| Summary |
Spatial and temporal feeding habits of juvenile white perch (Morone americana) and yellow perch (Perca flavescens) and spatial variability in nitrogen isotopic signatures ([delta]¹⁵N) of white perch muscle tissue was examined in the Albemarle Estuarine System (AES) from June through October 2005. The diets of juvenile white and yellow perch were made up entirely of aquatic invertebrates with copepods typically being the most numerous prey of juvenile white perch. Mysid shrimp and amphipods were the primary source of white perch dietary weight, particularly in late summer and early fall. White perch exhibited a marked change in prey with increased size throughout the AES, switching from smaller pelagic prey (copepods and cladocerans) to larger epibenthic prey (mysid shrimp and amphipods). Amphipods were the primary source of juvenile yellow perch diet weight, which differs from published data on the diet of juvenile yellow perch in freshwater systems. There was a biologically significant degree of dietary overlap between larger-sized juvenile white perch and juvenile yellow perch, which may indicate possible competitive interactions between white and yellow perch in the AES as white perch alter their diet with increased size. There was significant variability in [delta]¹⁵N of white perch muscle tissue, which was not explained by fish size. [delta]¹⁵N was significantly lower in areas surrounded by land that is less subjected to anthropogenic practices (e.g. agriculture, animal farming and urbanization). [delta]¹⁵N was highest at the mouths of the Chowan and Roanoke rivers where values were significantly higher than from within Chowan River proper. There were also significant differences in nitrogen enrichment among juvenile white perch collected over relatively small spatial scales within the Alligator River Estuary. This underscores the importance of establishing discreet isotopic baselines when utilizing stable isotopes to assess trophic relationships within or among systems. This study highlights the significance of benthic communities as a prey source to both juvenile white and yellow perch, as well as lending evidence to the feasibility of utilizing commercially valuable fish species to identify areas of possible concern related to nutrient loading within a system. |
| General note | Presented to the faculty of the Department of Biology. |
| General note | Advisor: Anthony S. Overton |
| Dissertation note | M.S. East Carolina University 2008 |
| Bibliography note | Includes bibliographical references (leaves 7-12, 28-33, 63-67). |
| Genre/form | dissertations. |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
