JOURNAL OF SHELLFISH RESEARCH VOLUME 2, NUMBER 1 JUNE 1982 The Journal of Shellfish Research (formerly Proceedings of the National Shellfisheries Association) is the official publication of the National Shellfisheries Association Editor Dr. Robert E. Hillman Battelle New England Marine Research Laboratory Duxbury, Massachusetts 02332 Managing Editor Dr. Edwin W. Cake, Jr. Gulf Coast Research Laboratory Ocean Springs, Mississippi 39564 Associate Editors Dr. Jay D. Andrews Cornell University Virginia Institute of Marine Sciences Ithaca, New York 14853 Gloucester Point, Virginia 23062 Dr. Richard A. Lutz Dr. Anthony Calabrese Nelson Biological Laboratories National Marine Fisheries Service Rutgers University Milford, Connecticut 06460 Piscataway, New Jersey 08854 Dr. Kenneth K. Chew Dr. Gilbert Pauley College of Fisheries College of Fisheries University of Washington University of Washington Seattle, Washington 98195 Seattle, Washington 98195 Dr. Paul A. Haefner, Jr. Dr. Daniel B. Quayle Rochester Institute of Technology Pacific Biological Laboratory Rochester, New York 14623 Nanaimo, British Columbia, Canada Dr. Herbert Hidu Dr. Aaron Rosenfield Ira C. Darling Center National Marine Fisheries Service University of Maine Oxford, Maryland 21654 Walpole, Maine 04573 Dr. Frederic M. Serchuk Dr. Louis Leibovitz National Marine Fisheries Service New York State College of Veterinary Medicine Woods Hole, Massachusetts 02543 Journal of Shellfish Research Volume 2, Number 1 June 1982 Journal of Shellfish Research, Vol. 2, No. 1, 1, 1982. This issue of the Journal of Shellfish Research is dedicated to the memory of JAMES BENNETT ENGLE AUG 1 2 1983 " JAMES BENNETT ENGLE, Jim or "Uncle Ben, as his reports including 12 in the Proceedings of the National many friends knew him, was born 25 July 1 900 in Newark, Shellfisheries Association, the forerunner of the Journal of NJ. He was educated at Newark College of Engineering, and Shellfish Research. He received many honors during his at Columbia and Rutgers universities. During his 35 years of lifetime including the Meritorius Service Award of the U.S. distinguished service as a shellfish biologist, Jim was employed Department of the Interior. by the U.S. Bureau of Fisheries, the Maryland Department Jim Engle was a long-time member of the National Shell- of Natural Resources, the Virginia Fisheries Laboratory, the fisheries Association (1940-1981). During those 41 years, U.S. Fish and Wildlife Service, the U.S.Bureau of Commercial he seldom missed an annual NSA meeting and served on Fisheries, and the U.S. National Marine Fisheries Service. numerous standing committees. He served as the Associa- He served as a Graduate Assistant with Dr. Thurlow C. tion's Vice-President from 1950 to 1952, and as President Nelson; as Assistant Director of the BCF Laboratory at from 1952 to 1953. Jim was elected to Honorary Member- Milford, CT; as Chiefof Shellfish Research in Yorktown, VA ship in 1970. and A nnapolis, MD; and as Director of the NMFS Laboratory JAMES BENNETTENGLE, shellfish biologist par he at Oxford, MD. He organized and became the first director excellence, was a man of high integrity and dedication; of the National Shellfish Advisory Service which later was loved and respected by his many, many friends and became the Sea Grant Marine Advisory Service. colleagues. His avocation was working with young people, Jim Engle's shellfish interests included oyster predators especially through the Boy Scouts of America. He passed is survived his (drills and seastarsj and associate mussels, seed beds and away 23 October 1981 at Easton, MD. He by and setting, and oyster resources and management. He conducted wife, Isabel, of Oxford, MD, two daughters, Nancy in NSA. We numerous field investigations from Long Island Sound to Susan, and a great many friends and colleagues us. have all his work and among Mississippi Sound including Delaware, Chesapeake, and benefited from presence We all miss him in NSA, but his spirit lives on. Mobile bays. He published at least 60 technical papers and Aaron Rosenfield and Edwin W. Cake, Jr. Journal of Shellfish Research, Vol. 2, No. 1, 3-13, 1982. GROWTH, MORTALITY, AND COPPER-NICKEL ACCUMULATION BY OYSTERS (CRASSOSTREA VIRGINICA) AT THE MORGANTOWN STEAM ELECTRIC STATION ON THE POTOMAC RIVER, MARYLAND GEORGE R. ABBE Academy of Natural Sciences of Philadelphia Benedict Estuarine Research Laboratory Benedict, Maryland 20612 ABSTRACT Growth of three size classes (initially 20-, 40-, and 80-mm shell height) of" the oyster Crassostrea virginica (Gmelin) was observed during a 23-month period beginning in December 1976 at the intake and discharge canal areas of the Potomac Electric Power Company's Morgantown generating station located on the Potomac River in Charles County, Maryland, and at a control area in Shady Side, Anne Arundel County, Maryland. A fourth size class (31 mm initial shell height), added to the study in October 1977, was observed for 13 months. In addition, 10 oysters were analyzed monthly from each area for uptake of copper and nickel. Shell growth of oysters was excellent in all three areas during the 1977 season (salinity >9 ppt), despite average discharge- canal temperatures 6 C above intake temperatures. Poor shell growth occurred in all three areas during the 1978 season, probably because of low salinity (< 6 ppt). Low salinity during 1978 and high discharge-canal temperatures eventually resulted in near total mortality among discharge-canal oysters. Analysis of regression-generated growth curves revealed that growth of controls was significantly greater (p < 0.001) than that of discharge-canal oysters in all four size classes, and growth of intake oysters was significantly greater (p ^ 0.002) than that of discharge canal oysters in three of four classes. However, controls grew more than intake oysters in two of four classes (p < 0.001), but intake oysters outgrew controls = in a third size class (p 0.002). Metal studies indicated no effect of plant operation on nickel accumulation, but uptake of copper was directly associated with operation. Oysters were able to eliminate much of the accumulated copper within 2 months of transfer to the control area. INTRODUCTION power plant on the Potomac River and at the Calvert Cliffs Nuclear Power Plant on Chesapeake Bay, respectively. Thermal effluents from electric generating stations may This a of growth, mortality, and have both beneficial and detrimental effects on oysters. paper presents study a of 13 C metal accumulation by tray-held oysters in the effluent Breeze ( 1971 ) showed that temperature increase (from 12° to 25°C) would increase the growth of hatchery- canal of the Potomac Electric Power Company's (PEPCO) produced seed oysters and thereby ensure survival after Morgantown generating station, a two-unit fossil-fueled planting and possibly shorten the time to harvest. Tinsman plant producing approximately 1,150 megawatts. The 6 and Maurer (1974) and Gilmore et al. (1975) also demon- once-through cooling systems uses 3.8 X 10 E/min (1.0 X 6 strated increased shell growth by oysters raised in heated 10 gpm) of Potomac River water which has a temperature waters, but Tinsman and Maurer (1974) found that the increase of up to 8.3°C as it passes through the 70-30 copper- wintertime advantage of oysters maintained in the effluent nickel condensers (Guiland 1977). Low-level chlorination of the Delmarva power plant in Indian River Bay, Delaware, to prevent biofouling is continuous during warm months was partially lost in summer when the oysters had poorer (when river temperature exceeds 10°C), with each unit meat condition and suffered higher mortalities than controls. receiving about 907 kg/day chlorine. Chlorine residuals A major problem of certain power plant effluents is are typically 0.02 to 0.05 mg/C at the condenser outlets that they contain elevated levels of metals acquired on and decay continues as the water moves along the 630-m transit through the plant. Because many generating stations discharge canal to the river. with once-through cooling systems use 70-30 copper-nickel Studies of growth and survival of oysters in this canal alloy condenser tubes, the uptake of these metals by nearby are not new. Powell (1973) spent several years determining oysters is a concern. O'Connor (1976) stated that the whether the canal could be used to overwinter very young Chalk Point generating station on the Patuxent River in hatchery seed. He stated that oysters could overwinter not be Maryland discharges 1.8 to 7.3 t (2 to 8 tons) of copper there with very high survival, but that they should annually to the river. Roosenburg (1969) found high copper left year-round because the salinity was often too low to concentrations in oysters near the Chalk Point discharge allow normal growth. The salinity of the Potomac near and showed that concentrations decreased as distance from Morgantown ranges from less than 5 ppt to about 12 ppt the plant increased. Abbe and Krueger (1977a) and Abbe (Simmonds and Berseth 1977), but was in the lower part of (1981a) have shown similar results at the Morgantown this range much of the early and mid 1970's(Abbe 1977). ABBE Loosanoff (1953) established that oysters do not grow well creek in Shady Side near the hatchery oysters which had at salinities less than 7.5 ppt, and feeding ceases below 5 ppt been removed from the discharge canal and returned to (Galtsoff 1964). Shady Side for the summer. Except during the winter, oysters were measured approximately once each month. MATERIALS AND METHODS Two replicates of five additional 70- to 90-mm oysters In December 1976, at the request of PEPCO, we began a were also collected monthly from each of the three areas study of the growth and mortality of three size classes of for determination of copper and nickel concentrations. the oyster Crassostrea virginica (Gmelin) in the discharge These oysters were scrubbed, rinsed with distilled water, canal and on the river side of the intake curtain wall of the shucked, rinsed again, and blotted dry.