Evaluating and Improving Larval Stocking as a Method to Restore American Shad in Chesapeake Bay
After many years of decline, American shad have been staging a comeback in the Chesapeake. While fishing moratoria in Maryland and Virginia have had some effect, the construction of fish passages at dams so that adult shad can return to freshwater spawning grounds and the state's annual stocking of hatchery-reared larvae into Bay rivers have also been of importance. While larvae are subject to predation, they are subject also to environmental stress, which can result in high mortalities – if those stresses could be minimized by stocking under more optimal conditions, there is the potential to significantly improve their survival. Edward Houde has been working with the Maryland Department of Natural Resources to determine if this is possible – he has been evaluating the environmental impact on shad released at different stages (e.g., 3 and 15 days after hatching). Larvae spawned in the state hatchery during 2000 and 2001 were chemically "marked," then released at different salinity conditions in the Patuxent River. Houde is now analyzing data to determine differences between releasing shad larvae at different development stages and whether there are optimal conditions of temperature and salinity that can improve survival to the juvenile stage.
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Edward D. Houde
Chesapeake Biological Laboratory
University of Maryland Center for Environmental Science
Steven P. Minkkinen
Mariculture, Estuarine and Marine Hatcheries
Maryland Department of Natural Resources
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