Physical Sciences and Mathematics Commons^™

Slides: Threats To Biological Diversity: Global, Continental, Local, J. Michael Scott

Shifting Baselines and New Meridians: Water, Resources, Landscapes, and the Transformation of the American West (Summer Conference, June 4-6)

Presenter: J. Michael Scott, U.S. Geological Survey, Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho

38 slides

Adding Nutrients To Enhance The Growth Of Endangered Sockeye Salmon: Trophic Transfer In An Oligotrophic Lake, Phaedra E. Budy, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Snake River sockeye salmon Oncorhynchus nerka, listed under U.S. law as endangered in 1991 in response to a decline in anadromous adult numbers, spend their first 1–2 years in Redfish Lake, Idaho, before migrating to the sea. To determine how nutrient enhancement might influence phytoplankton, zooplankton, and fish production, we performed fertilization experiments in large enclosures in this oligotrophic lake using juvenile kokanee (lacustrine O. nerka) as analogues for endangered sockeye salmon. Fertilization of the metalimnion substantially increased chlorophyll a (150%), phytoplankton biovolume (75%), primary productivity (250%), and zooplankton biomass (200%), and moderately increased fish growth (12%) over our control …

Simulated Growth And Production Of Endangered Snake River Sockeye Salmon: Assessing Management Strategies For The Nursery Lakes, Chris Luecke, Wayne A. Wurtsbaugh, Phaedra E. Budy, H. P. Gross

Watershed Sciences Faculty Publications

We examined the potential of employing a series of lake management strategies to enhance production of endangered Snake River sockeye salmon (Oncorhynchus nerka) in its historical nursery lakes in central Idaho. We used a combination of limnological sampling, experimentation, and simulation modeling to assess effects of lake fertilization and kokanee reduction on growth and survival of juvenile sockeye salmon. Juvenile sockeye salmon from a broodstock of this endangered species are being introduced into the lakes from 1995 to 1998. Results of our analyses indicated that several lakes were suitable for receiving broodstock progeny. Field experimentation and simulation modeling indicated that …