Concentrated Animal Feeding Operations and Urban Effects in Nitrogen Isotopic Signatures of Fish in a Coastal Oligohaline Estuary

This study was undertaken to assess the practicability of utilizing juveniles of a commercially important fish species as an indicator of spatial variation of nitrogen enrichment.  Juvenile white perch were collected throughout the Albemarle Estuarine System, NC from June-October 2005, and analyzed for nitrogen stable isotope enrichment (δ15N).  Enrichment of white perch muscle tissue was significantly lower in sub-systems surrounded by land which is less subjected to anthropogenic practices (e.g. animal farming operations and urbanization), such as the Alligator River Estuary, which is surrounded by federally protected wetlands.  Conversely, highest δ15N occurred at the mouths of the Chowan and Roanoke rivers, which drain substantial urban and Concentrated Animal Feed Operations. This study provides evidence of the feasibility of utilizing commercially valuable fish species to identify areas of possible concern related to nutrient loading within a coastal estuarine system.