Secondary Production of Macrobenthic Invertebrates from Delaware Bay and Coastal Waters

Abstract

Secondary production of benthic invertebrates was estimated for Delaware Bay and coastal Delaware. Production and turnover ratios were highest in Delaware Bay (P = 46,572 mg AFDW m−2 yr−1, P:B = 6,O) and progressively lower at two coastal stations (P = 7,501 to 30,124 mg AFDW m−2 yr−1, P:B = 2.3 to 5.3, and P = 4,485 to 4,492mg AFDW m−2 yr−1, P:B =2.3 to 4.8). Production was inversely related to sediment particle size. Production in Delaware Bay was relatively evenly distributed between deposit feeding polychaetes and suspension feeding molluscs with a definite shift in production dominance to suspension feeding molluscs at the coastal stations. Moreover, crustaceans and echinoderms played a larger role in production at the coastal stations than in Delaware Bay. Concerns about the health of soft-bottom communities in Delaware Bay expressed earlier were not supported here. Finally, it was concluded that P and P: B from the Delaware Bay area were very similar to those obtained from other areas in the North Atlantic which agrees with estimates for other estuaries in the northern hemisphere.