Spatial and Habitat-Mediated Food Web Dynamics in An Oyster-Dominated Estuary

ABSTRACT Understanding spatial dynamics and creating spatial boundaries of marine food webs is an important topic that resource managers are beginning to understand. Food web structure, mediated by spatial and habitat differences, was examined in a subtropical estuary using stomach content and stable isotope analyses. The goal of this study was to characterize the trophic structure in subtidal oyster reef, intertidal marsh edge, and nonvegetated bottom habitats. Fish and macroinvertebrates were sampled seasonally from July 2006 to April 2007. Spatially, the lower region of the bay supported a more robust food web, with more species and links (72 and 130, respectively) than the upper bay (63 and 87, respectively). Trophic levels (determined by 15N) and carbon sources (determined by 13C) were combined with dietary links (determined by stomach contents), relative population levels, and linkage strength (determined by food volume) to construct 5 dimensional food web diagrams for the 2 regions and 3 habitats s...