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Full-Text Articles in Aquaculture and Fisheries

The Economic And Social Values Associated With Small South Dakota Lakes, Aaron Patrick Sundmark Jan 2019

The Economic And Social Values Associated With Small South Dakota Lakes, Aaron Patrick Sundmark

Electronic Theses and Dissertations

The valuation of small fishing lakes is a vital component in understanding the importance of fishing and of recreational resources, in general. Knowing the values associated with such lakes is essential when prioritizing management activities. The overall value of a lake as a resource for human benefit is estimated as the summation of both instrumental and non-instrumental values. Instrumental values consist of economic and utilitarian values, as well as the values that a lake provides from ecosystem services. Non-instrumental values consider what the lake is worth as a good of its own, such as aesthetic, moral, and spiritual values gained …


Assessing Freshwater Mussel (Bivalvia: Unionidae) Assemblages And Effects Of Eutrophication On Pyganodon Grandis In Lakes Of Eastern South Dakota, Katherine M. Wollman Jan 2019

Assessing Freshwater Mussel (Bivalvia: Unionidae) Assemblages And Effects Of Eutrophication On Pyganodon Grandis In Lakes Of Eastern South Dakota, Katherine M. Wollman

Electronic Theses and Dissertations

Globally, the family Unionidae is the most threatened group of freshwater fauna. South Dakota is well known for its agricultural production, leading to cultural eutrophication from enhanced fertilizers and sediments. This impact can alter species presence, age, growth and mortality. Objectives of this study were to 1) implement the first comprehensive lake survey of freshwater mussels in eastern South Dakota lakes and document distribution, occurrence and relative abundance, 2) evaluate relationships between age, growth and mortality of Pyganodon grandis and lake trophic state. Freshwater mussels were sampled in 2017 from 116 proportionally and randomly selected natural lakes and reservoir basins …


Social Conflict On The Seas: Links Between Overfishing-Induced Marine Fish Stock Declines And Forced Labor Slavery, Jessica L. Sparks Jan 2018

Social Conflict On The Seas: Links Between Overfishing-Induced Marine Fish Stock Declines And Forced Labor Slavery, Jessica L. Sparks

Electronic Theses and Dissertations

Despite media attention detailing labor abuses in fisheries, social-ecological systems research has largely failed to consider whether fish stock declines could be contributing to increases in forced labor slavery. Empirical fisheries data suggests, though not a ubiquitous response to declining stocks, many vessels will fish longer, farther from shore, and deeper in waters to maintain yields. This effort intensification increases production costs, and Brashares et al. (2014), consistent with slavery theory, posited cheap and/or unpaid labor as an approach to offset increasing costs and continue harvesting fish species at a rate otherwise cost-prohibitive.

Using fuzzy cognitive mapping - a participatory, …


Western Prairie Stream Fisheries: An Assessment Of Past And Present Fish Assemblage Structure, Biotic Homogenization, And Population Dynamics In Western South Dakota Streams, Stephen Jones Jan 2018

Western Prairie Stream Fisheries: An Assessment Of Past And Present Fish Assemblage Structure, Biotic Homogenization, And Population Dynamics In Western South Dakota Streams, Stephen Jones

Electronic Theses and Dissertations

Biodiversity is declining globally, especially in in aquatic systems. Prairies are one of the most endangered ecosystem types in North America, and their conversion into agriculture or development as a result of urbanization has had negative effects on prairie stream fish communities. Continued monitoring of fish assemblage change and the population dynamics of prairie stream fishes will provide researchers and managers with valuable information needed to detect and mitigate past and future negative impacts on prairie stream aquatic ecosystems. Sampling was conducted in the mainstem and tributaries of the Grand, Moreau, Cheyenne, Bad, and White rivers within western South Dakota. …


Impacts On Salmonid Rearing Performance With Use Of Dietary Bioprocessed Plant-Based Protein And Water Velocity, Jill Voorhees Jan 2018

Impacts On Salmonid Rearing Performance With Use Of Dietary Bioprocessed Plant-Based Protein And Water Velocity, Jill Voorhees

Electronic Theses and Dissertations

The inclusion of bioprocessed soybean (Glycine max) meal was evaluated in five experiments using either Rainbow Trout (Oncorhynchus mykiss) or Brown Trout (Salmo trutta). In the first experiment, adult Erwin x Arlee strain Rainbow Trout were fed diets formulated so that bioprocessed soybean meal (BSM) replaced 0, 60, or 80% of the dietary fishmeal. There were no significant differences in gain, percent gain, feed conversion ratio, specific growth rate, intestinal morphology, relative fin lengths, or organosomatic indices. In the second experiment, juvenile Plymouth strain Brown Trout were fed diets formulated so that BSM replaced 0, 60, 80, or 100% of …


Effects Of Large-Scale Density Reduction On Brown Trout Growth And Movement In Spearfish Creek, South Dakota, Travis Rehm Jan 2018

Effects Of Large-Scale Density Reduction On Brown Trout Growth And Movement In Spearfish Creek, South Dakota, Travis Rehm

Electronic Theses and Dissertations

Density-dependent growth is often observed in stream-dwelling Brown Trout Salmo trutta populations. In Spearfish Creek, South Dakota, biomass of adult Brown Trout (>200 mm) is about three times greater than that reported for similar Black Hills streams while mean length of adult fish is about 30% less. Here, we evaluate large-scale density reduction as a management tool for improving growth rate of stream-dwelling Brown Trout. We compared age-specific growth of wild Brown Trout in stream sections receiving 50% reductions in fish abundance. We also assessed the effect of fish density manipulation on Brown Trout movement patterns and home range …


Walleye Fishery Ecology In Lake Oahe Of The Dakotas, Eli Felts Jan 2018

Walleye Fishery Ecology In Lake Oahe Of The Dakotas, Eli Felts

Electronic Theses and Dissertations

Walleye Sander vitreus is among the most popular sport fishes in North America and is the most sought-after fish in both South Dakota and North Dakota. Lake Oahe, a large main stem Missouri River reservoir, spans state boundaries and provides one of the most popular and productive Walleye fisheries in both Dakotas. The Walleye population of Lake Oahe has experienced wide fluctuations in abundance and size structure over the last 25 years which has caused high variability in angler use and satisfaction. Much of this variation is thought to be driven by Rainbow Smelt Osmserus mordax, which are the dominant …


Nutritional Value Of Modified Novel Oilseed Meals In Teleost Diets, Tom Kasiga Jan 2018

Nutritional Value Of Modified Novel Oilseed Meals In Teleost Diets, Tom Kasiga

Electronic Theses and Dissertations

Carinata Brassica carinata and camelina Camelina sativa are being genetically modified to improve their composition for biofuel production and other agricultural applications. After oil extraction, the residual de-oiled meals (40%) in protein. However, their inclusion in animal feeds is limited to 10% because of high levels of antinutritional factors (ANFs), mainly glucosinolates (GLS), sinapine, and crude fiber that limit diet intake, nutrient utilization, and lower thyroxine production, resulting in reduced growth. The nutritional value of carinata and camelina seed meals to fish were assessed by subjecting cold pressed (CP) carinata and camelina meals to extrusion (EX), solvent extraction (SE) and …


Habitat Use Of Blacktip Sharks (Carcharhinus Limbatus) At Fishing Piers, Kelsey L. Spencer Dec 2017

Habitat Use Of Blacktip Sharks (Carcharhinus Limbatus) At Fishing Piers, Kelsey L. Spencer

Electronic Theses and Dissertations

Blacktip sharks (Carcharhinus limbatus) can be observed near fishing piers throughout the summer along the northeast coast of South Carolina. These piers attract and support a wide variety of potential prey and sharks are able to forage on fishers’ discards with minimal energetic cost. I tagged 12 blacktip sharks with acoustic transmitters, monitored piers with acoustic receivers, and conducted pier-creel surveys to determine the habitat use of blacktip sharks at fishing piers, factors that influenced residence time and presence/absence at piers, and any cyclical patterns in visits to piers. Data were analyzed with pier association indices (PAI), mixed models, and …


Invertebrate Prey Selectivity Of Channel Catfish (Ictalurus Punctatus) In Western South Dakota Prairie Streams, Erin D. Peterson Jan 2017

Invertebrate Prey Selectivity Of Channel Catfish (Ictalurus Punctatus) In Western South Dakota Prairie Streams, Erin D. Peterson

Electronic Theses and Dissertations

Benthic invertebrates are an important resource for aquatic consumers and should be considered in management of sportfish populations as a factor influencing fishery health. Our study seeks to draw a relationship between invertebrate prey availability and the Channel Catfish Ictalurus punctatus fishery of western South Dakota through diet analysis, but invertebrate surveys in the area have not focused on invertebrates as a prey source. Our objectives were to characterize patterns in availability of the invertebrate prey base in five major river basins, and to evaluate the effects of availability on Channel Catfish prey selectivity and condition. Invertebrates were collected at …


Indexing Walleye Recruitment In Eastern South Dakota Natural Lakes, Todd M. Kaufman Jan 2017

Indexing Walleye Recruitment In Eastern South Dakota Natural Lakes, Todd M. Kaufman

Electronic Theses and Dissertations

Because of the popularity of Walleyes and the need for recurrent supplemental stockings, substantial resources are allocated to their management in eastern South Dakota. For nearly 20 years, fall night electrofishing has been used to monitor age-0 Walleye population parameters, and index future year-class strength in select waters but with limited evaluation. Additionally, knowledge of recruitment patterns and factors that influence those patterns were of interest. Thus, the objectives of this study were: 1) to determine the utility of fall electrofishing age-0 Walleyes to index future year-class strength; 2) to explore whether measures of fall age-0 body size or condition …


Growth Potential And Genetic Diversity Of Yellow Perch In South Dakota, Alex J. Rosburg Jan 2017

Growth Potential And Genetic Diversity Of Yellow Perch In South Dakota, Alex J. Rosburg

Electronic Theses and Dissertations

Yellow Perch Perca flavescens represent a valued sport fish throughout their range and are an important prey species for piscivorous fishes. In South Dakota, two distinct population types of Yellow Perch have been characterized that differ in growth, survival, and recruitment patterns. Fast growth populations exhibit high growth rates, high mortality, low population density, and inconsistent recruitment. In contrast, slow growth populations are characterized by reduced growth rates, low mortality, high population density, and relatively consistent recruitment. The role of genetics in contributing to these population characteristics is currently unknown. To address these questions, I used high-throughput restriction-site associated DNA …


Go With The Flow: Patterns Of Connectivity In Low Dispersal Coral Reef Gobies (Coryphopterus Spp.) Throughout The Western Atlantic, Daniel Volk Jan 2017

Go With The Flow: Patterns Of Connectivity In Low Dispersal Coral Reef Gobies (Coryphopterus Spp.) Throughout The Western Atlantic, Daniel Volk

Electronic Theses and Dissertations

Gene flow is an integral biological process that can mediate speciation. While many consider the ocean to be an open environment, there are many barriers that limit gene flow, particularly in the western Atlantic. I analyzed data from two widespread, coral reef fishes, the bridled goby (Coryphopterus glaucofraenum) and sand-canyon goby (C. venezuelae), throughout their range in the western Atlantic. Using two genetic datasets, mitochondrial DNA (mtDNA) and genomic SNPs, I investigated the evolutionary history of these species and inferred the location and strength of putative barriers. My results suggest that several unique lineages have genetically diverged from one another …


Development And Application Of A Fish-Based Index Of Biotic Integrity For Lakes In Eastern South Dakota, Daniel T. Nelson Jan 2017

Development And Application Of A Fish-Based Index Of Biotic Integrity For Lakes In Eastern South Dakota, Daniel T. Nelson

Electronic Theses and Dissertations

The Index of Biotic Integrity (IBI) was developed to summarize the impact of watershed and water quality degradation to biotic communities and help to provide a more complete picture of water quality changes that are not captured in traditional physical and chemical measurements. In 2014, nearly 15% of South Dakota lakes did not meet their designated beneficial uses based on water quality measures but the impacts to the fish communities are unknown. The goal of this study was to develop a fish-based IBI for eastern South Dakota lakes by addressing three specific objectives:
1) Determine whether an IBI could be …


Measuring Aquatic Organism Responses To Grassland Restoration: Does The Field Of Dreams Really Exist?, David A. Schumann Jan 2017

Measuring Aquatic Organism Responses To Grassland Restoration: Does The Field Of Dreams Really Exist?, David A. Schumann

Electronic Theses and Dissertations

Landscape homogenization and the degradation of riparian areas has greatly impaired stream ecosystems throughout North America. Conservation programs may repair riparian ecosystems to indirectly improve water quality and instream habitat heterogeneity in hopes to elicit biological responses. However, focused manipulations on isolated stream fragments have rarely achieved biological goals. Prairie streams with restored riparian areas were appraised (chemical, physical, and biological variables) to quantify the indirect effects of prevalent grassland conservation practices on aquatic resources. Riparian rehabilitation, via passive methods, promoted bank-stabilizing vegetation along all conservation stream reaches. Riparian vegetation and function quickly recovered from previous agricultural disturbances at conservation …


Effects Of A Large-Scale Habitat Enhancement Project On Largemouth Bass Behavior, Feeding, And Growth In Grand Lake, Texas, Chance Kirkeeng Jan 2017

Effects Of A Large-Scale Habitat Enhancement Project On Largemouth Bass Behavior, Feeding, And Growth In Grand Lake, Texas, Chance Kirkeeng

Electronic Theses and Dissertations

The quality of habitat, or the environment suitable for an organism to survive and reproduce, is often described by the type of features present and the quantity and condition of such features. Habitats in many ecosystems are declining and the loss of important habitats likely affects the success of organisms reliant upon those features. Habitats in reservoir ecosystems are especially at risk because of aging processes that are degrading reservoir habitats at faster rates than habitats in other ecosystems. Habitat enhancement projects are one tool used to combat the effects of aging reservoirs but the benefits of these management actions …


An Evaluation Of Nitrogen Supplementation And Processed Soy Fractions On The Performance Of Cultured Fishes, Brandon M. White Jan 2017

An Evaluation Of Nitrogen Supplementation And Processed Soy Fractions On The Performance Of Cultured Fishes, Brandon M. White

Electronic Theses and Dissertations

World population growth has resulted in an increased demand for a sustainable food supply. This rapid growth coupled with an increased per capita consumption of seafood, has resulted in many of the world’s marine fisheries being over-exploited in an effort to meet the global demand for seafood. Aquaculture has attempted to fill the supply and demand gap created by the dwindling supply of fish in the world’s oceans. Fishmeal (FM) has traditionally been the primary protein ingredient in aquafeeds fed to farm-raised fish, however its unstable supply and increasing price have driven researchers to identify alternative protein sources. Soybean meal …


Ecology Of Largemouth Bass In An Aging Reservoir: Implications For Creating A Trophy Largemouth Bass Fishery, Jason Breeggemann Jan 2016

Ecology Of Largemouth Bass In An Aging Reservoir: Implications For Creating A Trophy Largemouth Bass Fishery, Jason Breeggemann

Electronic Theses and Dissertations

There are an estimated 3-9 million small reservoirs and nearly 1,000 large reservoirs in the United States. Most of these reservoirs were built several decades ago and are experiencing symptoms of reservoir aging, including loss of habitat, sedimentation, and decreased fishery production. Furthermore, over the last several decades, there has been an increasing interest among anglers for high quality, trophy fisheries. However, little is known about exactly how the reservoir aging process affects the ecology and especially growth potential of Largemouth Bass, particularly under potential climate change scenarios. Grand Lake in TX is a 45ha ageing reservoir that was built …


Immune And Endocrine Modulations Associated With Enhanced Plant-Based Protein Diets Within Freshwater Fish Species, Timothy J. Bruce Jan 2016

Immune And Endocrine Modulations Associated With Enhanced Plant-Based Protein Diets Within Freshwater Fish Species, Timothy J. Bruce

Electronic Theses and Dissertations

The incorporation of bioprocessed soybean meals (BSBMs) as a protein replacement for marine-derived fish meal (MDFM) has gained momentum with the potential for aquafeed cost reduction, improved growth performance, and reducing exploitation on wild fish stocks. Further, potential health benefits and optimized production performance resulting from bioprocessed feed ingredients have led to research on the nutraceutical benefits of plant-based ingredients. A novel proprietary MBBM has been developed using a microbial conversion of carbohydrates into digestible protein and additional cellular components that have immunogenic potential. A series of five finfish feeding trials were conducted to investigate immunomodulation induced by the BSBM …


The Contribution Of Missouri River Reservoir Side-Channel And Floodplain Habitats To Mainstem Fish Populations: The Effects Of Losing Connectivity Between Hipple Lake And Lake Sharpe, William Joseph Radigan Jan 2016

The Contribution Of Missouri River Reservoir Side-Channel And Floodplain Habitats To Mainstem Fish Populations: The Effects Of Losing Connectivity Between Hipple Lake And Lake Sharpe, William Joseph Radigan

Electronic Theses and Dissertations

Catastrophic flooding of the Missouri River in 2011 has had lasting effects on floodplain habitats (i.e. floodplain lakes) and side-channel habitats (e.g. canals, side-channel embayments, stilling basins, and tributaries) in Lake Sharpe, SD. Floodplain and side-channel habitats are rare habitat in Lake Sharpe, a mainstem Missouri River reservoir, and are thought to be crucial habitat for prey and sport fish. Hipple Lake, the only warm-water floodplain embayment in Lake Sharpe, is in danger of losing connectivity to the reservoir because of sedimentation resulting from the 2011 flood. To evaluate Hipple Lake’s natal and adult contribution to Lake Sharpe’s fishery, otolith …


Assessing Freshwater Mussels (Bivalvia: Unionidae) In South Dakota And Identifying Drivers Of Assemblage Variation, Kaylee L. Faltys Jan 2016

Assessing Freshwater Mussels (Bivalvia: Unionidae) In South Dakota And Identifying Drivers Of Assemblage Variation, Kaylee L. Faltys

Electronic Theses and Dissertations

Native freshwater mussels (Family: Unionidae) are among the most threatened groups of freshwater fauna on Earth. Approximately 35 species have gone extinct since the 1900s and 72% of remaining species are considered endangered, threatened, or species of special concern. Unionid research can begin by establishing species presence and distributions via surveys. Objectives for this study were to 1) implement the first comprehensive unionid survey for South Dakota to assess distribution, composition, and decline, 2) estimate assemblage density and determine local versus broad scale habitat drivers of assemblage variation, and 3) determine areas of unionid conservation priority in South Dakota. Mussels …


Fish Ladders Designed For Drop Culverts And Central Stoneroller Ecology Across A Latitudinal Gradient, John Arthur Lorenzen Jan 2016

Fish Ladders Designed For Drop Culverts And Central Stoneroller Ecology Across A Latitudinal Gradient, John Arthur Lorenzen

Electronic Theses and Dissertations

Stream connectivity is essential for the persistence of fish populations and maintenance of fish assemblage structure. Stream-road crossings can become barriers resulting in a loss of connectivity. Creating innovative tools for fisheries managers to allow fish passage through barrier stream-road crossings is important worldwide as climate change may force range shifts to stay within thermal requirements. Understanding how populations and metapopulations respond to climate is important as fisheries managers can use this information to make informed management decisions in regards to climate change and possible range shifts. Thus, we developed and tested a fish ladder to retrofit barrier stream-road crossings …


Survival, Abundance, And Relative Predation Of Wild Rainbow Trout In The Deerfield Reservoir System, South Dakota, Jeremy L. Kientz Jan 2016

Survival, Abundance, And Relative Predation Of Wild Rainbow Trout In The Deerfield Reservoir System, South Dakota, Jeremy L. Kientz

Electronic Theses and Dissertations

Rainbow Trout Oncorhynchus mykiss are routinely stocked in Black Hills streams and reservoirs to enhance angling opportunities for the public, however in most cases, hatchery-reared Rainbow Trout do not successfully recruit to establish natural populations. One exception is the Deerfield Reservoir system, where it is estimated that up to 25% of the Rainbow Trout population consists of naturally produced, wild Rainbow Trout. While recruitment of wild Rainbow Trout to the Deerfield Reservoir fishery does occur, annual stockings of 12,000 hatchery Rainbow Trout have continued. In recent years, adipose fin clips were used to identify hatchery Rainbow Trout stocked into Deerfield …


A Physiological Assessment Of Wetland Habitats For Spring-Migrating Ducks In The Agricultural Landscapes Of The Southern Prairie Pothole Region, Adam K. Janke Jan 2016

A Physiological Assessment Of Wetland Habitats For Spring-Migrating Ducks In The Agricultural Landscapes Of The Southern Prairie Pothole Region, Adam K. Janke

Electronic Theses and Dissertations

The conversion of grassland and wetland ecosystems in the Prairie Pothole Region (PPR) has been a pervasive challenge for conservationists dating back to the early 1900s. The legacy of ever-increasing agricultural intensity in the southern portions of the PPR, including eastern South Dakota, has left many wetland ecosystems in a matrix of intensive agricultural production. With little surrounding nesting cover, these wetlands are thought to have limited potential for waterfowl reproduction but may still play an important role facilitating migration of waterfowl en route to northern breeding areas during spring. My research sought to understand the contributions of wetlands in …


A Comparison Between South Dakota And North American Standard Sampling Gears In Lakes And Reservoirs, Bradley J. Smith Jan 2015

A Comparison Between South Dakota And North American Standard Sampling Gears In Lakes And Reservoirs, Bradley J. Smith

Electronic Theses and Dissertations

A statewide gear comparison was performed in South Dakota during 2013 and 2014 between current South Dakota Department of Game, Fish and Parks (SDGFP) sampling gears (i.e., gill nets and modified fyke nets) and their equivalents described in Standard Methods for Sampling North American Freshwater Fishes (Standard). Adopting Standard gears would provide uniform gear specifications for annual sampling statewide, facilitate data sharing within South Dakota and beyond, and allow for large-scale spatial and temporal analyses relevant to researchers and managers. Sampling was divided between non-Missouri River (non-MR) and Missouri River (MR) systems because gill nets used by SDGFP to sample …


The Effects Of Chanellization And Channel Restoration On Aquatic Habitat And Biota Of The Pecos River, New Mexico, Darrel J. Mecham Jan 2015

The Effects Of Chanellization And Channel Restoration On Aquatic Habitat And Biota Of The Pecos River, New Mexico, Darrel J. Mecham

Electronic Theses and Dissertations

River channelization has been shown to negatively impact riverine ecosystems by degrading aquatic habitat conditions, decreasing diversity of both fish and aquatic invertebrate assemblages and impairing fish recruitment. As knowledge of the negative impacts of channelization has increased, so have channel restoration efforts. We evaluated a recent channel restoration project on the Pecos River, New Mexico by comparing abiotic and biotic conditions among five reaches of river, including the restored reach, an unchannelized reach and a channelized reach all prone to streamflow intermittence and an unchannelized reach and channelized reach more perennial in nature. Our first objective was to assess …


The Reproductive Ecology Of Two Sympatric Demersal Fishes: The Naked Goby Gobiosoma Bosc And Striped Blenny Chasmodes Bosquianus, Rachel M. Tremont Jan 2014

The Reproductive Ecology Of Two Sympatric Demersal Fishes: The Naked Goby Gobiosoma Bosc And Striped Blenny Chasmodes Bosquianus, Rachel M. Tremont

Electronic Theses and Dissertations

The naked goby (Gobiosoma bosc) and striped blenny (Chasmodes bosquianus) are sympatric oyster reef fishes within temperate estuaries. The reproductive biology and early life history of these fishes were described during two consecutive spawning seasons from 2012-2013 in North Inlet, SC. The naked goby and striped blenny spawning seasons lasted for 21 weeks and 30 weeks, respectively, for 2012 and 2013. The naked goby spawning season began 3 weeks later than the striped blenny spawning season for both years. The temporal offset in the start of their spawning seasons may reduce competition for nest habitat between the two species. Naked …


Historical Catch Trends And Efficacy Of Video Surveillance Monitoring Of Catch Per Unit Effort At Recreational Fishing Piers In South Carolina, Charles Christian Johnson Jan 2013

Historical Catch Trends And Efficacy Of Video Surveillance Monitoring Of Catch Per Unit Effort At Recreational Fishing Piers In South Carolina, Charles Christian Johnson

Electronic Theses and Dissertations

In recent years, recreational anglers claim declining catch rates in the shore-based pier fishery in South Carolina. The study seeks to evaluate whether catch data supports angler testimony in this region, to examine the relationship of landings at piers in context of the regional level, and to test a method which would enhance the ability of managers to monitor landings of this under-studied fishery. Novel, non-standardized catch series extending back to 1973 were acquired from fishing piers and examined in an attempt to produce significant trends in measures of catch. King mackerel catch (Scomberomorus cavalla) was tested for correlation to …


Ecology Of Glacial Relict Fishes In South Dakota's Sandhills Region, Eli Felts Jan 2013

Ecology Of Glacial Relict Fishes In South Dakota's Sandhills Region, Eli Felts

Electronic Theses and Dissertations

Native stream fish zoogeography has changed substantially across North America during the last century as habitat degradation, stream fragmentation and introductions of nonnative species have led to numerous extinctions, extirpations and altered distributions. Insufficient information regarding imperiled species often results in reactive, rather than proactive, management, and knowledge of species status and ecology is critical in identifying conservation priorities. South Dakota populations of three dace species (northern redbelly dace Chrosomus eos, finescale dace Chrosomus neogaeus, and pearl dace Margariscus margarita) are relict of Pleistocene Glaciation and are isolated from the northern core of their distribution, but little information exists regarding …


Use Of High Pressure Liquid Chromatography To Detect And Quantify Oxytetracycline Marks In Walleye Otoliths And Dorsal Spines, Michael J. Hawkins Jan 2002

Use Of High Pressure Liquid Chromatography To Detect And Quantify Oxytetracycline Marks In Walleye Otoliths And Dorsal Spines, Michael J. Hawkins

Electronic Theses and Dissertations

Oxytetracycline (OTC) is used to chemically mark calcified structures in walleye Stizostedion vitreum fry and fingerlings. Current visual methods for detection of these marks are subjective, and biologists are unable to quantify the amount of OTC in a sample. The goal of this study was to determine if high pressure liquid chromatography (HPLC) is a feasible and superior alternative for detecting and quantifying OTC in otoliths of fry-marked and spines of fingerlingmarked walleyes. Study objectives were to validate methodology of extraction of OTC from calcified tissue, detect and quantify extracted OTC using HPLC, and determine a cost comparison of current …