USGS Home
Contact USGS
Search USGS

Search fish passage bibliography

Kline, T. C., Jr., J. J. Goering, O. A. Mathisen, P. H. Poe, P. L. Parker and R. S. Scalan (1993). Recycling of elements transported upstream by runs of Pacific salmon: II.Δ¹⁵N and Δ ¹³C evidence in the Kvichak River watershed, Bristol Bay, southwestern Alaska. Canadian Journal of Fisheries and Aquatic Sciences. 50:2350-2365.

Biota Δ¹⁵N and Δ ¹³C values (deviations from recognized isotope standards) from Iliamna Lake (a major anadromous sockeye salmon Oncorhynchus nerka nursery lake supporting peak-year runs >10 million) and several other anadromous-salmon-free lakes in the Kvichak River watershed, Bristol Bay, southwestern Alaska, were compared to determine the significance of marine-derived nitrogen (MDN) delivered by returning adult salmon. Biota in Iliamna Lake had higher Δ¹⁵N compared with control lakes, verifying a mixing model correlating Δ¹⁵N with MDN. Periphyton Δ¹⁵N values reflected localized input from populations of spawning salmon. Juvenile sockeye MDN varied in response to escapement size, suggesting the importance of large escapements (>10 million) for maintaining a predominantly MDN lacustrine N pool. Other resident fishes showed shifts in Δ¹⁵N between years of high and low escapement. The dual-isotope approach, using Δ¹⁵N and Δ¹³C together, suggested that fish production is primarily dependent on limnetic primary and secondary production. The dual-isotope approach indicated that the coast range sculpin Cottus aleuticus was the only fish with an appreciable dietary component consisting of salmon eggs or emergent fry.