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Full-Text Articles in Aquaculture and Fisheries

Bioenergetics And Habitat Suitability Models For The Chinese Mystery Snail (Bellamya Chinensis), Danielle M. Haak May 2015

Bioenergetics And Habitat Suitability Models For The Chinese Mystery Snail (Bellamya Chinensis), Danielle M. Haak

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

Relatively little is known about the invasive Chinese mystery snail (Bellamya chinensis). This research aims to elucidate some of the mystery surrounding this species. First, we place the species in context with other invasive freshwater snails of the USA and Canada, identifying current information gaps, categorizing shared characteristics among families and species, and comparing functional roles and ecological effects of freshwater snails. We conclude that more focus needs to be directed to regulating the aquarium, pet, and food trades if we are serious about preventing future invasions. Next, we develop a bioenergetics model for the species by quantifying …


Ecology And Management Of Superabundant Fish Populations, Nathaniel T. Stewart May 2015

Ecology And Management Of Superabundant Fish Populations, Nathaniel T. Stewart

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

Fish population biomasses can reach extreme levels; we term these populations superabundant fish populations. Superabundant fish populations may negatively affect aquatic communities and anglers, necessitating the effective management of the superabundant fish populations. However, there are gaps in our understanding of these populations. The gaps in our understanding hamper our ability to predict effects on valuable sportfisheries and to effectively manage superabundant fish populations. The overall goal of my thesis research is to provide further insight into the ecology of superabundant fish populations and to provide information that will aid in their effective management. First, we described a new method …


Genetic And Morphological Variation In Ecuadorian Astroblepid Catfishes, Katherine M. Lawry May 2015

Genetic And Morphological Variation In Ecuadorian Astroblepid Catfishes, Katherine M. Lawry

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

The Andean ichthyofauna remains a poorly understood component of Neotropical biodiversity, and stands in stark contrast to the lowland ichthyofauna in terms of number of species and range of distribution. The Climate Variability Hypothesis (CVH) predicts rapid turnover of species along elevational gradients in tropical climates, but it remains unclear whether stream fishes follow this pattern. Astroblepid catfishes represent a distinctive assemblage of species that inhabit high elevation streams throughout the Andes from Panama to Bolivia, and constitute the only native fish family present in the Ecuadorian highland region. In this research, population samples of Astroblepids collected throughout Ecuador’s Napo …


Response Of Large River Fishes To A Prolonged High Water Event In The Missouri River, Nebraska, Nicholas Paul Hogberg May 2014

Response Of Large River Fishes To A Prolonged High Water Event In The Missouri River, Nebraska, Nicholas Paul Hogberg

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

Regulation and modification of large rivers to accommodate human uses have been a root cause of freshwater biodiversity declines. The Missouri River is among the most drastically-altered large river systems in North America, with a series of mainstem impoundments in the upper watershed altering flow characteristics downstream, and channelization throughout the lower river homogenizing instream habitat and reducing off-channel habitat. Precipitation events during the winter and spring 2010-2011 caused flooding of the greatest magnitude and duration since reservoir completion. The large magnitude and long duration of this flood made it unlike any flood in recent history and provided a unique …


Accuracy Or Precision: Implications Of Sample Design And Methodology On Abundance Estimation, Lucas K. Kowalewski May 2014

Accuracy Or Precision: Implications Of Sample Design And Methodology On Abundance Estimation, Lucas K. Kowalewski

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

Estimation of population size by spatially replicated counts (point-count method) has been used for many large-scale animal-monitoring programs, yet its application in aquatic environments has been limited. Multiple site-specific estimates of abundance can be averaged and combined with covariate data to predict total abundance across an area of interest. Covariate data also provide an understanding of the relationship between abundance and habitat use, which is a fundamental interest of many animal-population investigations. Design of sampling scenarios for point-count population-estimate surveys can influence the accuracy and precision of the population estimate. The first objective of this study was to examine how …


Walleye And White Bass Recruitment In Southwest Nebraska Irrigation Reservoirs, Jason Andrew Deboer Nov 2013

Walleye And White Bass Recruitment In Southwest Nebraska Irrigation Reservoirs, Jason Andrew Deboer

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

Walleye Sander vitreus and white bass Morone chrysops are among the most popular sportfish in the reservoirs of the Great Plains. Despite considerable effort by the Nebraska Game and Parks Commission stocking walleye and managing reservoirs for walleye and white bass, populations of walleye and white bass in southwest Nebraska reservoirs are dynamic, as erratic recruitment has led to “boom and bust” fisheries for these two species. We investigated 1) factors regulating walleye and white bass recruitment during an 18-year period at five reservoirs, and 2) walleye spawning ecology at two reservoirs that differ in their degree of environmental variability. …


Retention, Movement, And The Biotic Response To Large Woody Debris In The Channelized Missouri River, Michael W. Archer Jan 2010

Retention, Movement, And The Biotic Response To Large Woody Debris In The Channelized Missouri River, Michael W. Archer

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

Large woody debris (LWD) is an important component of a healthy aquatic ecosystem. However, little is known about the dynamics of LWD in a large, channelized river such as the Missouri River. My objectives were to first, assess the abundance of LWD found along the channelized portion of the Missouri River. Second, I documented movement of LWD that entered the river. Lastly, using PRIMER software I analyzed what effect, if any, river segments, bend types, and LWD had on the community composition of the macroinvertebrate and fish that inhabit the river. Abundance of LWD was greater along bends that have …