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Full-Text Articles in Aquaculture and Fisheries
Adding Nutrients To Enhance The Growth Of Endangered Sockeye Salmon: Trophic Transfer In An Oligotrophic Lake, Phaedra E. Budy, Chris Luecke, Wayne A. Wurtsbaugh
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 …
Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh
Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
We monitored the diet and growth of stocked rainbow trout Oncorhynchus mykiss in two Utah reservoirs during 1986 and 1989–1990. For the first month after stocking, juvenile rainbow trout in both reservoirs fed extensively on large Daphnia spp. In East Canyon Reservoir where Daphnia were abundant, this pattern continued throughout the summer, fall, and winter. Growth of rainbow trout in East Canyon Reservoir was generally good throughout 1989–1990. In Causey Reservoir, where Daphnia were less abundant and smaller, rainbow trout fed progressively less on smaller Daphnia throughout the summer, fall, and winter, while other prey items (snails, aquatic insects, and …
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
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 …
Growth And Activity Of Juvenile Mosquitofish: Temperature And Ration Effects, Wayne A. Wurtsbaugh, J. Cech
Growth And Activity Of Juvenile Mosquitofish: Temperature And Ration Effects, Wayne A. Wurtsbaugh, J. Cech
Watershed Sciences Faculty Publications
The effects of constant temperatures (10, 15, 20, 25, 30, and 35 C) and ration size on the growth rates and activity of juvenile mosquitofish Gambusia affinis (mean wet weight, about 20 mg) were measured in laboratory experiments. On ad libitum rations of Tubifex spp. worms, food-consumption rates of mosquitofish were very high, ranging from 7% dry body weight/day at 10 C to 83%/day at 35 C. Growth increased from 0% dry body weight/day at 10 C to 21%/day at 30 C and declined slightly at 35 C. Gross efficiencies (100 growth/food consumption) increased from 0 at 10 C to …