Effects of predation by sea-run juvenile alewise (Alosa pseudoharengus) on the zooplankton community at Hamilton Reservoir,Rhode Island

The zooplankton of Mill Pond and Hamilton Reservoir in the Annaquatucket River drainage system, North Kingstown, R.I., were compared. While the taxonomic composition of the heleoplankton of the two ponds was similar, the ponds differed in dominant species of Cladocera, distribution of species during the year, and abundance of each taxonomic group. These differences are attributed to the abundance of juvenile Alosa pseudoharengus in Hamilton Reservoir. Overexploitation of food resources is the probable cause of reduced growth of juvenile alewives from Hamilton Reservoir.