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Full-Text Articles in Aquaculture and Fisheries

Spatiotemporal Variation In Flow-Dependent Recruitment Of Long-Lived Riverine Fish: Model Development And Evaluation, Daisuke Goto, Martin J. Hamel, Jeremy J. Hammen, Mathew L. Rugg, Mark A. Pegg, Valery E. Forbes Nov 2014

Spatiotemporal Variation In Flow-Dependent Recruitment Of Long-Lived Riverine Fish: Model Development And Evaluation, Daisuke Goto, Martin J. Hamel, Jeremy J. Hammen, Mathew L. Rugg, Mark A. Pegg, Valery E. Forbes

School of Biological Sciences: Faculty Publications

Abstract Natural flow regimes can play a major role as an overarching ecosystem driver in reproduction and recruitment of riverine fishes. Human needs for freshwater however have altered hydrology of many riverine systems worldwide, threatening fish population sustainability. To understand and predict how spatiotemporal dynamics of flow regimes influence reproductive and recruitment variability, and ultimately population sustainability of shovelnose sturgeon (Scaphirhynchus platorynchus), we develop a spatially explicit (1D) individual-based population model that mechanistically (via energetics-based processes) simulates daily activities (dispersal, spawning, foraging, growth, and survival). With field observations of sturgeon and habitat conditions in a major tributary of …


The Status Of Fishes In The Missouri River, Nebraska: Lake Sturgeon (Acipenser Fulvescens), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman Oct 2014

The Status Of Fishes In The Missouri River, Nebraska: Lake Sturgeon (Acipenser Fulvescens), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Lake Sturgeon (Acipenser fulvescens) occurrences in the Missouri River along Nebraska’s eastern border are historically sporadic and rare. Presently, the wild Lake Sturgeon population in this river reach may be extirpated. A Recovery Program initiated by the Missouri Department of Conservation (MDC) has stocked almost 150,000 hatchery-reared Lake Sturgeon into the lower Missouri River at several sites in Missouri. As a result, the number of Lake Sturgeon collected has increased. Since monitoring began in 2003, no Lake Sturgeon have been collected above Gavins Point Dam while 40 fish were collected downstream of Gavins Point Dam. The majority of …


The Status Of Fishes In The Missouri River, Nebraska: Pallid Sturgeon (Scaphirhynchus Albus), Kirk D. Steffensen, Dane A. Shuman, Robert A. Klumb, Sam Stukel Sep 2014

The Status Of Fishes In The Missouri River, Nebraska: Pallid Sturgeon (Scaphirhynchus Albus), Kirk D. Steffensen, Dane A. Shuman, Robert A. Klumb, Sam Stukel

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Anthropogenic alterations to the Missouri River have placed the Pallid Sturgeon (Scaphirhynchus albus) population in jeopardy and contributed to their listing as an endangered species. Pallid sturgeon were always less common than the sympatric Shovelnose Sturgeon (S. platorynchus); however, Pallid Sturgeon seemed to be more affected by river alterations as the river sturgeon ratio has become more skewed towards Shovelnose Sturgeon. Shortly after listing, population augmentation with hatchery produced Pallid Sturgeon began to supplement the diminishing wild population. Therefore, the objective of this study was to present the current population status of the Pallid Sturgeon in …


The Status Of Fishes In The Missouri River, Nebraska: Shovelnose Sturgeon (Scaphirhynchus Platorynchus), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman Sep 2014

The Status Of Fishes In The Missouri River, Nebraska: Shovelnose Sturgeon (Scaphirhynchus Platorynchus), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Shovelnose Sturgeon Scaphirhynchus platorynchus remains the most abundant riverine sturgeon species in North American despite the anthropogenic modifications that have occurred throughout their historic range; however, their populations have declined throughout Nebraska since the construction of Fort Randall and Gavins Point Dams. Therefore, the objective of this study was to present the current status of Shovelnose Sturgeon in the Missouri River along Nebraska’s border. Data was acquired from 2003 to 2012 from all reaches of the Missouri River along Nebraska’s eastern border. Catch rates of Shovelnose Sturgeon increased in a downstream trend and were highest in the reach below …


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 …