MP 2-74 (Ao-a17 1e) A Glossary of Ecological Terms for Coastal Engineers compiled by Arthur K. Hurme MARCH 1974 MISCELLANEOUS PAPER NO. 2-74 Approved for public release; distribution unlimited U. S. ARMY, CORPS OF ENGINEERS COASTAL ENGINEERING ¢é RESEARCH CENTER 450 Kingman Building ,US Fort Belvoir, Virginia 22060 Wo: Da Reprint or republication ofy any) ot hee iat ee appropriate credit to the U.S. Army Coastal Engineering Research Limited free distribution within the United States of single copies of this publication has been made by this Center. Additional copies are available from: National Technical Information Service ATTN: Operations Division 5285 Port Royal Road Springfield, Virginia 22151 The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) Seu Eat ue READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM 1. REPORT NUMBER 2. GOVT ACCESSION NO.| 3. RECIPIENT'S CATALOG NUMBER MP 2-74 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED A GLOSSARY OF ECOLOGICAL TERMS FOR COASTAL Miscellaneous Paper ENGINEERS 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(s) 8. CONTRACT OR GRANT NUMBER(a2) Arthur K. Hurme 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK AREA & WORK UNIT NUMBERS Department of the Army Coastal Engineering Research Center (CERRE-EC) Kingman Building, Fort Belvoir, Virginia 22060 05-2001 CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE Department of the Army March 1974 Coastal Engineering Research Center 13. NUMBER OF PAGES Kingman Building, Fort Belvoir, Virginia 22060 MONITORING AGENCY NAME & ADDORESS(/f different from Controlling Office) 15. SECURITY CLASS. (of this report) Unclassified 1Sa. DECL ASSIFICATION/ DOWNGRADING SCHEDULE DISTRIBUTION STATEMENT (of thle Report) Approved for public release; distribution unlimited DISTRIBUTION STATEMENT (of the abstract entered in Block 20, If different from Report) SUPPLEMENTARY NOTES KEY WORDS (Continue on reverse side if necessary and identify by block number) Glossary Ecology Coastal Engineering ABSTRACT (Continue on reverse side if necesaary and identify by block number) A glossary of basic ecology terms commonly encountered in the field of coastal engineering. The terms are applicable to, but not necessarily restricted to, marine and freshwater environments of the coastal zone. Terms are cross-referenced and defined in nontechnical language for use by non- ecologists. DD , Renrrs 1473 EpItTion OF 1 NOV 6515S OBSOLETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) PREFACE Recent increased public awareness of man’s role in the environment has resulted in a proliferation in usage of technical ecological terminology. Many of these terms, popularized through common lay usage, have lost their original meaning or the meaning has become obscured. This glossary is designed to provide the coastal engineer with clear, nontechnical definitions of common coastal ecology terms. It is not intended as an authoritative technical reference for the professional ecologist. The definitions are syntheses of numerous definitions; no one source can be credited as a reference. Definitions and usage of many of the terms are still debated among professionals in the field and precise definitions may still be elusive. The reader is referred to the following sources for the precise definition of a specific term used in a limited sense. ALLEE, W.C., et al., Principles of Animal Ecology, Saunders, Philadelphia, 1949, 837 pp. BARNES, R.D., Invertebrate Zoology, 2nd ed., Saunders, Philadelphia, 1968, 743 pp. DAUBENMIRE, R.F., Plant Communities, A Textbook of Plant Synecology, Harper and Row, New York, 1968, 300 pp. GREIG-SMITH, P., Quantitative Plant Ecology, gnd | ed., Butterworth, Washington, D.C., 1964, 242 pp. HEDGPETH, J.W., ed., Treatise on Marine Ecology and Paleoecology, Vol. I., Geological Society of America, New York, 1957, 1296 pp. McCONNAUGHEY, B.H., Introduction to Marine Biology, Mosby, St. Louis, 1970, 449 pp. MOORE, H.B., Marine Ecology, Wiley, New York, 1958, 493 pp. ODUM, E.P., Fundamentals of Ecology, Saunders, Philadelphia, 1971, 574 pp. The glossary was compiled by Arthur K. Hurme, Ecology Branch, under the general. supervision of Mr. R. Yancey, Chief, Ecology Branch, and Mr. R. Savage, Chief, Research Division. NOTE: Comments on this publication are invited. Approved for publication in accordance with Public Law 166, 79th Congress, approved 31 July 1945, as supplemented by Public Law 172, seth Congress, approved 7 November 1963. JAMES L. TRAY Colonel, Corps of Commander and Director A GLOSSARY OF ECOLOGICAL TERMS FOR COASTAL ENGINEERS Bay). ee adaptive radiation — An evolutionary proc- ess whereby a species goes through evolutionary divergence from a single phyletic line (a single species) into a series of different niches or adaptive zones usually as the result of intraspe- cific competition. aerobe—An organism that can live and grow only in the presence of oxygen. aggregation—(1) The clumping or nonran- dom distribution of individuals. (2) A situation where certain dominant species or genera are always found in certain niches and have similar communities or associations. algaculture—The growing, or farming, of algae, usually as a food source for higher organisms. See also aquaculture and mariculture. alkaline—The excess of hydroxyl ions over hydrogen ions. Seawater is usually alkaline. alkalinity—The capacity of a water to accept protons, i.e., hydrogen ions. It is usually expressed as milliequivalents per liter. allochthonous—Usually refers to material resources which originated outside the division of an ecosystem under consid- eration. allogenic succession — Succession induced by geochemical processes acting from outside the local community. amensalism—The interaction of two species resulting in one specics being inhibited and the other not affected. anabolism—The metabolic process of build- ing products from less complex substan- ces (e.g., proteins from amino acids)—as opposed to catabolism. See also metabo- lism. anadromous—A life cycle in which matu- rity is attained in the ocean and the adults ascend rivers and streams to spawn in freshwater (e.g., salmon). anaerobic—An oxygen-independent type of respiration. anaerobic sediment—A highly organic sedi- ment with no’ free oxygen present. Usually rich in hydrogen sulfide. | anaerobic zone—A zone where oxygen is lacking. Substances are reduced, not oxidized. anaerobe—An organism living under no or little oxygen concentrations. See also facultative anaerobe and obligate anaer- obe. annuals—Plants that go through an entire life cycle of seed to adult to seed in one year. antagonism—A relationship between species in which at least one species is harmed. antibiosis—The relationship between spe- cies in which certain substances pro- duced or excreted by one species are generally harmful to others (e.g., fish kills caused by red tide toxins). aphotic zone—An aquatic zone of no light penetration, therefore, no primary pro- ductivity takes place in this zone. A—Continued aquaculture—The farming of fish, shellfish, algae and other aquatic organisms and the development of methods of rearing aquatic organisms. See also algaculture and mariculture. aquatic—Growing or living in, or frequent- ing, water—as opposed to terrestrial. assimilation—The uptake of food material for production of new biomass. association—In an ecological sense, a subunit of community organization identified by its major organisms. aufwuchs—See periphyton. autecology—The study of the individual organism or species rather than the community. Life history and behavior, rather than adaptation to environment, are usually emphasized. autogenic succession — Succession induced by biotic processes acting from within the system. autolysis—Self-breakdown of a cell. This is one pathway in detrital recycling of nutrients. autotomy—The process of self-amputation of extremities or organs by reflex action. Regeneration usually follows. autotroph—A self-nourishing organism that makes its own food from inorganic components. autotrophic—(1) The process by which an organism manufactures its own food from inorganic compounds. (2) The ability to use simple inorganic substances and an energy source for synthesis of more complex compounds (e.g., green plants). Compare with hetrotrophic. autotrophic succession — A type of com- munity succession in which productivity exceeds respiration in early successional stages, but the two tend to equilibrate in “more mature stages. Compare with heterotrophic succession. Resi 29 ele balanus zone — The area where balanoid (stalkless, sessile) barnacles inhabit the shore, generally restricted to part of certain intertidal and splash zones. barriers — In an ecological sense, those physical, chemical, climatic or biologic factors which are foreign to an orga- nism’s native habitat and exceed the tolerance of that organism. These factors may offer enough resistance to stop the dispersal or force the retreat ‘of that organism. benthic — Pertaining to the bottom. subaquatic benthos—A collective term describing: (1) Bottom organisms attached or resting on or in the bottom sediments. (2) Com- munity of animals living in or on the ‘bottom. bioassey—The use of living organisms as an index to determine environmental con- ditions. Biochemical Oxygen Demand (BOD)—The amount of oxygen required by the biological population of a water sample to oxidize the organic matter in that water. It is usually determined over a 5-day period under standardized labora- tory conditions and hence may not represent actual field conditions. B—Continued biocoenosis — Approximately equal to a biotic community of plants (phyto- coenosis) and animals (zoocoenosis). See also biogenocoenosis and ecosystem. bioecology—A collective term that includes plant and animal ecology as one discipline. bioenergetic—Of or relating to the energy flow of a population of organisms. biogenic deposits— A geological deposit resulting from the physiological activity of organisms such as calcareous algae. biogeochemical cycling — The cycling of chemical constituents through a biolog- ical system. biogeocoenosis—Any unit that includes all the organisms, i.e., the biotic community in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity and material cycles within the system. See also biocoenosis and ecosystem. biogeography—The study of geographical distribution of plants and animals and the reasons for the distribution. biological clock — A physiological mecha- nism which allows an organism to estimate time. See circadian rhythm. biological magnification — The concentra- tion of certain substances up a food chain. A very important mechanism in concentrating pesticides and heavy metals in organisms such as fish. bioluminescene—The production of light, without sensible heat, by living orga- nisms as a result of a chemical reaction either within certain cells or organisms or extra-cellularly by some form of secretion. biomass—The amount of living material in a unit area for a unit time. Also standing crop, standing stock, live-weight. biomass pyramids—A graphic representa- tion of biomass at each trophic level. It does not indicate importance of specific organisms. biome—A major community of plants and animals associated with a stable environ- mental life zone or region (e.g., Northern Coniferous Forest or Great Plains). biophages—Those organisms which obtain nourishment from other organisms (e.g., predators, parasites, and pathogens). biosphere—The transitional zone between, and including parts of the earth and the atmosphere where all living organisms commonly dwell. biostrome—Bedded structures such as shell beds consisting of, or built mainly by sedentary organisms. biota—The living part of a system (flora and fauna). biotic community—(1) All of the plant and animal populations occupying a given area, usually named after the dominant (in size or numbers) plant or animal in area. (2) An integrated, mutually adjusted assemblage of organisms inhab- iting a natural area. The assemblage may or may not be self-sufficient and is considered to be in a state of dynamic equilibrium. B—Continued biotic factors — Factors of a_ biological nature such as availability of food, competition between species, preditor- prey relationship etc., which besides the purely physical and chemical factors, also affect the distribution and abun- dance of species. biotic potential—(1) The maximum repro- duction power or ability. The inherent property of an organism to reproduce and survive in greater numbers. (2) The ability of an organism to reproduce in an optimum, unrestricted, noncompetitive environment. biotic succession—The natural replacement of one or more groups of organisms occupying a specific habitat by new groups. The preceding groups in some ways prepare or favorably modify the habitat for succeeding groups. biotope—Habitat, a rather specific kind of living space. See also ecotope. biotype—In plants or animals, a phenom- enon where the genotypes are similar, but the phenotypes are different due to local conditions. birthrate—Number of births in a given time period. Usually expressed as births per 1,000 population per year or per generation. bloom—See plankton bloom. B.O.D.—See Biochemical Oxygen Demand. brine—Water containing a concentration of dissolved salts higher than that of ordinary seawater. budding—An asexual means of reproduc- tion in lower organisms where a small replica of the adult grows from the parent. Stn pam carnivore—A flesh eater. The highest tropic level(s) at the top of most food chains. carrying capacity—The maximum number of a species that any particular area can support over an extended period of time. casts—Deposits of fecal material with attendant undigested sediment. Fre- quently found as pellets or strands. catabolism—The metabolic process break- ing compounds (e.g., sugar) into simpler substances to release energy—as opposed to anabolism. See also metabolism. catadromous—A life cycle in which matu- rity is reached in freshwater and spawning takes place at sea (e.g., the American eel). chemotrophic nutrition — A process by which an organism manufactures its food by using the energy derived by oxidizing inorganic matter. chitin—A nitrogenous polysaccharide form- ing the basic part of the arthropod exoskeleton. chlorophyll—The green pigment used in photosynthesis, found primarily in plants. circadian rhythm—The most common man- ifestation of the biological clock, being the ability to repeat certain functions daily without external clues, such as light-dark cycles. See also diel perio- dicity. C—Continued climatic community—A community that is in equilibrium with the general climate, theoretically the climax or final sere. climax—The final stage in community succession. See also climatic community. clone—A term describing all succeeding generations developed from one parent organism and therefore genetically uni- form. colonization — A natural phenomenon where a species invades an area previ- ously unoccupied by that species and becomes established. To be successful the species must be able to reproduce in that area. commensalism — A relationship between two interacting species or populations in which one benefits while the other remains unaffected. community, biotic—See biotic community. constancy — The percentage of uniform samples containing the species. Used in determining associations. contagious distribution — Nonrandom or clustered distribution of members of same species. coprophagic—Animals that eat feces. crepusular—Refers to twilight time. crude density—See density. cryptozoa—Animals that remain hidden. ay) es decomposers—Usually microconsumer orga- nisms which break down organic matter and thus aid in recycling nutrients. decreasers — A species that decreases in density under continued grazing and hence can be used as an index for range management. Opposite of increasers. demersal—Organisms (usually fish) that live on or slightly above the bottom. density—In an ecological sense density is usually subdivided into two catagories: (1) crude density—the number or bio- mass per unit of total area and (2) specific density—the number or biomass per unit of habitable (colonizable) area. detritovores—Detritus feeders. detritus—Any fine particulate debris, usu- ally of organic origin, but sometimes defined as organic and inorganic debris. diel periodicity — Used in referring to a phenomenon that occurs regularly every 24-hour period. See also circadian rhythm. dimictic lake—A lake with two seasonal overturns (periods of free circulation) usually in spring and fall. dimorphism—Occurrence of two different forms of the same species. dioecious—Male and female reproductive parts in different individuals. disclimax—A stable nonclimax community that is maintained by animals or fire. D—Continued dispersal—Movement of individuals or their disseminants or propagules (seed, spores, larvae) out of a population or area. disphotic zone—The dimly lit zone in bodies of water where there is insuffi- cient light for photosynthesis. diversity—Refers to the number of differ- ent kinds of species in an area. diversity indices—Various formulas convert numbers and importance of species, and numbers of individuals into dimension- less values which indicate variety. dominants—A species or group of species which largely control the energy flow and strongly affect the environment within a community or association. dystrophic lake—A lake which is low in productivity and contains brown-stained, low pH waters which have a high organic content. are ecdysis—The shedding of the old exoskele- ton in arthropods. ecological energetics—The cycling of energy through trophic levels. Some energy is lost when transferred from one trophic level to the next higher. ecological indicators—Species or associa- tions which indicate certain ecological conditions such as soil, type, climate, temperature or salinity. ecological succession—See succession. ecological valency—Refers to the range of environmental variation tolerated by a species. ecosystem—The living organisms and the nonliving environment interacting in a given area. See also biocoenosis and biogeocoenosis. ecotone—A transitional area between two or more communities. See also edge effect. ecotope—Physical environment of a habi- tat. See also biotope. edaphic—A term referring to the soil conditions or types as ecological factors. edge effect — The change increase (usually increase) in species diversity and density in the transitional area between com- munities. See also ecotone. eltonian pyramids—Refers to the concept of representing trophic levels as layers based on numbers of individuals or mass, thus forming a pyramid. Primary pro- ducers create the greatest mass and carnivores the least. See also pyramids. emergent vegetation — Plants which al- though rooted in shallow water have most of their growth above the water. endemic—Native to a specific geographic area. endogenous—Originating or growing from a specific geographic area. energetics, ecological—See ecological ener- getics. epilimnion—In lakes, the layer of water above the thermocline. It is the area where main primary productivity takes place. E—Continued epipelagic — The upper portion of the oceanic province extending from the surface to a depth of about 185 meters. estuary —In ecological usage: a semi- enclosed coastal body of water which has a free connection with the open sea. The seawater is usually measurably diluted with freshwater. eulittoral—That part of the littoral zone less than 50 meters in depth. euphotic zone—The layer of water which receives ample sunlight for photosyn- thesis. It varies with the light extinction coefficient. Usually no deeper thaa about 60 meters. eury—A prefix referring to a wide range of some parameter. Opposite of steno. eutrophic lake — A shallow lake that has good primary productivity, usually abun- dant littoral vegetation, and dense plankton population. Blooms occur when nutrient and physical conditions are right. The bottom water, during later stages of eutrophication, tends to be- come depleted of oxygen during the summer. eutrophication—The process whereby a body of water becomes highly produc- tive due to the input of large quantities of nutrients. It may have high dissolved oxygen concentrations near the surface during the day and low concentrations during the night. The bottom waters usually have low dissolved oxygen and high organic concentrations at all times of day. exoskeleton—A hard outer covering which acts as a support structure for muscle attachment. exotics—Nonendemics. Organisms which are not native but introduced. exploitation—Usually the use of one species by another. Usually only one species benefits from this relationship. 3a iy ees facultative anaerobe — An organism that doesn’t necessarily require lack of oxygen for survival, but is able to live either in the presence (usually at low concentrations) or absence of oxygen. See also anaerobe and obligate anaerobe. fauna—Animal life as opposed to flora (plant life). Generally the entire group of animals found in an area. fecundity—The amount of egg or sperm production per individual or population. feral—An adjective describing formerly domesticated animals gone wild. fidelity—The degree of restriction of a species to a particular association. filter feeding—A feeding process employed by many aquatic organisms in which water currents are passed through a filtering system and small organisms are selectively strained out and eaten. flora—Plant life as opposed to fauna (animal life). The entire group of plants found in an area. F—Continued flushing time—The time required to replace , all the water in an estuary, harbor, etc., by action of current. food chain—The sequence of organisms in which each is food for a higher member of the sequence. Due to energy loss at each level there are usually not more than four or five steps per chain. food cycle—Production, consumption and decomposition of food and the energy relationships involved. food web—A group of interrelated food chains. See also food chain. fouling organism —An_ organism that attaches to the surface of submerged or introduced objects regardless of whether the objects are natural or man-made. Sahih (ean. genotype—The genetic makeup of an orga- nism regardless of whether the genetic trait is expressed or not. geobiocoenois—See biogeocoenois. grazing—In aquatic habitats, the consump- tion of phytoplankton by zooplankton. growth forms—Populations have character- istic patterns of increase which are called population growth forms. These are rep- resented by two curves: (1) J-shaped and (2) S-shaped. Trees, shrubs and herbs also have characteristic growth forms, patterns, or shapes. eye ye (gee a habitat—The place where an organism lives. halophyte—A plant that tolerates and lives in salty soil. herbivores—Animals that feed primarily on plants. heterotrophic—A metabolic process depen- dent on complex organic food origi- nating in other plants and animals. Compare with autotrophic. ‘heterotrophic succession—A type of com- munity succession in which respiration exceeds production in early successional stages, but the two tend to equilibrate in more mature stages. Compare with autotrophic succession. holocoen—The interactions between envi- ronmental factors and organisms, equiva- lent to ecosystem holological approach—Analysis of a system (e.g., as to heat budget) where the system is taken as a whole and treated as a “black box” where only input and output are considered. See also merolog- ‘ical approach. holomictic lakes—Lakes where bottom and surface waters are mixed periodically. home range—The area which an individual or family uses. It is more or less fixed. If actually defended, it is the animal’s territory. homeostasis—The tendency of a system to remain at or return to normal, after or during an outside stress. H—Continued homoiosmotic—Referring to an organism hypertonic—Osmotic concentration higher which steadily maintains a total internal than the surrounding medium. concentration of body fluids independ- eal OF ulbett Gr he enuimoamant hypotonic—Osmotic concentration lower hydrophyte—A water- or moisture-loving than the surrounding medium. plant. As opposed to xerophyte. hypolimnion—That part of a lake below the hydroseres,—A wet sere. See also sere. thermocline. sabes) (arp increasers—A species which increases in instar—A term referring to the period in an abundance under continuous grazing. arthropod’s life between each ecdysis or molt. ‘Opposite of decreasers. intrinsic factors—When referring to coloni- interstitial—A term referring to the spaces zation by an organism, those attributes between particles, (e.g., the spaces or genotypes of that organism which between the sand grains). See also permit it to invade and survive in a new PCiOtaniia area (e.g., locomotor ability, structure, physiological and behavioral properties). eee eee lake, dimictic—See dimictic lake. lentic—Standing waters, lakes and ponds, as opposed to lotic, running waters. lake, dystrophic—See dystrophic lake. light compensation level - The depth at lake, eutrophic—See eutrophic lake. which production by photosynthesis just balances respiration. lake, meromictic—See meromictic lake. hght- dark-bottle technigue—A method for lake, monomictic—See monomictic lake. measuring primary productivity. Two representative water samples are taken lake, oligomictic—See oligomictic lake. and one is covered so no light can penetrate. The bottles are ‘“incubated”’ at the original depths and location, then oxygen content is measured. The differ- ence can be related to productivity. lake, oligotrophic—See oligotrophic lake. lake, polymictic—See polyinictic lake. larva—A sexually immature form of any animal unlike its adult form and requir- hmnetic zone — In freshwater, the water ing changes before reaching the basic zone from the surface to the light adult form. compensation level. 10 L—Continued limnology—The study of freshwater bodies, physically, biologically, and chemically. littoral—Several usages in ecology: (1) The zone between extreme high and extreme low tides. (2) Occasionally the zone from the shore to the light compensation level. (3) In lakes, shallow water from the shore to the light compensation level. (4) The zone from high tide level to edge of Continental Shelf. live weight—See biomass. lotic—Running waters, streams, and rivers as opposed to lentic, standing waters. peasy igepaes macrobiota—Large life forms visible to the naked eye. macroclimate—The most general overall climate picture for an area, usually not specifically including the area immedi- ately next to the surface. See also microclimate. macrofauna—Those animals equal to or larger than 1 millimeter in size. macronutrients—Elements and their com- pounds needed in relatively large amounts as opposed to micronutrients. macroplankton—Planktonic organisms that can be readily seen with the unaided eye or those greater than or equal to 1 millimeter in length. mariculture—The culturing of fish, shell- fish, etc. in saltwater. See also algacul- . ture and aquaculture. marine-littoral sediments—(1) Neritic: Composed of earth mixed with organic substances of shallow water. (2) Terri- genous: Mineralized substances carried into the sea by rivers. marsh—In biological usage: (1) A herbaceous plant-dominated ecosystem in which the rooting medium is inundated for long periods if not continually, (2) An area of 11 soft, wet flatland periodically flooded by saltwater is called a salt marsh. megaloplankton—Plankton greater than 1 centimeter. meiofauna—Generally those interstitial animals between 1.0 and 0.5 millimeters in size. merological approach—As opposed to the “black box” approach, a method which attempts to investigate an ecosystem as individual units making up the whole system. See also holological appraoch. meromictic lake—A permanently stratified lake, most commonly as a result of chemical differences in hypolimnial and epilimnial waters. meroplankton—Nonpermanent planktonic larval stages of benthos and nekton. meso — A prefix referring to or of the middle. mesophyte—Plants adapted to medium moisture conditions, neither a xerophyte nor a hydrophyte. mesoplankton—A subdivision of the macro- plankton containing organisms between 1 millimeter and 1 centimeter in size. It is also used to describe plankton in mid-depth waters and hence can be a confusing term. M—Continued ’ metabolism—The process by which an orga- nism builds and breaks down compounds within the organism. See also anabolism and catabolism. metagenesis — Alternation of generations; the occurrence of an asexual stage fol- lowed by a sexual stage in the life history of an organism. metamorphosis—The process of changing through stages from egg to adult. (1) Complete: egg, larva, pupa, adult. (2) Incomplete: egg, nymph, adult. microbiota—Small microscopic organisms. Opposite of macrobiota. microclimate—The climate conditions in small areas that, due to localized con- ditions, are different from the general climatic conditions in the area (e.g., south-facing slope or under-rock habi- tat). See also macroclimate. microfauna—Those animals equal to or less than 0.5 millimeter in size. micronutrient—A nutrient needed in small or trace amounts, as opposed to macro- nutrient. microplankton—Plankton within size range of 60 micrometers to | millimeter. mixed layer—A water layer mixed by wind, wave, or thermal action. molt—In anthropods, the shedding of the exoskeleton to allow for growth and development. monocultural system—A system where one species is maintained, usually artifically. monoecious—The production of sperm and eggs by the same organism but not necessarily self-fertilizing. monomictic lake—A lake with only one overturn per year. There are two types: (1) Warm—water never below 4°C, over- turn in the winter; and (2) Cold—water never above 4°C, overturn in the sum- mer. mortality—Number of deaths in a given time period. Usually expressed as deaths per 1,000 population per year or per generation. mutualism—A symbiotic relationship in which both members benefit. Neither can survive without the other. res Ne nannoplankton—Plankton in the size range 5 to 60 micrometers, defined as uncatch- able in standard plankton nets. natality—See birthrate. natural selection—The differential perpet- uation of genotypes, where selective pressure favors one genotype over another. 12 nekton—Those aquatic animals able to swim efficiently, and not mainly at the mercy of currents. neritic—(1) Refers to waters over the Con- tinental Shelf. (2) Pertaining to that part Shelf between the low tide line and depths of 200 meters of the Continental including both bottom and_ overlying waters. N—Continued neuston—Those organisms living in associa- tion with the surface film layer at the air surface interface. neutralism—A symbiotic relationship with no effect on either organism. niche—An organism’s habitat and func- tional role in the community. nitrogen cycle—The numerous biogeochem- ical processes which result in the cycling of nitrogen in the many chemical forms required by various organisms. nitrogen fixation—An energy requiring pro- cess whereby nitrogen gas is converted to amino or ammonia nitrogen. Sot) ste ook obligate anaerobe — An organism that re- quires the absence of molecular oxygen to survive. See also anaerobe and faculta- tive anaerobe. oligo—Prefix referring to or of few. oligomictic lake—A lake whose waters are rarely or very slowly mixed. It is ther- mally stable and usually located in the tropics. oligotrophic lake—A lake which is low in nutrients and therefore has low produc- tivity. These lakes are generally geologi- cally young. omnivore—An animal that eats both animal and plant material. organism—Any living individual whether plant or animal. osmoregulation—The ability to regulate ionic concentrations in body fluids. osmosis—The diffusion of substances, solute or solvent, through a semiperme- able membrance from a region of high concentration to a region of low concen- tration resulting in the tendancy for the concentrations to equilibrate. overturn—The mixing of hypolimnion and epilimnion zones in lakes. 13 ovigerous—Bearing eggs as in a _ berried -lobster or crab. oviparous—A form of reproduction where the eggs hatch outside the body. Com- pare with ovoviviparous and viviparous. ovoviviparous—A form of reproduction where the eggs are hatched in the mother’s body, but derive no nourish- ment directly from her. The young are born alive. Compare with oviparous and viviparous. oxygen debt — A temporary phenomenon that occurs in an organism when avail- able oxygen is inadequate for respiratory demand. Partially metabolized products are stored and oxidized when oxygen is available. oxygen deficit — The difference between oxygen, concentration actually present and the amount that would theoretically be present at 100 percent saturation for the existing conditions of temperature and pressure. oxygen sag— The temporary decrease in oxygen concentration due to reduced photosynthesis or increased oxygen demand. Hepp y pandemic—Widespread throughout an area. panne—A depression among dunes kept moist by capillary transport from the water table. parasitism—A symbiotic relationship be- tween two organisms in which one lives in or on the body of its host and obtains nutrition from the host tissue. This is usually harmful or fatal to the host. parthenogenesis—The process by which an egg undergoes development without fer- tilization by sperm. peat—Fibrous, partly decayed fragments of vascular plants which retain enough structure so that the peat can be identi- fied as originating from certain plants (e.g., sphagnum peat or sedge peat). pelagic—All ocean waters covering the ben- thic region. periphyton—Any organism attached or clinging to stems, leaves or other surfaces of plants under the water. See also aufwuchs. phagotrophs—Macroconsumers, _heterotro- phic organisms chiefly animals which ingest other organisms, or particulate organic matter. phenotype—The outward expression of the genotype, usually environmentally influ- enced. philopatry—The tendancy to return to the birthplace. photoperiod — Refers to the number of hours of light or darkness in the day. 14 photosynthesis—The manufacture of carbo- hydrates from carbon dioxide and water in the presence of chlorophyll using sunlight as an energy source. phototrophism—A reaction or response to light. phytocoenosis—The plant community. phytoplankton—Plant plankton. Members of this group are in the ocean and are important primary producers. pisciculture—The growing, or farming of fish. plankter—A planktonic organism. plankton—Those organisms passively drift- ing or weakly swimming in marine or freshwater. plankton bloom—A sudden rapid increase (usually geometric) to an enormous number of individual plankters under certain conditions. See also bloom. poly—A prefix referring to or of many. polymictic lake—A lake which is continu- ally mixing or with very short stagnation periods. polymorphism—The presence of two or more forms (morphs) of the same species (e.g., males and females which differ in appearance). population growth forms—See growth forms. potential, biotic—See biotic potential. P—Continued predation — A relationship between two. _ profundal zone—In lakes, the bottom and species or populations where one direc- deepwater areas beneath the light com- tly attacks (hunts, grasps, kills and eats) pensation level. the other. protista — Acellular organisms having a predator—Animals that actively hunt other nucleus, chromosomes and mitotic cell living animals as a food source. division (e.g., protozoans, most algae, | slime molds and fungi). primary productivity—The rate at which energy is stored by photosynthesizing psammolittoral habitat—Refers to the area organisms (chiefly green plants) in the among the sand grains at the water’s form of organic substances. edge. primary succession — Succession which psammon-—Interstitial organisms found be- starts from a virgin area. Compare with tween sand grains. secondary succession. pyramids—The use of pyramids to show an productivity—The rate at which energy is organism’s tropic level. There are three stored by anabolic processes in orga- basic types: numbers, biomass, and nisms. See also primary productivity. energy. See also eltonian pyramids. eee ReLere red tide—Discoloration of surface waters, respiration—The chemical and _ physical most frequently in coastal zones, caused processes involved in providing oxygen by large concentrations of micro- organisms, particularly dinoflagellates. They may or may not be toxic. for metabolism and removing the carbon dioxide resulting from metabolism. redd—A bed prepared in sand or gravel to rheotaxis—The alignment of an organism in received the spawn of fishes. relation to a current. S69 == salt marsh—See marsh. roundings, usually after the food has been dissolved externally. saprophytic nutrition—The process by which certain plants absorb food from scavengers—Those animals that eat dead their surroundings, usually after the food iia ah has been dissolved externally. sea grass—Members of marine seed plants that grow chiefly on sand or sand-mud saprotroph—An organism that feeds on bottom. They are most abundant in dead organic matter. water less than 9 meters deep. The common types are: Eel grass (Zostera), saprozoic—The process by which certain Turtle grass (Thallasia), and Manatee animals absorh food from their sur- grass (Syringodium). 15 S—Continued seaweed zonation—Zones of algal growth related to mean tide level. Usually desig- nated by type of algae: (1), green seay weed growing in pools near or slightly above high water mark (Enteromorpha); (2), brown, mostly intertidal (Fucus); (3), red, shallow waters offshore or at’ the bottom of deep rock pools. secondary succession — Succession which starts in an area where the previous community was destroyed (e.g., by fire, flood, etc.). sediments, marine-littoral — See marine- littoral sediments. sere—A stage in succession to the climax community. serology—The study of the development of a climax community and the stages that lead to it. sessile—An organism which usually is fixed but may move infrequently or may be permanently attached. seston—Refers to all material, organic and inorganic, suspended in the water column. See also tripton. shellfish—Any aquatic invertebrate with a hard external covering; more commonly mollusks and crustaceans. spat—The larvae of young bivalve mollusks just after settling. spawn—To produce or deposit eggs or sperm (verb). Also the young produced (noun). species—An aggregate of interbreeding pop- ulations that under natural conditions is reproductively isolated. species diversity index—The ratio between the number of species in an area and the 16 importance values (e.g., numbers, bio- mass, productivity) for each species. There are several formulas for species _ diversity indices varying primarily in the determination of the importance values. Each index has its own advantages and limitations. See also Diversity. specific density—See density. splash zone — The zone immediately land- ward of the mean higher high water level affected by the wave spray. See also supralittoral. spring maximum—Occurrence of abundant phytoplankton (predominately diatoms) after a winter minimum. The production of phytoplankton is generally the highest for the year during this period. standing crop—See biomass. standing stock—See biomass. steno—A prefix referring to a narrow range. Opposite of Eury. subclimax—Usually refers to a stage or sere before the climax. sublittoral zone—(1) In lakes, the region below the area of rooted vascular plants extending to the profundal zone (deep bottom). (2) In the oceans, the region extending below the intertidal to the edge of the Continental Shelf. submergent vegetation—Plants which grow primarily under the water surface. succession—In an ecological sense, an orderly process of community develop- ment and changes with time, which results from interactions between species and environment. See also ecological succession. S—Continued succession, allogenic—See allogenic succes- sion. succession, autogenic—See autogenic suc- cession. succession, autotrophic — See autotrophic succession. succession, heterotrophic—See heterotro- phic succession. succession, primary—See primary succes- sion. succession, secondary—See secondary suc- cession. supralittoral—The zone immediately adjacent (landward) to the mean high water level; commonly called the splash zone. See also supratidal. supratidal—See supralittoral. symbiosis—A term referring to two species living together. It may be a commensal, mutual or parasitic relationship. synecology—The study of the ecology of communities, associations or groups of organisms living together, as opposed to autecology. synergism—Total effect of all interactants when acting together is greater than the sum of interactants acting individually. LIVREL phiusie Ls temperature compensation—An organism’s compensatory reaction to changes in temperature via physical change(s) or change(s) in habit(s) which tend to favor maintainence of a more nearly optimal body temperature. terrestrial—Of or relating to the earth and its inhabitants—as opposed to aquatic. territory—The area an animal lives in and actively defends. thallophyte—A taxonomic grouping of sim- ple plants which lack true stems, leaves and roots (e.g., algae, fungi, etc.). thermocline—In vertically stratifical water, the layer where there is a rapid change in temperature from the overlying to the underlying waters. thigmotaxis—The response and alignment to touch or contact. 17 tidal flat—Flat land areas which are covered and uncovered by the rise and fall of the tide. Vegetation, if present, consists of rushes, grasses and other halophytes. tolerance—The relative capability of an organism to endure or adapt to unfavor- able environmental factors. tripton—Dead particulate matter suspended ‘in water; the nonliving part of the seston. trophic levels—Levels of food production and consumption beginning with the primary level, the producers, and con- tinuing up through the consumer levels, the herbivores, omnivores and _ car- nivores. trophism — A directed movement in re- sponse to a stimulus. T—Continued turbidity—A condition where transparency of water is reduced. It is an optical phenomenon and does not necessarily have a direct linear relationship to partic- ulate concentration. turnover—(1) in production, the rate at which something is. used up and re- placed. (2) In a limnological sense, the mixing of layers of lentic waters and the redistribution of oxygen and nutrients. aA Te ultraplankton—Organisms smaller than 5 micrometers in size. Bee es vagility—The innate ability of an organism to move. Locomotion, dispersion, etc. vitality— Reproductive success. viviporous—A type of reproduction where the offspring are born alive. They develop within the mother’s body and derive nourishment directly from her. Compare with oviparous arid ovovivi- parous. SPL Si xeric—A prefix meaning dry. xerophyte—A plant with very low water requirements as opposed to hydrophyte. en 7 YS zoocoenosis—The animal community as opposed to phytocoenosis, the plant community. See also biocoenosis. zooneuston—Animals found on the surface film of water. zooplankton—Animals in the plankton. ici A 3 ase ny} fl Me BN i reaht f=}, ie in tid sroltonshvasth ik WU Meradatte aed | : bis ti WOE ee Tet tags Vetsbya. ned MN, Mr ha Mia i / . . wy ' ‘| , «v4 : Lento af 4S) Sapte | SAAR deat inte ale oe He ewinl LOR a) ihe be hf wn j i PPR) tf’ (yer re Wubi ite Te, it hid - ares id ve a he, uli i un vel rs nels ni ur Pea tabs Nii ty lbh ew : P ; wil . : al ae 7 kisidgy ais Cie ii arte a ees ee enc. ie a M vl ih | ie pos Tia al di * f Bie tpniy Runny 4 UO AR CeCe Map es | At pee a aw vite PUD it Fie ery posi a Aor y i ‘ a\ee | Wate MP Aiea Te ened. A aceninghiye SOE eth aed eye hives Yh Oe) ite qi bot! stad allt heb ogy: yest sire