence of thiaminase in some common aquat- ic animals of the L'nited States and Canada. By R. A. Greig and R. H. Gnaedinger. July 1971, iii -f 7 pp., 2 tables. 632 An annotated bibliography of attempts to rear the larvae of marine fishes in the laboratory. By Robert C. May. August 1971, iii -|- 24 pp., 1 ap- pendix I table, 1 appendix II table. For sale by the Superintendent of Documents, U.S. Govern- ment Printing Office, Washington, D.C. 20402 - 35 cents. 633 Blueing of processed crab meat. II. Identification of some factors involved in the blue discoloration of canned crab meat Callinectes sapidus. Bv Melvin E. Waters. May 1971, iii + 7 pp., 1 fig"., 3 tables. 634 Age composition, weight, length, and sex of her- ring, Clnpea pallasii, used for reduction in Alas- ka, 1929-66. By Gerald M. Reid. July 1971, iii + 25 pp., 4 figs., 18 tables. 635 A biI)liography of the blackfin tuna, Thunnus atlanticiis (Lesson). By Grant L. Beardsley and David C. Simmons. August 1971, 10 pp. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - 25 cents. Continued on inside back cover. ^^^g^ ^.^^^^^^c ^ '"'WfNT Of U.S. DEPARTMENT OF COMMERCE Frederick B. Dent, Secretary NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION Robert M. White, Administrator NATIONAL MARINE FISHERIES SERVICE NOAA Technical Report NMFS SSRF-670 Unharvested Fishes in the U.S. Commercial Fishery of Western Lake Erie in 1969 HARRY D. VAN METER SEAHLE, WA JULY 1973 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, DC. 20402 - Price 25 cents The National Marine Fisheries Service (NMFS) does not approve, rec- ommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication furnished by NMFS, in any advertising or sales pro- motion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. CONTENTS Page Introduction 1 The commercial fishery 2 Commercial landings in 1969 3 Estimated catches by haul seines and trap nets 5 Haul seine estimates 6 Trap net estimates 7 Potential catches 9 Haul seine catches 10 Trap net catches 10 Combined catches 10 Conclusions 10 Acknowledgments 10 Literature cited 11 Figures 1. Western basin of Lake Erie 2 2. Typical trap net lift 3 3. Haul seine being brought ashore 3 4. Bagging haul seine for removal of catch 3 5. Total fish yield by months in U.S. waters of the western basin for haul seines and trap nets, 1969 5 6. Percentage contributions of high-, medium-, and low-value fish in the landed, discarded, and total catches estimated for haul seines and trap nets, April-November 1969 7 Tables 1. Total fish yield from Lake Erie in 1969 4 2. Total fish yield from the western basin of Lake Erie in 1969 4 3. Total fish yield by gear from the western basin of Lake Erie in 1969 5 4. Catch and percentage composition of the catch in 14 seine hauls in Sandusky Bay, April-November 1969 6 5. Catch and percentage composition of the catch from 226 trap net lifts in U.S. waters of the western basin, April-November 1969 8 6. Projection of the commercial yield from haul seines and trap nets in U.S. waters of the western basin in 1969 8 111 Unharvested Fishes In the U.S. Commercial Fishery of Western Lake Erie in 1969' HARRY D. VAN METERS ABSTRACT Potential commercial fish production was estimated for U.S. waters of western Lake Erie in 1969 from pounds landed and pounds discarded. Periodic observations of catches in haul seines and trap nets revealed that about 37% of the catch (by weight) in haul seines and 26% of that in trap nets were low-value fishes that were discarded. Projection of these discarded catches to include the total fishing effort indicated that an additional 2.8 million lb of low- value species would have been landed in 1969 if a reasonable profit had been assurred. It is concluded that the sustained yield could be increased considerably with only a moderate in- crease in fishing effort. INTRODUCTION A .sizable percentage of the U.S. commercial fish catch in western Lake Erie is discarded and returned to the lake each year because market demand is lacking or the profit margin is too small. As early as 1955, the Bureau of Com- mercial Fisheries (now the National Marine Fisheries Service) investigated new markets for underutilized fish from Lake Erie (Premetz, 1956). Emphasis in earlier years was on the development of markets in the fur farm and pet food industries as outlets for such low-value species as freshwater drum {Aplodinotus grun- niens), gizzard shad {Dorosoma cepedianum.) , carp (Cyprinus carpio) , and go\dfish (Carassins aurahis)'. Recently, certain commercial inter- ests have explored the possibility of using these fish for fish meal and other industrial products. Greater market expansion is not the real crux of the problem confronting the fishermen today. Rather, there is a need to develop low-cost meth- ods of harvesting and processing the less de- sirable species in sufficient volume to provide a competitive product in existing markets. ' Contribution 469, Great Lakes Fishery Laboratory, U.S. Fish and Wildlife Service, Ann Arbor, MI 48107. ' U.S. Fish and Wildlife Service, Sandusky Biological Station, Sandusky, OH 44870. ' Common and scientific names of fishes mentioned in the text are those adopted by Bailey (1970). A questionnaire survey in the 1950's revealed that Ohio commercial fishermen believed that the potential annual production of low-value species was more than 25 million lb. They es- timated that 15 million lb were available in Sandusky Bay alone (Jones, 1960). These fig- ures are still quoted by fishermen and biologists, in the absence of specific data on population den- sities of Lake Erie fishes. In 1969 I attempted to determine the mag- nitude and species composition of the discarded portion of the U.S. catch from the principal gears employed in the western basin of Lake Erie. Data were collected on landed and dis- carded catches from 14 seine hauls in Sandusky Bay and 226 trap net lifts off Bono and San- dusky, Ohio. Catch data were then compared with the 1969 commercial production from the western basin and projected to estimate the po- tential take of these unharvested fish and the loss of revenue through lack of market demand or a suitable profit margin. Several Lake Erie species, including walleye (Stizostedion vitreum vitreum), yellow perch (Perca flavescens), white bass (Morone chry- sops) , and channel catfish (Ictalurus pnnctatus) , are taken by both the commercial and sport fish- eries in the w-estern basin. Other select species sometimes caught by commercial gear are classi- MICHIGAN Mon roe OHIO Figure 1. — Lake Erie is morphometrically separated in- to three basins. The small, shallow western basin shown here has a surface area of about 1,300 square miles. For compiling commercial production, the basin is di- vided into fishery statistical districts. Canadian waters are represented by district OE-1; Ohio waters by dis- tricts 0-1 (open lake), 0-4 (Sandusky Bay), and 0-5 (in- land tributary waters) ; and Michigan waters by a single district. fied as game and panfish and are excluded from the commercial harvest; these include primarily coho salmon (Oncorlujnchus kisutch) , small- mouth bass (Micropterus dolomieui) , rock bass (Ambloplites rupestris) , black crappie (Pomox- is nigromaculatus), white crappie {Pomoxis annularis), bluegill (Lepomis macrochirus) , green sunfish {Lepomis cyanellus) , and pump- kinseed (Lepomis gibbosus) . These fish, which were counted and weighed but omitted from the catch estimates in the present study, made up less than 0.2 Sc of the total weight of all fish caught in the seine hauls and trap net lifts observed. THE COMMERCIAL FISHERY The western basin of Lake Erie has long been considered to have the most valuable spawning and nursery grounds in the entire lake (Lang- lois, 1954). It makes up only 13^r of the lake area and has an average depth of less than 25 ft (Fig. 1). The comparatively warm waters of this basin, together with the extensive shoal areas around the many islands, provide ideal fishing grounds for many species of fish. How- ever, the long-term effects of environmental deg- radation, heavy exploitation, and the introduc- tion of new species — e.g., carp, goldfish, and rainbow smelt (Osmerus mordax) — have greatly changed the composition of the catch through the years (Applegate and Van Meter, 1970). Historically, the fishery has depended on such high -value fishes as the cisco (Coregonus arte- dii), lake whitefish {Coregonus clupeaformis) , blue pike {Stizostedion vitreum glaucum) , and walleye. Of these, only the walleye is of com- mercial importance in Lake Erie today, and it is in jeopardy. Since 1957 successful hatches have been produced in the western basin at only 3- or 4-year intervals, and the year classes have been heavily fished before they reached maturity. The result has been an all-time low in produc- tion and standing crop. Even with more strin- gent regulations today, the walleye faces a struggle for survival because of deteriorating environmental conditions in the lake. The year-class success of medium-value fishes — yellow perch, white bass, and channel catfish — is also fluctuating more widely from year to year than in the 1950's. The immediate future of the yellow perch, the mainstay of Lake Erie production for the past decade, is of major con- cern despite record landings in 1969. In eff"ect, a maiority of the year's production was com- prised of the exceptionally strong 1965 year class of perch that is about to phase out of the fishery. Landings in 1970 declined sharply and future landings are expected to continue this downward trend until another strong year class is produced. On the other hand, several low-value species have flourished and are greatly underexploited because the profit margin is small and the market demand unsteady. Few low-value fish are sold in the retail fresh-fish market although certain low-value species bring as much as 6(' per pound to the haul seiners when sold alive to pond own- ers who charge a fee for fishing. This market, however, is largely restricted to the spring sea- son because fish mortalities during holding and transport are prohibitively high in warm v/eath- er. Although most low-value species can be sold as mink and pet food at 2(' per pound, the fish- ermen are unable to show a profit at this price. Consequently, many tons are discarded and re- turned to the water. Freshwater drum, carp. l''i'4urc' '-!. A typical ti'a|j net lift in I'.S. watiM-- nf the western basin. Depth of trap net opening may range from 10 to 30 ft. Figure 3. — A haul seine, about 1,200 yd long, being brought ashore. This net is set in a semicircle off of barge towed by a boat. and goldfish, for example, are landed only at times when more valuable species are not being caught. In fact, fishermen often relocate their nets or stop fishing entirely in areas where the less desirable species are abundant. The main types of fishing gear currently em- ployed in western Lake Erie are gill nets in Canadian waters, and trap nets (in the open lake) (Fig. 2) and haul seines (Figs. 3 and 4) (in the shallower shoreline and bay areas) in U.S. waters. Stringent regulations in recent years have practically eliminated the use of gill nets in U.S. waters of western Lake Erie. Of great importance to the fishery of the western basin is shallow Sandusky Bay, located between the mouth of the Sandusky River and the open lake (Fig. 1) . It is about 15 miles long and averages about three miles wide, has an area of about 36,000 acres, and averages 6 to 8 ft deep. Although fish can move freely be- tween the lake and bay, haul seines, which are the major gear used in the bay, take a higher proportion of low-value fishes throughout the year than are taken by either haul seines or trap nets in the lake. COMMERCIAL LANDINGS IN 1969 The commercial yield for all of Lake Erie in 1969 was over 59 million lb (Table 1), or about 10 million lb higher than the average for 1913- 68 (Baldwin and Saalfeld, 1962, plus supplement, Figure 4. — Bagging the haul seine for removal of the catch. Frequently most of the catch is discarded. 1970). The 1969 Canadian landings reached a record high of 48 million lb (about 81 ''r of the total lake harvest) compared with U.S. landings of 11 million lb (19''^)'. Ohio fishermen har- vested about 9.5 million lb, or 86 '^r of the U.S. total and 16% of the lakewide catch. The 1969 commercial landings in the western basin totaled some 16.4 million lb or nearly 28^.^ of the lakewide catch (Table 2); Ontario con- tributed about 50*"^, Ohio 46''r, and Michigan 4"";-. Sandusky Bay, which makes up less than 4Sf of the area of the western basin, accounted ' The 1969 statistics were obtained directly from the several State and Provincial agencies that administer the Lake Erie fishery. Table 1. — Total fish yield (pounds) from Lake Erie in 1969. Category, and species Michigan Ohio Pennsyl- vania New York Total, United States Canada Lake total High value Walleye 47,161 139,302 4.793 91.304 282,560 192,591 475,151 Whlteflsh, Cisco 3 746 147 8 904 1,417 2,321 Other?'-' 2 9 29 40 1,549 1.589 Medium value Yellow perch 111,815 2 ,660,536 479,446 112,709 3,364,506 29 ,801,833 33,166,339 White bass 57.213 1 ,155,867 2.563 3.043 1.218,686 874,840 2,093,526 Channel catfish 21,144 713,465 744 673 736.026 101,513 837,539 Othersi' 1,003 1,003 98,840 99,843 Low value Freshwater drum 39,885 1. ,992,877 2,992 24,532 2,060,286 339,377 2,399,663 Bullheads 472 35,030 32 2 35,536 19,448 54,984 Rainbow smelt 464 1.399 310 2.173 15 ,075,522 15,077,695 Buffalo, quillback 9,151 46,544 55.695 55,695 Carp 431,785 2, ,586,849 788 351 3,019.773 189,531 3,209,304 Goldfish, carp X goldfish 98,912 98,912 98,912 White sucker, redhorse 25,374 110,200 3,876 33,272 172,722 16,317 189,039 Othersl-' 77 625 702 21,449 22,151 Mixed scrapi' 1 .291,769 1,291,769 Total all species 744.005 9, ,540,869 496,789 267.861 11,049,524 48 ,025,996 59,075,520 Others: high value— blue pike, northern pike, sturgeon, sauger; medium value— rock bass, crappies and other panfishes; low value — mctoneye, burbot, American eel, bowfin. 2/ — Upidentlfied (most were reportedly freshwater drum). Table 2. — Total fish yield (pounds) from the western basin of Lake Erie in 1969. Category, and species Michigan Ohio (Districts 0-1, 0-4, 0-5) Total, United States Canadian waters (District OE-1) Total western basin High value Walleye 47,161 132,766 179.927 165,208 345,135 Whitefish, Cisco 3 4B5 488 425 913 Otherffi^ 2 2 383 385 Medium value Yellow perch 111,815 921,641 1,033,456 6 ,640,111 7,673,567 White bass 57,213 1,058,626 1,115,839 685,110 1,800,949 Channel catfish 21,144 695,994 717,138 74,597 791,735 Othersi' 185 185 Lou value Freshwater drum 39,885 1,854,367 1,894,252 30,595 1,924,847 Bullheads 472 34,864 35,336 35,336 Rainbow smelt 209 209 12,419 12,628 Buffalo, quillback 9,151 46,241 55,392 55,392 Carp 431.785 2,559,486 2,991,271 81,192 3,072,463 Goldfish, carp X goldfish 98,912 98,912 98,912 White sucker, redhorse 25.374 86,503 111,877 3,550 115,427 Others^' 32 32 32 Mixed seraph' 519,185 519,185 Total all species 744.005 7,490,126 8,234,131 8 ,212,960 16,447,091 Others: high value — ^blue pike, northern pike, sturgeon, sauger; medium value — rock bass, crappies and other panfishes; low value — mooneye, burbot, American eel, bowfin. ■ Unidentified (most were reportedly freshwater drum). Figure 5. — Total fish yield by months in U.S. waters of the western basin for haul seines (solid line) and trap nets (broken line) in 1969. No fish were taken in January and February. (Table 3) . Three types, however, accounted for 92 Si- of the fish produced: Small-mesh gill nets took over 6.9 million lb, haul seines 5.7 million, and trap nets 2.-5 million. Although regulations that govern the fishing seasons vary among the states and the Province of Ontario, fishing normally begins in late March and ends about mid-December, depending on ice conditions. The fishing season in the Ohio waters of Lake Erie is administratively sep- arated into a spring and a fall fishery. The haul seine fishery produced over 68% of the U.S. catch in the western basin in 1969 and the trap net fishery nearly BOS'- . Production in the seine fishery was highest during late April and early May, and steadily declined as the season pro- gressed (Fig. 5). Production in the trap net fishery was also highest in April and May; after a summer lull, it increased again in the fall. for more than 20 Tr of the total landings. Since the late 1940's the bay has been the most heavily fished district in Ohio, if not in the entire lake. In 1948-53, Sandusky Bay fishermen landed an average of 58.5 lb of fish per acre, compared with an average of 9.1 lb per acre for other Ohio waters of Lake Erie (Chapman, 1955). In 1969, Sandusky Bay yielded 95.4 lb of fish per acre, compared with an average of 2.7 lb for Ohio waters of the open lake. The entire western basin yielded an average of 19.8 lb per acre and the entire lake about 9.3 lb per acre. At least seven types of commercial gear were fished in the western basin of Lake Erie in 1969 ESTIMATED CATCHES BY HAUL SEINES AND TRAP NETS Commercial fishermen remove their catch from haul seines and trap nets with long-handled dip nets (an average of 20 to 30 lb of fish are taken per di]i) . The fish are quickly sorted after each dip and unwanted fish returned to the water. Fish to be kept are separated according to species and boxed, or placed in holding pens if destined for the live-fish market. During trips to the fishing grounds, observers estimated the weight of the fish taken in each dip of the net and kept a running tally of total Table 3. — Total fish yield (pounds) by gear from the western basin of Lake Erie in 1969. Gear United Stat es Canada Total Pounds I Pounds X Pounds X Small-mesh gill net 4.299 Tri' 6 906,041 84 6,910,340 42 Haul seine 5.609,172 68 103,968 1 5,713,140 35 Trap net 2,436,868 30 103,705 1 2.540,573 15 Large-mesh gill net 18,270 Ir 834,989 10 853,259 5 Pound net - - 232,207 3 232,207 1 Trot line 130.247 2 32,050 Tr 162,297 1 Fyke net 35,275 Tr - ~ 35,275 Tr Total 8,234.131 - 8 212,960 - 16,447,091 ~ •'Tr . <0.5I. Table 4. — Catch (pounds and percentage) and (in parentheses) percentage com- position of the catch in 14 seine hauls in Sandusky Bay, April-November 1969. Estimati sd Ea tlmated catch Estimated weight Category, and species total catch Pounds X of discarded fish of landed fish Pounds ' , X of :otal catch Pounds % % of total catch High value Walleye 103 Tri' 43 Tr (42) 60 Tr (58) Medium value Yellow perch 304 Tr 149 Tr (49) 155 Tr (51) Vhite bass 1,217 1 337 1 (28) 880 2 (72) Channel catfish 6,454 8 4,460 12 (69) 1,994 4 (31) Subtotal 7,975 9 4,946 14 (62) 3,029 6 (38) Low value Freshwater drum 48,332 56 13,483 37 (28) 34,849 71 (72) Carp 8,700 10 810 2 (9) 7,890 16 (91) Goldfish, carp X goldfish 17,610 21 14,330 39 (81) 3,280 7 (19) Bullheads 22 Ir 5 Ir (23) 17 - (77) White sucker, rei Jhorse 405 1 232 1 (57) 173 Tr (43) Buffalo, quillback 84 Tr 34 Tr (40) 50 Tr (60) Gizzard shad, ali ewife 2,640 3 2,640 7 (100) — — — Subtotal 77,793 91 31,534 86 (41) 46,259 94 (59) Grand total 85,871 - 36,523 -- (43) 49,348 -- (57) -'Tr - <0.5%. estimated weight for each species and of the estimated weight or percentage of each that was discarded. Errors in estimation were min- imized by comparing the tallies of estimated landings with the quantities of boxed fish. As a further check (for trap net catches only), the actual weight of the landed catch of each species recorded in the fish house at the end of the day was compared with the poundage estimated by the observer. The percentage error in the esti- mated catches ranged from + 10 9f to — 16% for individual trips; however, the total weights of the estimated landings from all 13 series of trap net lifts combined averaged only 4% above the actual landings. Errors in estimation for seine catches could not be readily checked because the landings from more than one seine haul were often combined and reported as a day's catch. Estimates by observers of the landed and discarded portions, however, were compared with estimates by an experienced foreman to corroborate the pound- age estimates for each haul observed. Haul seine estimates Catch data wei'e collected at one of the San- dusky Bay seining grounds every two or three weeks fi'om April to November 1969. Esti- mated weight of a haul seine ranged from a low of 1,372 lb (July 28) to a high of 14,250 lb (.June 23). A total catch estimate of 8.5,871 lb was recorded for the 14 seine hauls, with an average of 6,134 lb (Table 4). Weight of the landed fish averaged 3,525 lb per haul (57C; of the total catch) and the discarded portion, 2,609 lb (43% ) . Some of the discards, however, were fish of high- and medium-value species that were released because they were below legal size. When undersized fish were excluded, the discard- ed catch that could have been legally kept aver- aged 2,252 lb per haul — or about 37% of the haul seine catches. Low-value species made up 91 ''r of the total catch by haul seines — 94 "^r of the landed catch and an estimated 86% of the discarded catch (Fig. 6). Freshwater drum made up most of the total catch and landed catch (Table 4). Gold- fish and carp also contributed significantly to the total catch. Carp were not as abundant as gold- fish in the total catch but contributed a higher portion of the landed fish because of the greater marketability of carp. Medium-value fishes provided over 9''^ of the total catch from the bay area — 6% of the landed fish and 14''r of the estimated weight of dis- 01 a. 100 80 60 40 20 Haul seines Trap nets Value category ^ High H Medium ^ LOW Landed Discarded Total Landed Discarded Total Figure 6. — Percentage contributions of high-, medium-, and low- value fish in the landed, discarded, and total catches estimated for haul seines and trap nets, April-November 1969. carded fish (all of the discarded fish were below legal size). Channel catfish provided the bulk of the catch of medium-value species. The high- value fishes (represented solely by the walleye) accounted for only 0.1 ''r of the estimated total catch, as well as of the landed and discarded catch. The walleye is not commonly taken in the bay except in early spring during upstream spawning migration to the Sandusky River. The value of the catch from the 14 seine hauls averaged $167 per haul, calculated from pre- vailing prices of fish paid to fishermen at the time of capture. The potential worth of the dis- carded fish averaged $45 per haul if the value for meal or related industrial uses is considered to be 2''- per jiound. The seine fishery, which takes primarily freshwater drum, carp, and goldfish, is in a favorable position to increase income through a greater production of low- value fishes. Even now the haul seiners, with operations requiring little overhead or main- tenance of gear and only limited hand labor, occasionally land and market sizable quantities of fish for as little as 2 to S( per pound. More- over, a majority of the seiners appear interested in increasing their landings of low-value fishes for sale to a steady and dependable buyer, even at this low price. Trap net estimates Tallies of the estimated catches were recorded on 13 trips (226 trap net lifts) to the fishing grounds in the open waters of the western basin from April to November 1969. The number of trap nets checked per trip ranged from 10 to 35 and averaged 17.4. The number of nets lifted on a given day usually depended on the catch of higher value species, i.e., the higher the catch of high- and medium-value fish, the smaller the number of nets lifted. In essence, it amounted to a self-imposed catch quota on the more select species to prevent a market glut that causes lower prices for succeeding catches. The total catch estimates from a single day's operation ranged from a high of 15,615 lb (May 28) to a low of 2,700 lb ( September 3) . Catches were usually largest in the spring. Estimates of the catches totaled 102,189 lb for the 13 trips, or an average of 7,860 lb per trip (Table 5). Table 5. — Catch (pounds and percentage) and (in parentheses) percentage composition of the catch from 226 trap net lifts in U.S. waters of the western basin, April-November 1969. Category, and Estimated weight of total catch Es of timated weight discarded fish Estimated of landed weight fish Actual of Ian weight dings Pounds % Pounds % total catch Pounds J total catch Pounds : High value Walleye 748 1 226 1 (30) 522 1 (70) 498 1 Medium value Yellow perch 33,665 33 2.514 8 (7) 31,151 44 (93) 31,177 46 White bass 9.759 10 1,318 4 (14) 8,441 12 (86) 9,288 14 Channel catfis >h 3,232 3 936 3 (29) 2,296 3 (71) 2,252 3 Subtotal 46,656 46 4,768 15 (10) 41,888 59 (90) 42,717 63 Low value Freshwater drum 39.408 39 13,712 43 (35) 25,696 36 (65) 21,589 32 Carp 6,447 6 4,870 15 (76) 1,577 2 (24) 1,578 2 Goldfish, carp X goldfish 4,567 4 4,567 14 (100) — — — — -- Bullheads 367 iri' 69 Tr (19) 298 Tr (81) 365 1 White sucker. redhorse 965 1 719 2 (75) 246 Tr (25) 547 1 Buffalo, qulllback 566 1 340 1 (60) 226 Tr (40) 267 Tr Gizzard shad. alewife 2,465 2 2,465 8 (100) — — — — — Subtotal 54,785 54 26,742 84 (49) 28,043 40 (51) 24,346 36 Grand total 102,189 - 31,736 -- (31) 70,453 -- (69) 67,561 - - Tr - <0.5X. Table 6. — Projection of the commercial yield from haul seines and trap nets in U.S. waters of the western basin in 1969. Haul seines Trap ne ts Combined gear Category, and Actual Projected Actual Projected Actual Projected species production production production production production production Pounds % Pounds Pounds X Pounds Pounds Pounds High value Walleye 21,194 Tri' 21,194 158,296 7 158,296 179,490 179,490 Whitefish — — -- 488 Tr 488 488 488 Subtotal 21,194 Tr 21,194 158,784 7 158,784 179,978 179,978 Medium value Yellow perch 73,080 1 73.080 952,453 39 952,453 1,025,533 1,025,533 White bass 465,368 8 465,368 631,326 26 631,326 1,096,694 1,096.694 Channel catfish 459,705 8 459,705 127,981 5 127,981 587,686 587,686 Subtotal 998,153 18 998,153 1,711,760 70 1,711,760 2,709,913 2,709,913 Low value Freshwater drum 1,613,841 29 2,238,397 277,945 11 426,368 1,891,786 2,664,765 Carp 2,800,998 50 3,089,500 164,032 7 670,563 2,965,030 3,760,063 Goldfish, carp X goldfish 98,912 2 531,059 - - 92,232 98,912 623.291 Bullheads 21,466 Tr 27.777 11,904 1 14,666 33,370 42,443 White sucker, redhorse 32,997 1 77,246 78,581 3 308,258 111,578 385,504 Buffalo, qulllback 21,594 Tr 36,278 33,638 1 84,230 55,232 120,508 Gizzard shad, alewife — — 261,941 - - 49.780 - 311,721 Others^' 17 Tr 17 224 Tr 224 241 241 Subtotal 4,589,825 82 6,262,215 566,324 23 1,646,321 5,156,149 7,908,536 Grand total 5,609,172 -- 7,281,562 2,436,868 -- 3,516.865 8,046,040 10.798,427 ■'Tr = cO.SX. ■Others: rainbow smelt, mooneye, burbot, American eel, bowfin. Actual landings averaged 5,197 lb per trip, or about two-thirds of the total catch. This figure compares favorably with my estimate of 5,419 lb landed per trip, or 699'- of the catch. Discarded fish averaged 2,441 lb per trip or Sl'~'r of the catch and consisted of 2,057 lb of low-value fish- es and 384 lb of undersized fish of high or me- dium value. Low-value species accounted for 54% of the estimated total catch (by weight), 36% of the landed catch (as compared with my estimate of 40%), and 84 ""r of the discarded fish. Fresh- water drum were dominant in both the total catch and the discarded portion. Medium-value fish accounted for about 46% of the estimated total catch, 59% of the estimated weight of landed fish, and 15% of the discards. Yellow perch, second in abundance among individual species in the estimated total catch, ranked first in the landed catch. White bass were also sig- nificant in the total and in the landed catch. High-value species (walleye) accounted for only 0.7% of the total catch, and for this same per- centage of landings and discards. The sale value of the catch from a day's lift of trap nets averaged $547, based on jirevailing prices paid at the time the catches were made. At 2^ per pound, the potential worth of the dis- carded catch averaged $41 per day. Athough little interest has been shown among trap net- ters in increasing the landings of species that are worth only 2 or Sf* per pound, conversations with these fishermen indicated that they would willingly land the low-value fishes for 5 to 7'' per pound minimum. Even though sizable quantities of the low-value fishes are usually available, it is unlikely that the trap netters will increase their landings under existing condi- tions. POTENTIAL CATCHES The commercial yield of high- and medium- value s]3ecies could not have been increased in 1969 without an increase in fishing effort, since all fish of legal size were kept. An increase in production could have been realized only by keep- ing the discarded low-value fishes. In estimating the potential harvest of the unused fish in west- ern Lake Erie by haul seines and trap nets in 1969, I assumed that the relation between the landed and discarded fish in the observed catch- es was generally characteristic of the total U.S. fishery for the western basin. Estimates of the landed and the discarded fish from the catches of the 14 seine hauls and 226 trap net lifts were used to determine the poten- tial commercial harvest in the western basin in 1969. A total of about 188,000 pounds of fish were taken in the seine hauls and trap net lifts observed. The projected catch was computed for each species (except gizzard shad and gold- fish— see below) by first determining a numer- ical factor from the ratio of landed fish to the total catch in the hauls and lifts observed. The 1969 commercial production for each species was then multiplied by its corresponding factor to give the projected production for that partic- ular species. For example, since 13,712 of the 39,408 lb of freshwater drum taken by trap nets were discarded (Table 5), the estimated landed catch of 25,696 lb of freshwater drum would have been increased 1.534 times if the discards had been kept. In turn, the U.S. commercial catch of 277,945 lb of freshwater drum by trap nets from the western basin in 1969 was project- ed (X 1.534) to a production of 426,368 lb (Table 6). Computations for two species — gizzard shad and goldfish — differed from that ' described above. Gizzard shad were not kept by haul seiners and neither gizzard shad nor goldfish by trap net fishermen. To compute the catches of these species, I determined the ratios of discard- ed weight of both species to the landed catch of all low-value species in the hauls and lifts ob- served (Tables 4 and 5). The 1969 commercial yield for all low-value species was then mul- tiplied by the percentages of discarded specimens of both species to estimate their potential yield by the designated gear. For example, over 2,640 lb of gizzard shad were caught and released from the observed seine hauls — or about 6% of the 46,259 lb of low-value species that were landed. This percentage, multiplied by the 4,589,825 lb of commercially produced low-value fishes in 1969, provided a potential yield of 261,941 lb of gizzard shad that could have been harvested by haul seines in 1969. This method was also used to determine the potential yield of gizzard shad and goldfish in trap nets in 1969. Incidental catches of the miscellaneous low-value species were not projected because their potential yields would be insignificant (see Table 6). Haul seme catch es The U.S. haul seine production in the western basin in 1969 totaled 5.6 million lb. However, if all low-value fish had been kept, the total would have been 7.3 million lb (Table 6). Most of the increased yield would have consisted of freshwater drum, goldfish, carp, and gizzard shad. A possible discrepancy arises in estimates be- cause it is not known how continuous landings of discarded fish affect the catches in subsequent hauls. Continuous cropping would probably re- duce the population faster than it could be re- placed by movement from unfished areas and by growth and recruitment. However, large quan- tities of these low-value species were sometimes present at the seining grounds a few days after sizable landings had been made. In fact, seine hauling was frequently discontinued because of an overabundance of low-value fish, which forced temporary gluts in an unstable market. In gen- eral, I believe that the poundages of the dis- carded catches from haul seines represented only a small portion of the vast populations of low- value fishes that were lightly exploited. Trap net catches In 1969, trap net yield from the U.S. portion of the western basin totaled 2.4 million lb. The low-value fishes could have contributed another 1.1 million lb if the discards had been kept, to yield a total trap net production of 3.5 million lb (Table 6). Most of the estimated increase in production would have consisted of carp, suck- ers, freshwater drum, and goldfish. Although the projected yield of the low-value fishes by trap nets was 4.6 million lb less than for haul seines, it appears that the potential catch of these spe- cies by trap nets could (with a moderate in- crease in fishing eflFort) equal and possibly ex- ceed that from haul seines without endangering the resource. Combined catches The combined production for haul seines and trap nets in U.S. waters of the western basin in 1969 totaled over 8.0 million lb, and was worth about $990,000 to the fishermen on the basis of the value of the total U.S. commercial catch from Lake Erie in 1969. The nearly 2.8 million lb of discarded low-value fishes, if landed at a price of 2ectf>i gibbus. Bv Don- ald M. Allen and T. J. Costello. May 1972, iii + 19 pp., 9 figs., 1 table. For sale by the Superin- tendent of Documents, U.S. Government Printing Office, Washington, D.C, 20402 - Price 35 cents. UNITED STATES DEPARTMENT OF COAAMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION NATIONAL MARINE FISHERIES SERVICE SCIENTIFIC PUBLICATIONS STAFF ROOM 450 1107 N E 45TH ST SEATTLE, WA 98105 OFFICIAL BUSINESS FOURTH CLASS POSTAGE AND FEES PAID US DEPARTMENT OF COMMERCE COM 210