• Media type: E-Article
  • Title: Ecological, Landscape, and Climatic Regulation of Sediment Geochemistry in North American Sockeye Salmon Nursery Lakes: Insights for Paleoecological Salmon Investigations
  • Contributor: Selbie, Daniel T.; Finney, Bruce P.; Barto, David; Bunting, Lynda; Chen, Guangjie; Leavitt, Peter R.; Maclsaac, Erland A.; Schindler, Daniel E.; Shapley, Mark D.; Gregory-Eaves, Irene
  • Published: American Society of Limnology and Oceanography, 2009
  • Published in: Limnology and Oceanography, 54 (2009) 5, Seite 1733-1745
  • Language: English
  • DOI: 10.4319/lo.2009.54.5.1733
  • ISSN: 0024-3590; 1939-5590
  • Origination:
  • Footnote:
  • Description: We used multiple linear regressions across a Northeast Pacific region 56-lake set to examine the influence of sockeye salmon spawner densities and limnological, climatic, and watershed characteristics on sediment stable nitrogen isotope (δ¹⁵N) and C: N signatures, geochemical proxies used in paleolimnological reconstructions of prehistoric salmon abundances. Across all sites (n = 56), sedimentary C:N was primarily related to variables reflecting allochthonous organic matter and nutrient fluxes, with 67% of the variance explained by watershed vegetation type, watershed area, mean slope, and salmon spawner densities. In a subset of sites with nutrient data (n = 41), 63% of variance in C:N was explained by precipitation and watershed vegetation type. Sediment δ¹⁵N was most strongly related to salmon spawner densities, but C: N and watershed area: lake area ratios explained significant residual variance (total 55%). In sites with nutrient data, salmon spawner densities, vegetation type, and spring nitrate explained 62% of the variance in δ¹⁵N. Sediment C: N and δ¹⁵N values exhibited distinct interregional variation, typically varying inversely. Regional δ¹⁵N-salmon density relationships (regression slopes) varied strongly with total annual precipitation (r²=0.89, p=0.016, n=5), suggesting watershed organic matter and nutrient loading vary predictably in relation to regional biogeoclimatic conditions. Our findings demonstrate that paleolimnological analyses are useful for quantitative reconstruction of past salmon densities; however, inferences regarding past salmon populations must consider the factors regulating influxes of nitrogen from watershed sources.
  • Access State: Open Access