No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 176-190). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 176-190). Also available on the Internet.

Thesis (M.S.)--Missouri State University, 2008. / "August 2008." Includes bibliographical references (leaves 19-23). Also available online.

No description available.

Minnows and darters are the most imperiled freshwater fish species in North America as a result of habitat degradation and restricted ranges, which often results in isolated populations. The Candy Darter Etheostoma osburni was recently listed as Endangered and may represent a suite of other imperiled fishes in terms of their ecology, life-history traits, and conservation needs. I examined the effects of microhabitat features, sampling effort, species abundance and morphology on riffle-dwelling species. My results confirm many of the well-known influences on detection, while adding to the knowledge of species-specific attributes that can influence detection of common riffle species. Using physical marking and molecular methods, I describe movement patterns and provide insight into the spatial distribution of related pairs and reproductive contribution of the endangered Candy Darter. Minimum detected movements of adults were greater for molecular methods than for visual markings. Indirect movements inferred from the spatial extent between related pairs indicated that parents and offspring move along their entire 18.8-km distribution in Stony Creek, while individual parents and offspring in Laurel Creek move throughout half of their 4.25-km distribution. Additionally, I provide evidence that the lifetime reproductive contribution of Candy Darter is greater than previously described. Using microsatellite DNA markers, I describe population genetic structure and estimate effective population sizes of the four extant populations of Candy Darter in Virginia and provide insight into which populations may be successful as sources for reintroduction or translocation efforts. The four extant populations in Virginia are demographically isolated, but results also suggest historical connectivity. Effective population estimates for all populations were less than the recommended 500 to maintain evolutionary potential, but three populations numbered > 130, indicating they may be viable options for source populations for translocations. My results suggest that all populations may benefit from translocations to overcome genetic drift and inbreeding and to safeguard the historical genetic variation of the species. / Master of Science / Minnows and darters are the most imperiled freshwater fish species in North America as a result of habitat degradation and restricted ranges, which often results in isolated populations. The Candy Darter Etheostoma osburni was recently listed as Endangered and may represent a suite of other imperiled fishes in terms of their ecology, life-history traits, and conservation needs. I examined the effects of microhabitat features, sampling effort, species abundance and morphology on riffle-dwelling species. My results confirm many of the well-known influences on detection, while adding to the knowledge of species-specific attributes that can influence detection of common riffle species. Using physical marking and molecular methods, I describe movement patterns and provide insight into the spatial distribution of related pairs and reproductive contribution of the endangered Candy Darter. Minimum detected movements of adults were greater for molecular methods than for visual markings. Indirect movements inferred from the spatial extent between related pairs indicated that parents and offspring move along their entire 18.8-km distribution in Stony Creek, while individual parents and offspring in Laurel Creek move throughout half of their 4.25-km distribution. Additionally, I provide evidence that adult Candy Darter successfully reproduce over a greater number of years than previously described. Using microsatellite DNA markers, I describe population genetic structure and estimate the number of individuals contributing the gene pool of the four extant populations of Candy Darter in Virginia and provide insight into which populations may be successful as sources for reintroduction or translocation efforts. The four extant populations in Virginia are reproductively isolated, but results also suggest historical connectivity. The numbers of individuals contributing to population-specific gene pools were less than the recommended 500 to maintain evolutionary potential, but three populations numbered > 130, indicating they may be viable options for source populations for translocations. My results suggest that all populations may benefit from translocations to overcome genetic drift and inbreeding and to safeguard the historical genetic variation of the species.

Municipal wastewater effluent (MWWE) has the potential for aquatic degradation, as it is the largest, per volume, anthropogenic discharge in Canada and other areas in the world. With an increasing population in many areas, such as Southern Ontario, there is concern that infrastructure of wastewater treatment facilities will not be able to maintain adequate treatment and prevent further degradation of the environment. The Grand River watershed, in Southern Ontario, is predicted to have its population increase to 1.2 million people by 2031 (from 780,000 people in 2001). Although wastewater treatment has improved, concern remains for receiving environments due to inadequate treatment (i.e. Kitchener) and minimal dilution (i.e. Guelph). This research was conducted to understand current impacts of MWWE in the Grand River watershed on fish communities to support future management and protection. Study sites upstream and downstream were chosen for their proximity to the Guelph, Kitchener, and Waterloo MWWE outfalls, similarity in habitat, and wadeability. Habitat analysis indicated that there were no large physical differences among sites. Fish communities were collected in a standardized method with a backpack electroshocker at each site (six randomly selected 10 m by 10 m sub-sites for 5 min). Greenside Darter (Etheostoma blennioides) and Rainbow Darter (E. caeruleum), the most abundant species, were also analyzed for stable isotope signatures (δ13C and δ15N) at each site. Downstream of the Guelph outfall there were no changes in mean total catch per unit effort (CPUE) or mean total mass. Changes to diversity, resilience, and tolerance in the fish community were attributed to a decreased abundance of Greenside Darter and increased abundance of Rainbow Darter. Downstream of the Kitchener discharge, there was a trend towards decreasing mean total CPUE, especially for darter species, and an increase in mean total mass due to a community shift to larger species including Catostomids and Centrarchids. The changes in abundance of Rainbow Darter, Catostomids, and Centrarchids among reference and Kitchener MWWE exposed sites explained the pattern in resilience, tolerance, and diet classifications. Lower diversity downstream of all three MWWE outfalls can be attributed to the increase in Rainbow Darter abundance. Stable isotope signatures (δ13C and δ15N) of Greenside Darter did not change downstream of the Guelph and Waterloo discharges, but signatures of Rainbow Darter increased immediately below the two outfalls. This shift may be due to the Rainbow Darter being able to take advantage of a change in the environment (i.e. food availability), resulting in its increased abundance and changes in isotopic signature. Directly downstream of the Kitchener outfall both darter species had an increase in δ13C and a large decrease in δ15N, likely due to high nutrient inputs from the outfall. The Kitchener wastewater discharge is also associated with a decrease in abundance of fish and a shift in community structure. MWWEs are currently affecting the aquatic environment, including fish communities in the Grand River watershed. Future investments in infrastructure and watershed management should be made to mitigate degradation of water quality in this watershed.

Municipal wastewater effluent (MWWE) has the potential for aquatic degradation, as it is the largest, per volume, anthropogenic discharge in Canada and other areas in the world. With an increasing population in many areas, such as Southern Ontario, there is concern that infrastructure of wastewater treatment facilities will not be able to maintain adequate treatment and prevent further degradation of the environment. The Grand River watershed, in Southern Ontario, is predicted to have its population increase to 1.2 million people by 2031 (from 780,000 people in 2001). Although wastewater treatment has improved, concern remains for receiving environments due to inadequate treatment (i.e. Kitchener) and minimal dilution (i.e. Guelph). This research was conducted to understand current impacts of MWWE in the Grand River watershed on fish communities to support future management and protection. Study sites upstream and downstream were chosen for their proximity to the Guelph, Kitchener, and Waterloo MWWE outfalls, similarity in habitat, and wadeability. Habitat analysis indicated that there were no large physical differences among sites. Fish communities were collected in a standardized method with a backpack electroshocker at each site (six randomly selected 10 m by 10 m sub-sites for 5 min). Greenside Darter (Etheostoma blennioides) and Rainbow Darter (E. caeruleum), the most abundant species, were also analyzed for stable isotope signatures (δ13C and δ15N) at each site. Downstream of the Guelph outfall there were no changes in mean total catch per unit effort (CPUE) or mean total mass. Changes to diversity, resilience, and tolerance in the fish community were attributed to a decreased abundance of Greenside Darter and increased abundance of Rainbow Darter. Downstream of the Kitchener discharge, there was a trend towards decreasing mean total CPUE, especially for darter species, and an increase in mean total mass due to a community shift to larger species including Catostomids and Centrarchids. The changes in abundance of Rainbow Darter, Catostomids, and Centrarchids among reference and Kitchener MWWE exposed sites explained the pattern in resilience, tolerance, and diet classifications. Lower diversity downstream of all three MWWE outfalls can be attributed to the increase in Rainbow Darter abundance. Stable isotope signatures (δ13C and δ15N) of Greenside Darter did not change downstream of the Guelph and Waterloo discharges, but signatures of Rainbow Darter increased immediately below the two outfalls. This shift may be due to the Rainbow Darter being able to take advantage of a change in the environment (i.e. food availability), resulting in its increased abundance and changes in isotopic signature. Directly downstream of the Kitchener outfall both darter species had an increase in δ13C and a large decrease in δ15N, likely due to high nutrient inputs from the outfall. The Kitchener wastewater discharge is also associated with a decrease in abundance of fish and a shift in community structure. MWWEs are currently affecting the aquatic environment, including fish communities in the Grand River watershed. Future investments in infrastructure and watershed management should be made to mitigate degradation of water quality in this watershed.

Fast paced population growth in urban areas of southern Ontario is putting increased pressure on the surrounding aquatic environment. The City of Guelph uses the Speed River to assimilate its municipal wastewater effluent. With a projected 57% population increase in the watershed by 2031, the assimilative capacity of the river may be challenged in the coming years. The Guelph Wastewater Treatment Plant uses tertiary treatment methods greatly reducing ammonia, suspended solids and phosphate concentrations in the effluent. However there are still impacts detectable related to excessive nutrients released into this relatively small river (6th order) which promotes algae and aquatic macrophyte growth. There is also concern about a variety of emerging contaminants that may enter the river and impact the health of the ecosystem. The research in this thesis examined the seasonal and spatial variability and extent of the impacts of the wastewater effluent on the riffle fish communities in the Speed River. Stable isotope signatures (δ13C and δ15N) were used to understand the changes in the dominant benthic fish species, Rainbow Darters (Etheostoma caeruleum) and Greenside Darters (E. blennioides), relative to changes in invertebrate signatures and their abundance. Rainbow Darters were extremely abundant relative to Greenside Darters at the site immediately downstream of the effluent outfall, particularly in August. The benthic invertebrate community was distinctly different downstream of the effluent outfall, especially in the summer, with a reduced abundance of Elmidae beetle larvae and increased abundance of isopods (Caecidotea intermedius) compared to upstream. δ13C and δ15N of the two darters species were similar at all sites in May and July, but in August and October Rainbow Darter signatures were more enriched in the two heavier isotopes at sites downstream of the effluent outfall. The vast majority of invertebrate taxa sampled were also enriched at the downstream sites. An analysis of Rainbow and Greenside Darter stomach contents revealed that Rainbow Darters incorporated more isopods and other invertebrates in their diet, especially at the immediate downstream sites suggesting that they are more adaptable to the altered downstream environment. The feeding habits of Greenside Darters appear to change between July and August in response to changes in habitat and food availability. They are potentially consuming food organisms with less enriched isotopic signatures, which results in their isotopic signatures not rising during these months like most of the invertebrates and other fish. Alternatively, the Greenside Darters may move across the stream to feed on invertebrates that remain unexposed to the wastewater effluent. These impacts, although subtle, may be a reflection of the Speed River ecosystem being compromised by nutrient inputs from the wastewater effluent. With the impending increase in demand on the treatment plant (e.g., population growth), ongoing treatment and infrastructure improvements may be needed in the future to maintain the current ecosystem structure.

Fast paced population growth in urban areas of southern Ontario is putting increased pressure on the surrounding aquatic environment. The City of Guelph uses the Speed River to assimilate its municipal wastewater effluent. With a projected 57% population increase in the watershed by 2031, the assimilative capacity of the river may be challenged in the coming years. The Guelph Wastewater Treatment Plant uses tertiary treatment methods greatly reducing ammonia, suspended solids and phosphate concentrations in the effluent. However there are still impacts detectable related to excessive nutrients released into this relatively small river (6th order) which promotes algae and aquatic macrophyte growth. There is also concern about a variety of emerging contaminants that may enter the river and impact the health of the ecosystem. The research in this thesis examined the seasonal and spatial variability and extent of the impacts of the wastewater effluent on the riffle fish communities in the Speed River. Stable isotope signatures (δ13C and δ15N) were used to understand the changes in the dominant benthic fish species, Rainbow Darters (Etheostoma caeruleum) and Greenside Darters (E. blennioides), relative to changes in invertebrate signatures and their abundance. Rainbow Darters were extremely abundant relative to Greenside Darters at the site immediately downstream of the effluent outfall, particularly in August. The benthic invertebrate community was distinctly different downstream of the effluent outfall, especially in the summer, with a reduced abundance of Elmidae beetle larvae and increased abundance of isopods (Caecidotea intermedius) compared to upstream. δ13C and δ15N of the two darters species were similar at all sites in May and July, but in August and October Rainbow Darter signatures were more enriched in the two heavier isotopes at sites downstream of the effluent outfall. The vast majority of invertebrate taxa sampled were also enriched at the downstream sites. An analysis of Rainbow and Greenside Darter stomach contents revealed that Rainbow Darters incorporated more isopods and other invertebrates in their diet, especially at the immediate downstream sites suggesting that they are more adaptable to the altered downstream environment. The feeding habits of Greenside Darters appear to change between July and August in response to changes in habitat and food availability. They are potentially consuming food organisms with less enriched isotopic signatures, which results in their isotopic signatures not rising during these months like most of the invertebrates and other fish. Alternatively, the Greenside Darters may move across the stream to feed on invertebrates that remain unexposed to the wastewater effluent. These impacts, although subtle, may be a reflection of the Speed River ecosystem being compromised by nutrient inputs from the wastewater effluent. With the impending increase in demand on the treatment plant (e.g., population growth), ongoing treatment and infrastructure improvements may be needed in the future to maintain the current ecosystem structure.