You are here:
Quantifying intra-population variability in stable isotope data for spotted seatrout (cynoscion nebulosus)
FULFORD, R. S. AND K. DILLON. Quantifying intra-population variability in stable isotope data for spotted seatrout (cynoscion nebulosus). FISHERIES BULLETIN. U.S. Department of Commerce, Washington, DC, 111(2):111-121, (2013).
Stable isotope (SI) values of carbon (δ13C) and nitrogen (δ15N) are useful for determining the trophic connectivity between species within an ecosystem, but interpretation of these data involves important assumptions about sources of intrapopulation variability. We compared intrapopulation variability in δ13C and δ15N for an estuarine omnivore, Spotted Seatrout (Cynoscion nebulosus), to test assumptions and assess the utility of SI analysis for delineation of the connectivity of this species with other species in estuarine food webs. Both δ13C and δ15N values showed patterns of enrichment in fish caught from coastal to offshore sites and as a function of fish size. Results for δ13C were consistent in liver and muscle tissue, but liver δ15N showed a negative bias when compared with muscle that increased with absolute δ15N value. Natural variability in both isotopes was 5–10 times higher than that observed in laboratory populations, indicating that environmentally driven intrapopulation variability is detectable particularly after individual bias is removed through sample pooling. These results corroborate the utility of SI analysis for examination of the position of Spotted Seatrout in an estuarine food web. On the basis of these results, we conclude that interpretation of SI data in fishes should account for measurable and ecologically relevant intrapopulation variability for each species and system on a case by case basis.
Quantifying intra-population variability in stable isotope data for an omnivorous estuarine fish
URLs/Downloads:Quantifying intra-population variability in stable isotope data for spotted seatrout (cynoscion nebulosus) Exit
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB
GULF ECOLOGY DIVISION
ECOSYSTEM ASSESSMENT BRANCH