Physical Sciences and Mathematics Commons^™

Habitat Heterogeneity In Nebraska Streams And Distribution Prediction For Tier-1 Cyprinids Using Multi-Scale Modeling Of Fluvial And Landscape Features, Connor P. Hart

School of Natural Resources: Dissertations, Theses, and Student Research

Multiscale environmental processes determine in-stream habitat conditions which drive species distributions. Habitat constitutes the physical template upon which ecological processes occur and species conduct life stage activities. Habitat heterogeneity promotes biodiversity of aquatic systems. Stream classification informs freshwater conservation by providing a useful framework to account for habitat heterogeneity, often based on landscape regions of similar environmental processes. A greater understanding of landscape-based classification frameworks as means to classify stream systems may improve understanding of drivers of biodiversity. Using Nebraska as a case study, on a statewide scale, objectives were 1) to characterize habitat availability for several at-risk fish species, …

Population Dynamics Of The Freshwater Mussel Lampsilis Cardium Reintroduced In Nebraska, Lindsay M. Ohlman

School of Natural Resources: Dissertations, Theses, and Student Research

The global decline of native freshwater mussels has accelerated conservation projects that preserve and restore populations, but the complex life histories among species challenges biologists in determining the most effective management strategies. This study details the conservation of plain pocketbook, a Tier I threatened mussel species in Nebraska that was artificially propagated and reintroduced into 13 sites from autumn 2016 to summer 2017. The objectives of this study were: 1) determine how handling influences mussels, and 2) evaluate mussel growth and survival following introductions.

We conducted a laboratory experiment with age-2 plain pocketbook to assess the effects of handling on …

Groundwater Declines Are Linked To Changes In Great Plains Stream Fish Assemblages, Joshuah S. Perkin, Keith B. Gido, Jeffrey A. Falke, Kurt D. Fausch, Harry Crockett, Eric R. Johnson, John Sanderson

United States Geological Survey: Staff Publications

Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950–2010) and prospective (2011–2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within …

An Environmental Oestrogen Disrupts Fish Population Dynamics Through Direct And Transgenerational Effects On Survival And Fecundity, Adam R. Schwindt, Dana L. Wrinkelman, Kristen Keteles, Mark Murphy, Alan M. Vajda

United States Environmental Protection Agency: Staff Publications

1. Increased need for water and projected declines in precipitation due to climate change could leave waterways increasingly dominated by wastewater effluent. Understanding how components of wastewater influence fish populations is necessary for effective conservation and management. Despite research demonstrating effects of oestrogens, such as 17a-ethynylestradiol (EE2), on fish physiology and population failure, the generality of population responses is uncertain and the underlying mechanisms affecting population declines are unknown. EE2 is the steroid oestrogen in human contraceptive pills and has been measured up to 11 ng L ^-1 in the environment.

2. We identify disrupted population dynamics due to direct …

Influence Of Light And Nutrients On Atrazine Toxicity To Freshwater Algae, Crystal J. Hansen

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Effects Of Binary Combinations Of Herbicides On Freshwater Algae, Jill K. Taylor

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.