Open Access. Powered by Scholars. Published by Universities.®

Aquaculture and Fisheries Commons™

Open Access. Powered by Scholars. Published by Universities.®

2014

Discipline
Institution
Keyword
Publication
Publication Type

Articles 31 - 60 of 155

Full-Text Articles in Aquaculture and Fisheries

Predictors Patterns And Processes Of Extinction Risk In Porgies And Seabreams (Family: Sparidae), Mia Theresa B. Conteros Oct 2014

Predictors Patterns And Processes Of Extinction Risk In Porgies And Seabreams (Family: Sparidae), Mia Theresa B. Conteros

Biological Sciences Theses & Dissertations

A variety of human-induced changes are having profound impacts on the marine environment, and no area on the planet remains unaffected by the detrimental effects of our activities. These stressors can potentially lead to synergistic effects, causing accelerated biodiversity loss and diminished ecosystem functioning. Identification and understanding of the factors that drive species to heightened risk of extinction are important goals in conservation.

The Sparidae are commercially important and ecologically complex marine fishes; global extinction risk assessments using the IUCN Red List of Threatened Species methodology show that 9% (13 species) have increased vulnerability to population declines from intense fishing …


Schooling Increases Risk Exposure For Fish Navigating Past Artificial Barriers, Bertrand H. Lemasson, James W. Haefner, Mark D. Bowen Sep 2014

Schooling Increases Risk Exposure For Fish Navigating Past Artificial Barriers, Bertrand H. Lemasson, James W. Haefner, Mark D. Bowen

Biology Faculty Publications

Artificial barriers have become ubiquitous features in freshwater ecosystems and they can significantly impact a region's biodiversity. Assessing the risk faced by fish forced to navigate their way around artificial barriers is largely based on assays of individual swimming behavior. However, social interactions can significantly influence fish movement patterns and alter their risk exposure. Using an experimental flume, we assessed the effects of social interactions on the amount of time required for juvenile palmetto bass (Morone chrysops × M. saxatilis) to navigate downstream past an artificial barrier. Fish were released either individually or in groups into the flume …


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 …


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 …


Effect Of Increased Water Temperature On Warm Water Fish Feeding Behavior And Habitat Use, Eric Walberg Aug 2014

Effect Of Increased Water Temperature On Warm Water Fish Feeding Behavior And Habitat Use, Eric Walberg

Journal of Undergraduate Research at Minnesota State University, Mankato

Global warming could cause changes in species behavior and life history. Stream fish may be significantly affected by climate change because individuals are restricted in their movements by water systems and other physical factors, preventing migration to locations more thermally suitable. The effect of warmer waters on stream fish could change behavior and affect the fish species survival and ultimately ecosystem function. During my experiment I observed the effects of increased water temperature on the feeding behavior and habitat use of two native Minnesota fish species, black crappie (Pomoxis nigromaculatus) and black bullhead (Ameiurus melas). An increase of 2oC over …


Anti-Predator Responses Of Fathead Minnows To Alarm Substance Pheromone, Sarah Thomson Aug 2014

Anti-Predator Responses Of Fathead Minnows To Alarm Substance Pheromone, Sarah Thomson

Journal of Undergraduate Research at Minnesota State University, Mankato

In some fish, alarm substances are released from skin cells when they are bitten by a predator, signaling nearby fish in potential danger. Such anti-predator defenses have been studied in the fathead minnow (Pimephales promelas), and some have hypothesized that the response to the alarm substance is not instinctual, but rather fish must learn to associate it with a predation cue such as motion. The purpose of this study is to detect an effect of conditioning (associating alarm substance with predation threat) on minnow responses to alarm substance. We tested the prediction that conditioned fish would react more strongly to …


Atrazine Influence On Northern Pike Sperm Motility And Viability In Minnesota, Andy Stevens, Paul Pallardy Aug 2014

Atrazine Influence On Northern Pike Sperm Motility And Viability In Minnesota, Andy Stevens, Paul Pallardy

Journal of Undergraduate Research at Minnesota State University, Mankato

Concern has been noted by fish hatchery biologists with the Department of Natural Resources that southern Minnesota northern pike Esox lucius populations have exhibited reduced hatching rates, a trend not occurring with northern Minnesota pike populations. The chemical atrazine is a frequently used herbicide in Minnesota and has been found to cause gonadal dysgenesis and reproductive development issues in amphibians and fish. Sperm, length, and age data were collected from northern pike in four Minnesota lakes. Water samples were obtained from two of the lakes to test for atrazine. Test results indicated atrazine concentrations0.10 and r2 < 0.06 for all regressions). Sperm motility reductions in northern pike could be related to declining populations and warrants further research.


Assessment Of Salmon Habitat On The Feather River, Nathan Sweem Aug 2014

Assessment Of Salmon Habitat On The Feather River, Nathan Sweem

STAR Program Research Presentations

Human activity in central valley streams has had a significantly negative impact on salmon habitat (Williams 2006). The presence of dams impedes sediment transport which is critical to salmon spawning (Williams 2006; Kondolf 1997). As part of an effort to enhance salmon spawning, the California Department of Water Resources added 7000 ft3 of gravel to Cottonwood Hatchery, Upper Auditorium, and Auditorium riffles on the Lower Feather River below the Thermalito Dam Complex in July of 2014. Stream conditions at Cottonwood Hatchery riffle were assessed by conducting analysis of sediment grain size, water depth and velocity, gravel permeability, and dissolved …


Aquaponics And Basil Plant Density, Danika L. Macmaster, Brook Murphy, Dudley Burton Aug 2014

Aquaponics And Basil Plant Density, Danika L. Macmaster, Brook Murphy, Dudley Burton

STAR Program Research Presentations

Aquaponics is the use of water from a fish tank to provide nutrients to plants in a soil-less environment. The rocks cultivate the bacteria that turns the ammonia into nitrates that the plants need, and the plant bed functions as a filter for the fish tank. In this study, with the guidance of Doctor Dudley Burton, Doctor Brook Murphy, we researched the optimal plant density for basil in an Aquaponics system. We attempted to control or measure all the other variables to consider, as to isolate the variable of distance between plants. The water flow was spread through the plant …


Decision-Support Tools For Economic Optimization Of Western Rock Lobster Fishery, Nick Caputi, Simon De Lestang, Chris Reid, Sybrand A. Hesp, Jason How, Peter Stephenson Aug 2014

Decision-Support Tools For Economic Optimization Of Western Rock Lobster Fishery, Nick Caputi, Simon De Lestang, Chris Reid, Sybrand A. Hesp, Jason How, Peter Stephenson

Fisheries Research Reports

Objectives: 1. To estimate the annual catch and effort to achieve optimum economic yield 2. To evaluate intra-annual market-based management strategies. 3. To evaluate the economic effect of current and proposed management changes.


Application Of A Bioenergetics Framework For Assessing Sub-Lethal Effects Of Pollutants In The Freshwater Mussel Elliptio Complanata, Christopher G. Goodchild Aug 2014

Application Of A Bioenergetics Framework For Assessing Sub-Lethal Effects Of Pollutants In The Freshwater Mussel Elliptio Complanata, Christopher G. Goodchild

All Theses And Dissertations

Although biomarkers are frequently used to assess sublethal effects of contaminants, a lack of mechanistic linkages to higher-level effects limits the predictive power of biomarkers. Bioenergetics has been proposed as a framework for linking cellular effects to whole-animal effects. We investigated sublethal effects of exposure to wastewater treatment facility effluent in freshwater mussels in situ, thereby capturing ecologically relevant exposure conditions. Our study focused on the energetic biomarker AMP-activated protein kinase (AMPK), while also considering more traditional biomarkers like heat shock proteins (HSP70), and antioxidant enzymes (i.e., superoxide dismutase (SOD), glutathione-S-transferase (GST)). We examined biomarkers at mRNA and protein levels. …


South Atlantic Stream Fish Assemblages: Multi-Scale Structuring Factors, Trait Associations And Channelization, And Responses To Dam Removal, Cathy Marion Aug 2014

South Atlantic Stream Fish Assemblages: Multi-Scale Structuring Factors, Trait Associations And Channelization, And Responses To Dam Removal, Cathy Marion

All Dissertations

South Atlantic coastal plain wadeable streams are unique and understudied freshwater environments that provide crucial habitats for a wide range of aquatic taxa. In Chapter 1, we investigated patterns in fish assemblages across South Carolina's coastal plain, and developed statistical models to identify the dominant multi-scale abiotic environmental factors that influence assemblage structure. Our analyses indicated the presence of four predominant fish assemblages that commonly occur in the coastal plain, which we termed the: 1) fluvial, 2) eastern mudminnow, 3) centrarchid, and 4) non-fluvial assemblages. Natural geographic gradients and instream habitat parameters associated with velocity, channel form, stream size, and …


Ontogenetic Diet Shifts And Prey Preference Of A Generalist Predatory Fish, Brittany Jalene Scharf Jul 2014

Ontogenetic Diet Shifts And Prey Preference Of A Generalist Predatory Fish, Brittany Jalene Scharf

USF Tampa Graduate Theses and Dissertations

Marine ecosystems are highly dynamic and contain a diverse faunal assemblage that are subject to various natural and anthropogenic variability. Globally, seagrass ecosystems are located adjacent to coastal areas that are heavily impacted by human development and urbanization potentially altering the community structure within these ecosystem. Complex food webs connect many components of these systems, often in unexpected ways, and are ultimately based on one of two pathways: benthic (i.e., seagrass, epiphytes, microalgae, detritus) and planktonic (i.e., phytoplankton). Understanding the pathway which the food web is based gives further insight regarding the biological balance of the ecosystem; thus it is …


Informing Flood Plain Wetland Restoration Using Amphibian Monitoring, Ashley Vanderham Jul 2014

Informing Flood Plain Wetland Restoration Using Amphibian Monitoring, Ashley Vanderham

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

Wetlands are among the most important and complex ecosystems in the world. They contribute to nutrient cycling, the hydrologic cycle, and provide critical habitat for many plants, fish, and wildlife. Channelization of Missouri River resulted in the loss of many floodplain wetlands. Despite ongoing restoration efforts, there are few ecologically-based performance guidelines, and managers need methods to quantify and assess the success of restored riverine wetland systems.

In 2008 a multi-institutional herpetofauna monitoring project, funded by the U.S. Army Corps of Engineers, was initiated in four states (Kansas, Missouri, Iowa, and Nebraska). The main goal of the project is to …


Juvenile Green Sturgeon (Acipenser Medirostris) And White Sturgeon (Acipenser Transmontanus) Behavior Near Water-Diversion Fish Screens: Experiments In A Laboratory Swimming Fume, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue Jul 2014

Juvenile Green Sturgeon (Acipenser Medirostris) And White Sturgeon (Acipenser Transmontanus) Behavior Near Water-Diversion Fish Screens: Experiments In A Laboratory Swimming Fume, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue

School of Natural Resources: Faculty Publications

Water diversions that extract fresh water for urban, industrial, and agricultural uses, as well as export to southern California, are prevalent throughout the Sacramento–San Joaquin watershed. Many water diversions are fitted with fish-exclusion screens designed to prevent fish from entrainment (i.e., being drawn in). The impact of fish screens on the behavior of migrating juvenile fishes remains largely unknown, especially for threatened species such as sturgeon. We placed individual juvenile green (Acipenser medirostris) or white (Acipenser transmontanus) sturgeon in a laboratory swimming flume in the presence of standard fish screens (2 mm bar spacing) at two …


Assessing Landscape Constraints On Species Abundance: Does The Neighborhood Limit Species Response To Local Habitat Conservation Programs?, Christopher F. Jorgensen, Larkin A. Powell, Jeffrey J. Lusk, Andrew A. Bishop, Joseph J. Fontaine Jun 2014

Assessing Landscape Constraints On Species Abundance: Does The Neighborhood Limit Species Response To Local Habitat Conservation Programs?, Christopher F. Jorgensen, Larkin A. Powell, Jeffrey J. Lusk, Andrew A. Bishop, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Landscapes in agricultural systems continue to undergo significant change, and the loss of biodiversity is an ever-increasing threat. Although habitat restoration is beneficial, management actions do not always result in the desired outcome. Managers must understand why management actions fail; yet, past studies have focused on assessing habitat attributes at a single spatial scale, and often fail to consider the importance of ecological mechanisms that act across spatial scales. We located survey sites across southern Nebraska, USA and conducted point counts to estimate Ring-necked Pheasant abundance, an economically important species to the region, while simultaneously quantifying landscape effects using a …


Using Otolith Elemental Composition To Track The Habitat Use, Movements, And Life History Patterns Of Common Snook (Centropomus Undecimalis) And Red Drum (Sciaenops Ocellatus) In The Tampa Bay Estuary, Holly Jacqueline Rolls Jun 2014

Using Otolith Elemental Composition To Track The Habitat Use, Movements, And Life History Patterns Of Common Snook (Centropomus Undecimalis) And Red Drum (Sciaenops Ocellatus) In The Tampa Bay Estuary, Holly Jacqueline Rolls

USF Tampa Graduate Theses and Dissertations

Knowledge of fish habitat use and connectivity is critical for understanding the structure and dynamics of fish populations and, therefore, necessary for the implementation of successful fisheries management strategies. Tagging is an effective means of providing such information, and the elemental composition contained within fish otoliths is increasingly being used as a natural tag. The chemical composition of otoliths reflects the incorporation of elements from different water bodies and can thus be used to understand the habitat use, movements, and life history patterns of fishes. To assess the applicability of otolith elemental composition as a tagging technique within the Tampa …


Factors In Long-Term Algal Composition Of Cayman Reefs: Determining Effects Of Natural Disturbance And Grazer Pressures, Patrick J. Doughty Jun 2014

Factors In Long-Term Algal Composition Of Cayman Reefs: Determining Effects Of Natural Disturbance And Grazer Pressures, Patrick J. Doughty

Lawrence University Honors Projects

Abstract. Current research shows a worldwide shift in the population dynamics of reefs attributed to increasing human disturbance. With increasing nutrient additions, competitive populations of turf and macroalgae bloom and dominate coral reefs leading to decreased health of the reef as a whole. Unfortunately, few studies have been done showing the long-term changes in algae composition on reefs. In order to find the significant factors in the long-term composition of algae on reefs, algae and fish abundance data were collected through the Lawrence University Marine Program and analyzed for this study. Algae were split into three functional groups: encrusting, turf …


West Coast Rock Lobster Harvest Strategy And Control Rules 2014 - 2019, Western Australian Department Of Fisheries Jun 2014

West Coast Rock Lobster Harvest Strategy And Control Rules 2014 - 2019, Western Australian Department Of Fisheries

Fisheries Management Papers

The Fish Resources Management Act 1994 (the Act) provides the overarching legislative framework for management of the West Coast Rock Lobster Fishery (the Fishery). The objects of the Act are: (a) to develop and manage fisheries and aquaculture in a sustainable way; and (b) to share and conserve the State’s fish and other aquatic resources and their habitats for the benefit of present and future generations.


West Coast Rock Lobster Harvest Strategy And Control Rules : 2014 – 2019, Department Of Fisheries Jun 2014

West Coast Rock Lobster Harvest Strategy And Control Rules : 2014 – 2019, Department Of Fisheries

Fisheries Management Papers

No abstract provided.


Distribution And Dynamic Habitat Use Of Young Bull Sharks Carcharhinus Leucas In A Highly Stratified Northern Gulf Of Mexico Estuary, J. Marcus Drymon, Matthew J. Ajemian, Sean P. Powers May 2014

Distribution And Dynamic Habitat Use Of Young Bull Sharks Carcharhinus Leucas In A Highly Stratified Northern Gulf Of Mexico Estuary, J. Marcus Drymon, Matthew J. Ajemian, Sean P. Powers

University Faculty and Staff Publications

Understanding how animals alter habitat use in response to changing abiotic conditions is important for effective conservation management. For bull sharks (Carcharhinus leucas), habitat use has been widely examined in the eastern and western Gulf of Mexico; however, knowledge of their movements and the factors influencing them is lacking for populations in the more temperate north-central Gulf of Mexico. To examine how changes in hydrographic conditions affected the presence of young bull sharks in Mobile Bay, Alabama, thirty-five sharks were fitted with internal acoustic transmitters and monitored with an acoustic monitoring array consisting of thirty-three receivers between June …


Detection Of Pahs In Commercial And Wild Caught Fish Oil Using Scanning Fluorescence Spectroscopy, Edwin Antonio Pena May 2014

Detection Of Pahs In Commercial And Wild Caught Fish Oil Using Scanning Fluorescence Spectroscopy, Edwin Antonio Pena

Seton Hall University Dissertations and Theses (ETDs)

The DeepWater Horizon (DWH) oil spill contaminated a large area in the Gulf of Mexico in summer 2010. It is likely that many aquatic species in the Gulf were affected by the spill. Crude oil contains polycyclic aromatic hydrocarbon (PAHs). Some PAHs are carcinogenic to fish and humans. The purpose of this project was to develop menhaden fish oil as a biomonitoring tool for crude oil contaminants such as PAHs using scanning fluorescence spectroscopy (SFS). Menhaden (Genus Brevoortia) is one of the most ecologically and economically important marine fish species along the Atlantic and Gulf coast; however, it is …


Harvest Incentives: A Tool For Managing Aquatic Invasive Species, Bob Wiltshire, Nathan Stone, Marshall Meyers, Bill Hyatt, Lori Williams, Jason Goldberg, Susan Pasko, Leah Elwell May 2014

Harvest Incentives: A Tool For Managing Aquatic Invasive Species, Bob Wiltshire, Nathan Stone, Marshall Meyers, Bill Hyatt, Lori Williams, Jason Goldberg, Susan Pasko, Leah Elwell

National Invasive Species Council

Conclusion

The success of any harvest incentive program to address aquatic invasive species will depend upon numerous biological, socioeconomic, and legal considerations. Programs that encourage harvest may be a successful management tool in targeting small, distinct populations; in high priority areas within a larger invasion; or they may play a supplementary role within larger control programs. Their use, however, will require careful review, planning, and monitoring to ensure success and that they do not unintentionally lead to further spread of invasive species, cause additional harm to native species, or waste valuable resources.


Phenotypic Variation In The Model Organism, Danio Rerio, Rachel D. Champaigne, Kim H. Brown May 2014

Phenotypic Variation In The Model Organism, Danio Rerio, Rachel D. Champaigne, Kim H. Brown

Student Research Symposium

Model organisms are used to study evolutionary conserved traits. Zebrafish (Danio rerio) are used a model organism because of their highly fecundity, external fertilization, and robust nature, making them highly adaptable to environmental and genetic variation. In an effort to limit data variation that lies outside of topic interest, phenotypic measures of variation must be performed, understood, and taken into consideration for future studies. A common measurement of phenotypic variation in fish is in the maximum (Ucrit) swimming speeds. Inter and intra-strain variation in zebrafish Ucrit swimming speeds will be observed in a swim tunnel. Baseline values will …


Transcriptome Analysis Of Sea Lamprey Embryogenesis, Zakary Ilya Yermolenko May 2014

Transcriptome Analysis Of Sea Lamprey Embryogenesis, Zakary Ilya Yermolenko

Seton Hall University Dissertations and Theses (ETDs)

The sea lamprey (Petromyzon marinus) has survived throughout evolution for hundreds of millions of years. It is considered an invasive species to the Great Lakes that has caused dramatic changes in the ecosystem for fish communities resulting in the collapse of a fishing industry that was previously valued at billions of dollars. Successful management of the sea lamprey is essential to a sustainable fishing industry and biodiversity. Therefore sea lamprey embryos were studied at various stages of development by growing them in a simulated habitat. RNAs from adult female ovaries and embryos at different time points during embryogenesis …


A Likelihood Analysis Of The Introduction Of Marine Pests To Western Australian Ports Via Commercial Vessels, Samantha D. Bridgwood, Justin I. Mcdonald May 2014

A Likelihood Analysis Of The Introduction Of Marine Pests To Western Australian Ports Via Commercial Vessels, Samantha D. Bridgwood, Justin I. Mcdonald

Fisheries Research Reports

The following document is an analysis of the likelihood of an introduced marine pest (IMP) being translocated by commercial vessels into Western Australian (WA) state waters. This analysis is presented at the bioregional level (North Coast, Gascoyne Coast, West Coast and South Coast bioregions) and at the port level. The ports include: Albany, Broome, Bunbury, Dampier, Esperance, Fremantle, Geraldton, Port Hedland, Useless Loop and Wyndham. The analyses are based on vessel data supplied by the ports for the period of 2011. As such, all outputs and assumptions are based on data from that period and while the likelihood may change …


Status Of Demersal Finfish Stocks On The West Coast Of Australia, David V. Fairclough, Brett W. Molony, Brett M. Crisafulli, Ian S. Keay, Sybrand Alexander Hesp, Ross J. Marriott May 2014

Status Of Demersal Finfish Stocks On The West Coast Of Australia, David V. Fairclough, Brett W. Molony, Brett M. Crisafulli, Ian S. Keay, Sybrand Alexander Hesp, Ross J. Marriott

Fisheries Research Reports

Assessments of the key indicator species for the West Coast Demersal Scalefish Resource (WCDSR; West Australian dhufish Glaucosoma hebraicum, Snapper Pagrus auratus and Baldchin groper Choerodon rubescens) in 2007 and 2009 demonstrated that the stocks were experiencing overfishing. Thus, between late 2007 and early 2010, substantial changes were made to the management of the commercial and recreational fisheries that exploit the WCDSR. These were designed to reduce catches of the entire suite of demersal scalefish species (and of each indicator species) by both the commercial and recreational sectors in the West Coast Bioregion (WCB) by at least 50 % of …


Production Of A Soybean Meal With High-Protein And Low Anti-Nutritional Factors For Fish Feed, Maria De Las Mercedes Castro May 2014

Production Of A Soybean Meal With High-Protein And Low Anti-Nutritional Factors For Fish Feed, Maria De Las Mercedes Castro

Graduate Theses and Dissertations

Aquaculture is one of the fastest growing areas of the food production system. According to the FAO, its rise is expected to continue through the year 2030 in order to maintain per-capita consumption levels required for the increasing population. Fishmeal--obtained from wild-harvested fish--has been the source of protein for fish feed. However, data indicates that these fish harvests are in decline, which could restrain that growth. The possibility of a shortage of fishmeal prompted the industry to look into possible alternatives. Soybean meal appears as a promising substitute since it is an affordable high quality source of protein. However, the …


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 …