The Influence of Nitrogen Limitation on d15N and Carbon : Nitrogen Ratios in Sediments from Sockeye Salmon Nursery Lakes in British Columbia, Canada
Document Type
Article
Journal/Book Title/Conference
Limnology and Oceanography
Volume
51
Issue
5
Publisher
Wiley Blackwell
Publication Date
9-14-2006
Keywords
sockeye salmon, d15N, nitrogen ratios, British Columbia, Carbon
Abstract
Carbon (C) and nitrogen (N) elemental and nitrogen isotopic ratios were determined for bulk organic matter in surface sediments of 11 sockeye salmon (Onchorynchus nerka) nursery lakes in British Columbia, Canada. Chitinous exoskeletons of Bosmina spp. were also picked from the sediments and analyzed for Δ15N. The correlation between salmon escapement (spawner abundance) and bulk organic Δ15N confirms the importance of marine‐derived nitrogen to the study lakes. The relation between sediment Δ15N and escapement, however, suggests that simple mixing models may significantly underestimate spawner abundance in nitrogen‐limited lakes. In addition, the use of sediment and chitin Δ15N and C:N data to characterize lake‐specific differences demonstrates that sediment isotope signatures are dependent on attendant nitrogen deficiency. The sediment C:N ratio, on its own, provides a sensitive measure of nutrient status in these lakes. This finding provides an alternate additional interpretation of C:N ratios that may be more appropriate in large lakes where terrestrial contributions to the central basin are insignificant.
Recommended Citation
Brahney, Janice, Bos, Darren G., Pellatt, Marlow G., Edwards, Thomas W. D., Routledge, Richard, (2006), The influence of nitrogen limitation on d15N and carbon : nitrogen ratios in sediments from sockeye salmon nursery lakes in British Columbia, Canada, Limnology and Oceanography, 51, doi: 10.4319/lo.2006.51.5.2333.
