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Full-Text Articles in Physical Sciences and Mathematics
Movement Patterns Of A Federally Endangered Minnow In A Fragmented Desert River, Martinique J. Chavez
Movement Patterns Of A Federally Endangered Minnow In A Fragmented Desert River, Martinique J. Chavez
All Graduate Theses and Dissertations, Fall 2023 to Present
Fishes are unified in their need to move within the systems they occupy, and their movement patterns can be fundamental to their ecology and survival. Many large rivers in North America are fragmented by dams that modify natural flow regimes, compromise connectivity, and imperil freshwater fishes dependent on unrestricted movement in order to complete their life history. Coincident with widespread river fragmentation, are the declines of numerous endemic desert fishes in the American southwest. The Rio Grande Silvery Minnow (Hybognathus amarus, RGSM), has experienced a 95% reduction in its historical range and is now restricted to a highly …
Evaluating The Effectiveness Of Grassbed Treatments As Habitat For Juvenile Black Bass In A Drawdown Reservoir, D. R. Ratcliff, Wayne A. Wurtsbaugh, J. Zustak
Evaluating The Effectiveness Of Grassbed Treatments As Habitat For Juvenile Black Bass In A Drawdown Reservoir, D. R. Ratcliff, Wayne A. Wurtsbaugh, J. Zustak
Watershed Sciences Faculty Publications
Many reservoirs in arid regions experience highly variable water levels caused by seasonal inflow fluctuations and designated outflow requirements. At Shasta Lake, California, managers plant cereal-grain grassbeds on exposed drawdown shorelines to increase juvenile fish habitat, localize productivity, and increase invertebrate fish prey. To determine the efficacy of these plantings, the abundance of juvenile black basses Micropterus spp. (20–55 mm standard length) and the amount of periphyton and macroinvertebrate prey were compared among three treatment types: (1) planted grassbeds of cereal barley Hordeum vulgare; (2) artificial rope grassbeds, which eliminated physical deterioration and nutrient release; and (3) nonplanted control sites …
Fish Nutrient Cycling, Aquatic Respiration, And Terrestrial Insect Nutrient Subsidies To Lakes, Wayne A. Wurtsbaugh
Fish Nutrient Cycling, Aquatic Respiration, And Terrestrial Insect Nutrient Subsidies To Lakes, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
Mehner et al. (2005) reported that fish feeding on terrestrial insects could be important for nutrient budgets and cycling in lakes. They studied bleak (Alburnus alburnus) that fed largely on terrestrial insects, and they suggested that this contributed 2.1% of the lake's nutrient budget and that the subsequent excretion by the fish was equivalent to 11% of epilimnetic dissolved phosphorus concentrations. They concluded that nutrients delivered to lakes via terrestrial insects and recycled by fish would be most important for small lakes because of the large perimeter-to-area ratio between donor and recipient habitats. Fish may have important impacts …
An Empirical Model Of Gastric Evacuation Rates For Fish And An Analysis Of Digestion In Piscivorous Brown Trout, E. He, Wayne A. Wurtsbaugh
An Empirical Model Of Gastric Evacuation Rates For Fish And An Analysis Of Digestion In Piscivorous Brown Trout, E. He, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
The gastric evacuation rates of brown trout Salmo trutta (0.9–1.6 kg) feeding on fingerling rainbow trout Oncorhynchus mykiss (3.5–7.6 g) were measured in the laboratory at five temperatures (4.5, 9.0, 14.0, 19.0, and 22.5°C). Instantaneous gut evacuation rates (Re) increased exponentially with temperature (T): Re = 0.053se^0.073T, r^2 = 0.98; they varyied from 7%sh^–1 at 4.5°C to 29%sh^–1 at 22.5°C. Linear regressions described the relationship between time and qualitative measures of fish digestion, thus allowing investigators to determine how long an ingested fish would be identifiable at different temperatures. An analysis of published evacuation rates (N = 121) of 22 …