Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Life Sciences

The Role Of Anadromous Sockeye Salmon (Oncorhynchus Nerka) In The Nutrient Loading And Productivity Of The Sawtooth Valley Lakes, Idaho, H. P. Gross, Wayne A. Wurtsbaugh, Chris Luecke Jan 1998

The Role Of Anadromous Sockeye Salmon (Oncorhynchus Nerka) In The Nutrient Loading And Productivity Of The Sawtooth Valley Lakes, Idaho, H. P. Gross, Wayne A. Wurtsbaugh, Chris Luecke

Watershed Sciences Faculty Publications

We constructed a simulation model for Redfish Lake, Idaho, using water budget and nutrient loading measurements, to predict the dependence of lake production on nutrients from the watershed, precipitation, lake fertilization, and marine-derived nutrients from sockeye salmon Oncorhynchus nerka, which historically have reared in the lake. We also used the model to simulate different management scenarios to help restore the endangered Snake River sockeye salmon. The model and other empirical evidence indicated that even before hydropower dams were present in the migration corridor, marine-derived nutrients were not of major importance to lake production, contributing only about 3% of the annual …


Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala Jan 1997

Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala

Watershed Sciences Faculty Publications

We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both Oncorhynchus nerka) in Sawtooth Valley lakes of Idaho during September 1991 and 1992. Abundance of O. nerka varied among the four lakes containing this species (12,500–257,000) and varied between years in Redfish Lake (86,400 in 1994 and 241,000 in 1992) and Alturas Lake (230,000 in 1991 and 257,000 in 1992). In Alturas Lake, where piscivore densities were high and zooplankton densities were low, small acoustic targets (≤18 cm …


Nutrient Limitation Of Oligotrophic Sockeye Salmon Lakes Of Idaho (Usa), Wayne A. Wurtsbaugh, H. P. Gross, Chris Luecke, Phaedra E. Budy Jan 1997

Nutrient Limitation Of Oligotrophic Sockeye Salmon Lakes Of Idaho (Usa), Wayne A. Wurtsbaugh, H. P. Gross, Chris Luecke, Phaedra E. Budy

Watershed Sciences Faculty Publications

"Phytoplankton production in lake ecosystems is frequently controlled by amounts of nitrogen and phosphorus (Smith 1982, Elser et al. 1990), as well as minor- and micro-nutrients (Wurtsbaugh & Horne 1983, Wurtsbaugh 1988, Lovstad & Bjorndalen 1990). Nutrient limitation is often studied to determine which nutrient(s) should be reduced to control lake eutrophication (Schindler 1974(. Conversely, nutrients have been used for decades to stimulate plankton and, subsequently, fish production in aquaculture (Bardach et al. 1972). More recently, lake fertilization has been used to augment salmon runs for commercial exploitation (Hyatt & Stockner 1985, lye et al. 1988), and it has been …


Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr. May 1977

Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rodent densities were estimated in the major vegetation types of the Snake River Birds of Prey Natural Area in 1975 and 1976 by a combination of live-trapping and kill-trapping. Only deer mice (Peromyscus maniculatus) were numerous enough to permit reliable density estimates. Relative densities of other rodent species were indicated by kill-trap capture rates. Densities of deer mice correlated well (r = 0.99) with kill-trap capture rates. The use of kill-trapping in place of live-trapping in 1976 permitted extensive sampling throughout the 1930 km2 study area. Differences were found among the major vegetation and land-use types in …