Proceedings of the Back Bay Ecological Symposium
Back Bay Ecological Symposium
Studies conducted of Back Bay during 1950-51 and 1959-62 showed the fish populations were dominated by freshwater species. Major species included largemouth bass, channel catfish, yellow perch and carp. The average salinities during the study periods were below 0. 7 ppt. Salt water was pumped into the Bay by the City of Virginia Beach from 1965-1973 increasing the average salinity to 2.8 ppt. When pumping was discontinued in 1973, salinity decreased to pre-pumping levels until August, 1978.
The fish population was surveyed in 1978, 1979 and 1980 when it was again found to be dominated by freshwater species, providing an outstanding sport fishery for largemouth bass, black crappie and bluegill. The City resumed saltwater pumping in August, 1978 and continued to August, 1987 maintaining salinities from 1.7 to 5.3 ppt. Surveys conducted during 1985 and 1986 showed the (freshwater) fishery had shifted to predominantly brackish/marine species, which included bay anchovy, white perch, spot and Atlantic menhaden. The results from rotenone and trawl/seine samples showed the fish population comprised of 74 to 97 percent brackish/marine species. After pumping was discontinued the salinity gradually declined to less than 1.0 ppt by 1989. Fish population surveys during 1989 showed an increase in freshwater fishes, mainly in the tributary creeks and canals, where over 60 percent of the fishes were freshwater.
Southwick, Ronald and Norman, Mitchell D., "Impact of Salinity Changes on Fish Populations in Back Bay, Virginia, 1950-1989" (1991). II. Fauna. 6.