The Fishes of the Shore Zone of Rehoboth and Indian River Bays, Delaware

Abstract

Twenty collections from 18 stations in Indian River and Rehoboth bays, June 1968 to April 1970, yielded 41,286 fishes representing 46 species. Five species, ecologically important as food for many local commercial species, comprised 89% of the total catch and were, in order of abundance: Fundulus majalis, Menidia menidia, Fundulus heteroclitus, Pseudopleuronectes americanus, and Anchoa mitchilli. Combined average biomass estimates for the five species were 55 kg/ha and 28 kg/ha for Rehoboth Bay in 1968 and 1969 respectively, and 76 kg/ha and 37 kg/ha for Indian River Bay in 1968 and 1969 respectively. Greatest species diversity and abundance occurred in summer, probably because this is when many of these species collected use these bays as nursery and feeding grounds. F. majalis, M. menidia, F. heteroclitus, P. americanus, Cyprinodon variegatus, and Syngnathus juscus apparently reside in these waters and spawn there during the spring and summer. Juveniles of many commercially important middle Atlantic species were also found in the bays during these seasons. P. americanus were the only fish available in any quantity to commercial and sport fisheries in the study areas. Other commercial fishes typical of the middle Atlantic region, such as Brevoortia tyrannus, Pomatomus saltatrix, and Paralichthys dentatus, were either scarce or occurred sporadically. Changes in species composition and numbers that have occurred in these bays during the past 12 years are probably the result of increased pollution and general environmental degradation.