title: Carbon and nitrogen isotope ratios of juvenile winter flounder as indicators of inputs to estuarine systems.
abstract: Stable carbon and nitrogen isotope ratios were measured in young-of-the-year (YOY) winter flounder, Pseudopleuronectes americanus, collected from several Rhode Island, USA estuarine systems. These included three coastal lagoons, an estuarine river and Narragansett Bay. The δ(13)C trends observed along transects in several systems showed isotopically depleted terrestrial signals in the upper reaches of the estuaries. Significant differences (P<0.05) in δ(15)N were observed among all estuarine systems and these differences correlated (P<0.01) with human population densities in the watersheds. Although Narragansett Bay has a strong north-south gradient in nutrient concentrations this trend was not reflected in flounder δ(15)N. The northernmost station with the highest nutrient concentrations unexpectedly had significantly lower δ(15)N values. Depleted δ(15)N values at this nutrient-rich station may indicate that concentration-dependent fractionation needs to be considered when using nitrogen isotope ratios in biota to monitor anthropogenic nitrogen inputs in systems with high nitrogen loadings.
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882, United States. Electronic address: pruell.richard@epa.gov.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Pruell
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882, United States.
authors.forename: Bryan K
authors.initials: BK
authors.lastname: Taplin
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D063366:Estuaries; D005432:Flounder / Q000378:metabolism; D006801:Humans; D009584:Nitrogen / Q000032:analysis; D009587:Nitrogen Isotopes / Q000032:analysis*; D011156:Population Density; D012237:Rhode Island; D045483:Rivers
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D009584:Nitrogen
keywords: Estuaries; Fish; Stable carbon isotopes; Stable nitrogen isotopes; Winter flounder