Thesis (Ph. D.)--Michigan State University. Dept. of Fisheries and Wildlife, 2008. / Title from PDF t.p. (viewed on July 23, 2009) Includes bibliographical references (p. 160-179). Also issued in print.

The lake sturgeon, Acipenser fulvescens, was once abundant throughout Canada and the United States, however, high commercial harvests and habitat alterations have dramatically reduced most populations. The species was extirpated from many rivers that it once inhabited, and has been designated as threatened or endangered throughout its range. Currently, few healthy lake sturgeon populations remain and the species is receiving considerable attention with respect to its protection and recovery. Although considerable effort is underway to conserve the species, several factors, including over-harvest and habitat alteration, pollution and a general lack of understanding about lake sturgeon ecology and behavior continue to hamper recovery efforts. This thesis examined the ecology and behavior of juvenile lake sturgeon within a 41 km long impounded section of the Winnipeg River, a large river in the Canadian Shield, over a three-year period (2006 – 2008). Habitat preferences, species associations, diet, and movement were described on a seasonal basis. Biological characteristics were also described for juvenile lake sturgeon within the study area. Studies presented in this thesis are among the first conducted for juveniles of this species in the Hudson Bay drainage basin, and from large riverine environments in general. Results are important, not only for improving our understanding of lake sturgeon at the juvenile life history stage, but for facilitating further research. In particular, future research studies identified in the final chapter have the potential to enhance our understanding of factors influencing mortality during the early life history stages of the lake sturgeon, and therefore, greatly enhance recovery efforts.

Climate change effects have been documented in the Canadian Prairie Provinces. Temperature is predicted to continue to increase, and precipitation patterns are changing. As a result, river flow is anticipated to diminish. The South Saskatchewan River (SSR) provides vital habitat to lake sturgeon. Lake sturgeon are currently endangered or threatened across most of their native range, prompting provincial governments to develop management strategies. As lake sturgeon habitat is dependent on flow, understanding climate change impacts on flow conditions in the SSR will be an important component of their long-term management strategy for lake sturgeon. I have developed empirical models based on regional climate variables (temperature and precipitation) to predict in-stream flow. These models were developed using general linear modeling and Akaikes Information Criterion (AIC). Future in-stream flow was predicted by extracting key variables from 5 different GCM’s and inserting the variables into the predictive flow models. These future flow scenarios were coupled with habitat suitability indices developed to assess changes in sturgeon habitat developed by the Water Security Agency and Department of Fisheries and Oceans Canada. Flow scenarios predict a decrease in the habitat of most life stages (spawning, juvenile, adult and subadult), but an increase in fry habitat. These models will represent a novel advancement for sturgeon management in Western Canada.

The lake sturgeon, Acipenser fulvescens, was once abundant throughout Canada and the United States, however, high commercial harvests and habitat alterations have dramatically reduced most populations. The species was extirpated from many rivers that it once inhabited, and has been designated as threatened or endangered throughout its range. Currently, few healthy lake sturgeon populations remain and the species is receiving considerable attention with respect to its protection and recovery. Although considerable effort is underway to conserve the species, several factors, including over-harvest and habitat alteration, pollution and a general lack of understanding about lake sturgeon ecology and behavior continue to hamper recovery efforts. This thesis examined the ecology and behavior of juvenile lake sturgeon within a 41 km long impounded section of the Winnipeg River, a large river in the Canadian Shield, over a three-year period (2006 – 2008). Habitat preferences, species associations, diet, and movement were described on a seasonal basis. Biological characteristics were also described for juvenile lake sturgeon within the study area. Studies presented in this thesis are among the first conducted for juveniles of this species in the Hudson Bay drainage basin, and from large riverine environments in general. Results are important, not only for improving our understanding of lake sturgeon at the juvenile life history stage, but for facilitating further research. In particular, future research studies identified in the final chapter have the potential to enhance our understanding of factors influencing mortality during the early life history stages of the lake sturgeon, and therefore, greatly enhance recovery efforts.

The lake sturgeon (Acipenser fulvescens), is a species with considerable ecological, social and economic value. Unfortunately, over-exploitation and habitat alteration have led to the collapse of lake sturgeon fisheries across North America. Based on conservation concerns, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) identified eight designatable units (DUs) among Canadian populations of lake sturgeon using the limited information available. These DUs are intended to represent taxonomically, genetically, geographically, or biogeographically distinct units below the species level. In this study, the genetic structuring among 20 lake sturgeon localities was examined using nine microsatellite loci. Lake sturgeon localities conformed to hierarchical partitioning of genetic diversity, with the greatest genetic divergence between localities in the Great Lakes and Hudson Bay drainages. Finally, minimal divergences among the current DUs warrant adjustment of lake sturgeon DU boundaries, to more appropriately reflect the distribution of genetic differentiation among lake sturgeon localities.

The lake sturgeon (Acipenser fulvescens), is a species with considerable ecological, social and economic value. Unfortunately, over-exploitation and habitat alteration have led to the collapse of lake sturgeon fisheries across North America. Based on conservation concerns, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) identified eight designatable units (DUs) among Canadian populations of lake sturgeon using the limited information available. These DUs are intended to represent taxonomically, genetically, geographically, or biogeographically distinct units below the species level. In this study, the genetic structuring among 20 lake sturgeon localities was examined using nine microsatellite loci. Lake sturgeon localities conformed to hierarchical partitioning of genetic diversity, with the greatest genetic divergence between localities in the Great Lakes and Hudson Bay drainages. Finally, minimal divergences among the current DUs warrant adjustment of lake sturgeon DU boundaries, to more appropriately reflect the distribution of genetic differentiation among lake sturgeon localities.

Thesis (M.S.)--Michigan State University, Fisheries and Wildlife, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 95-106). Also issued in print.

Thesis (M.S.)--Michigan State University. Dept. of Fisheries and Wildlife, 2008. / Title from PDF t.p. (viewed on Aug. 7, 2009) Includes bibliographical references (p. 62-64). Also issued in print.

No description available.

Rivers are inherently dynamic environments with fluctuations in water quality, hydrology, connectivity and geomorphology. Though geomorphology has long been recognized as an important driver defining biological, ecological, and physical habitat characteristics of rivers, a readily applied classification tool that links such characteristics has been lacking. The Geomorphic Response Unit (GRU) method provides a novel approach to identifying large scale patterns in geomorphic character that provide a link between the hydrological regime and different habitat types to which species respond. Specifically, I investigated whether Geomorphic Types and GRUs are related to the distribution and abundance of different fish species, reflecting unique physical habitat characteristics of individual GRUs. The thesis chapters are manuscript based. The second chapter identifies relationships between specific Geomorphic Types, identified using the Geomorphic Response Unit (GRU) methodology, and Lake Sturgeon overwintering locations in the South Saskatchewan and Saskatchewan Rivers. Habitat selection ratios suggest that Lake Sturgeon in the Upper South Saskatchewan River significantly selected for one of seven possible Types for overwintering. Logistic regression results found both Type 0 and Type 4 predicted significantly higher Sturgeon presence than all other Types (P = < 2e-16 for both). The third chapter examines relationships between GRUs and abundance of both mature and immature Carmine Shiner in the Birch River, Manitoba. Differences in the median mature Carmine Shiner CPUEs among the GRUs are not statistically different (Kruskal-Wallis test H =1.723; df = 3, p value = 0.632), though interesting qualitative relationships were identified which may inform further studies. The fourth chapter investigates whether GRUs derived using a large scale network approach are linked to the abundance of specific fish species in the Assiniboine River, Manitoba. A Kruskal-Wallis test identified significant differences in CPUE among GRUs for 10 of 14 tested species. Post-hoc pairwise multiple comparisons using Dunn’s Method with Bonferroni p-value correction for multiple paired tests isolated the GRUs that were different from one another. Overall, my findings suggest that Geomorphic Response Units (GRU) are an effective means of identifying patterns in geomorphic structure within Prairie Rivers at both reach and segment scales. Further, I identified links between both Geomorphic Types and GRUs and patterns in abundance of various fish species covering a wide range of life history traits. These findings suggest that GRUs have potential as a valuable fisheries habitat management tool, increasing efficiency of monitoring efforts through quantification of habitat availability, connectivity, and complexity in Prairie River systems.