Dietary habits of selected species of fish resident or transitory to the maryland coastal bays and their importance to understanding food webs

The diet habits of fish taken from Maryland's coastal bays were examined for the purpose of determining prey preferences. Prey resources were recorded for target species by dissecting stomachs of fish collected from April 2007 to October of 2007. Nine sites were sampled once a month during this period using an 18.2 meter bag seine to retrieve fishes. Fish collected from northern and southern sites in the coastal lagoons were compared to see possible changes in stomach content, because there are ecological differences between the northern and southern coastal bays. Seven hundred and fourteen individuals of comprising 23 species were collected. Spot (Leiostomus xanthurus) was the most abundant species (n = 258) with sizes ranging 3.7cm-20cm. With the exception of species from the family cyprinodontidae (striped killifish (Fundulus majalis), mummichog (Fundulus heteroclitus), banded killifish (Fundulus diaphanus) and marsh killifish (Fundulus confluentus) other target species were mostly juveniles. Six of the target species (marsh killifish, banded killifish, mummichog, sheepshead (Archosargus probatocephalus), Black drum (Pogonias cromis) and weakfish (Cynoscion regalis) diets, consisted of two prey species. Four of the target species (spot, silver perch (Bairdiella chrysoura), striped killifish and summer flounder (Paralichthys dentatus)) had a very diverse prey selection with at least 5 different prey items found in their stomachs.

Among all target species benthic macro-invertebrates were the most common prey found in the stomachs. These macro-invertebrates consist of amphipods, copepods, clams, formaniferan, grass shrimp, mysid shrimp, and polychaetes. Amphipods were the most abundant prey. Using Ecopath with Ecosim (version 6), a food web was created using diet information obtained from the literature for most trophic groups. The diet data from this study for some of the target species was used to help create a food web.