Historical Trends in Abundance of American Shad and River Herring in Albemarle Sound, North Carolina

Abstract

Abstract The Albemarle Sound basin once supported large fisheries for American shad Alosa sapidissima and river herring (alewife Alosa pseudoharengus and blueback herring Alosa aestivalis combined); however, current landings of both stocks are extremely low. We used catch-per-unit-effort (CPUE) data from an 1845–1907 haul-seine fishery to estimate the historical abundance and productivity of these stocks. These historical data are valuable because we can measure (1) the response of the stocks to a period of no fishing during the Civil War and (2) stock productivity before significant changes in water quality and habitat. We found that biomass-based models fitted the historical haul-seine CPUE data reasonably well, but the models appeared to be unreliable for forecasting. For river herring, an analysis that included 1977–1993 pound-net CPUE data appeared to provide better management advice. Estimates of the population growth rate (r) ranged from 0.5 to 0.9 for American shad and 0.3 to 0.5 for river herring...