Abundances and Production of Copepods in the Rhode River Subestuary of Chesapeake Bay

Seasonal fluctuations in zooplankton abundance between July 1973 and July 1974 showed a clear peak in total copepods and rotifers in February-March, and a less pronounced peak in July-August. Standing crop and production estimates for the two dominant copepods, Acarfia fonsa and Eurytemoru uffinis, revealed that the February-March peak was primarily E. affinis and sustained far higher biomass (218.6 mg/m3 ) and production (20.5 mg/m3. day) than did the August peak of A. tonsa (biomass 16.3 mg/m3, production 7.5 mg/m3. day). The Rhode River has low standing crop and production of copepods relative to the much larger Patuxent estuary. These results are consistent with the theory of Williams et al. (1968) that shallow embayments have lower standing crops; however, the statistical basis for their statement is shown to be spurious.