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Full-Text Articles in Aquaculture and Fisheries

Rational Ecosystem-Based Fisheries Management: An Application To The Gom Commercial Reef Fish Fishery, Quinn Weninger May 2019

Rational Ecosystem-Based Fisheries Management: An Application To The Gom Commercial Reef Fish Fishery, Quinn Weninger

Economics Working Papers

Ecosystem-based fisheries management (EBFM) seeks to integrate the complexity of real-world marine ecosystems into the design of fisheries policies and regulations. EBFM is practiced currently with the help of complex ecosystem process models that track and simulate ecosystem function and outcomes under competing model formulations and management plans. To maintain tractability, the fishing sector component of process models maintain restrictive assumptions for multiple species harvesting technologies, fishing behavioral rules, and fishing sector responses to changing stock conditions. Predictions of fishing sector-ecosystem interaction obtained under these assumptions can grossly misinform EBFM policy design. An alternative rational fishing model is presented and ...


Influence Of Amino Acid Supplementations In Juvenile Yellow Perch Fed Plant Protein Combinations, Aaron J. Von Eschen, Michael L. Brown, Kurt A. Rosentrater Apr 2019

Influence Of Amino Acid Supplementations In Juvenile Yellow Perch Fed Plant Protein Combinations, Aaron J. Von Eschen, Michael L. Brown, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

Distillers dried grains with solubles (DDGS) in combination with soy protein concentrate (SPC) with and without an essential amino acid (EAA) complex were assessed as protein alternatives in juvenile Yellow Perch Perca flavescens diets. Diets contained 5% FM, 40% SPC, and 20% or 40% DDGS each with or without EAA. No mortalities or health assessment differences were observed during the trial and all fish readily accepted the experimental diets. Diets supplemented with EAA produced greater weight gain, improved feed conversion, and apparent protein digestibility. Performance was consistently improved for fish fed diets containing amino acid supplements. Based on these results ...


Identification Of Resource Extraction Technologies When The Resource Stock Is Unobservable, Quinn Weninger, Larry Perruso, Helle Bunzel Feb 2019

Identification Of Resource Extraction Technologies When The Resource Stock Is Unobservable, Quinn Weninger, Larry Perruso, Helle Bunzel

Economics Working Papers

This paper consistently estimates the structural properties of a fishery resource extraction technology. We overcome two ubiquitous features of fisheries data generating processes that invalidate classical estimators: unobservability by the researcher (but partial observability by fishermen) of the fish stock, and endogenous production decisions that vary with private information about stock abundance and economic variables. We adopt methods used in fisheries stock assessment to control for unobserved stock effects on productivity. A nonlinear instrumental variables estimator controls for endogenous choices of the output mix. The approach is applied to the US Gulf of Mexico commercial reef fish fishery. Comparison with ...


An Annotated Genome For Haliotis Rufescens (Red Abalone) And Resequenced Green, Pink, Pinto, Black And White Abalone Species, Rick E. Masonbrink, Catherine Purcell, Sara Boles, Andrew Whitehead, John Hyde, Arun S. Seetharam, Andrew J. Severin Jan 2019

An Annotated Genome For Haliotis Rufescens (Red Abalone) And Resequenced Green, Pink, Pinto, Black And White Abalone Species, Rick E. Masonbrink, Catherine Purcell, Sara Boles, Andrew Whitehead, John Hyde, Arun S. Seetharam, Andrew J. Severin

Genome Informatics Facility Publications

Abalone are one of the few marine taxa where aquaculture production dominates the global market as a result of increasing demand and declining natural stocks from overexploitation and disease. To better understand abalone biology, aid in conservation efforts for endangered abalone species, and gain insight into sustainable aquaculture, we created a draft genome of the red abalone (Haliotis rufescens). The approach to this genome draft included initial assembly using raw Illumina and PacBio sequencing data with MaSuRCA, before scaffolding using sequencing data generated from Chicago library preparations with HiRise2. This assembly approach resulted in 8,371 scaffolds and total length ...


Rational Ecosystems-Based Fisheries Management, Rajesh Singh, Quinn Weninger Aug 2018

Rational Ecosystems-Based Fisheries Management, Rajesh Singh, Quinn Weninger

Economics Working Papers

Ecosystem-based fisheries management (EBFM) seeks to incorporate the full complexity of marine ecosystems into the design of fisheries management policies and regulations. This paper presents a model of a multiple-species, and spatially-temporally heterogeneous fishery that is managed under a tradable quota regulation. Past studies of fisheries management in this setting have, for purposes of simplification, resorted to (1) restrictive assumptions for multiple-species harvesting technologies, (2) myopic and ad hoc behavioral rules for the fishing sector, and (3) assumptions for regulatory control that do not exist in real world fisheries. We derive a rational expectations, ecological-economic equilibrium outcome for harvests, discards ...


Techno-Economic Analysis (Tea) Of Extruded Aquafeeds, Rashid Suleiman, Kurt A. Rosentrater Jul 2018

Techno-Economic Analysis (Tea) Of Extruded Aquafeeds, Rashid Suleiman, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

The worldwide decline and overexploitation of ocean fisheries stocks had provided an incentive for the rapid growth of aquaculture. The aquaculture industry has been recognized as the fastest-growing food production system globally, with a 10% increase in production per year and is one of the most reliable and sustainable growth markets for manufactured feeds. Extrusion technology has been extensively used in the modern aquatic feed manufacturing, due to nutritional, physical properties improvements and cost effectiveness of feeds. Cost related to aquatic feed remains the biggest challenge, especially for small-scale producers. In order to understand costs and potential breakeven points, a ...


Floods, Drying, Habitat Connectivity, And Fish Occupancy Dynamics In Restored And Unrestored Oxbows Of West Central Iowa, Usa, Jesse R. Fischer, Bryan D. Bakevich, Colin P. Shea, Clay L. Pierce, Michael C. Quist Apr 2018

Floods, Drying, Habitat Connectivity, And Fish Occupancy Dynamics In Restored And Unrestored Oxbows Of West Central Iowa, Usa, Jesse R. Fischer, Bryan D. Bakevich, Colin P. Shea, Clay L. Pierce, Michael C. Quist

Natural Resource Ecology and Management Publications

1. In the agricultural landscape of the Midwestern USA, waterways are highly altered. Oxbows are among the few remaining off‐channel habitats associated with streams, supporting fish assemblages that include the endangered Topeka shiners Notropis topeka in portions of their remaining range. Oxbow restorations seek to increase the number and quality of oxbows for Topeka shiners. For oxbows to provide optimal habitat, periods of isolation from streams and connection with streams during floods are necessary.

2. Water levels and patterns of drying and hydrological connectivity between 12 oxbows and their neighboring streams in West Central Iowa were continuously monitored from ...


Insights Into Teleost Sex Determination From The Seriola Dorsalis Genome Assembly, Catherine M. Purcell, Arun S. Seetharam, Owyn Snodgrass, Sofia Ortega-García, John R. Hyde, Andrew J. Severin Jan 2018

Insights Into Teleost Sex Determination From The Seriola Dorsalis Genome Assembly, Catherine M. Purcell, Arun S. Seetharam, Owyn Snodgrass, Sofia Ortega-García, John R. Hyde, Andrew J. Severin

Office of Biotechnology Publications

Background: The assembly and annotation of a genome is a valuable resource for a species, with applications ranging from conservation genomics to gene discovery. Genomic resource development is especially important for species in culture, such as the California Yellowtail (Seriola dorsalis), the likely candidate for the establishment of commercial offshore aquaculture production in southern California. Genomic resource development for this species will improve the understanding of sex and other phenotypic traits, and allow for rapid increases in genetic improvement for and economic gain in culture production.

Results: We describe the assembly and annotation of the S. dorsalis genome, and present ...


An Overview Of Aquaponic Systems: Hydroponic Components, D. Allen Pattillo Mar 2017

An Overview Of Aquaponic Systems: Hydroponic Components, D. Allen Pattillo

NCRAC Technical Bulletins

Aquaponics is the union of hydroponics (growing plants without soil) and aquaculture (farming fish or other aquatic organisms) for a fast, efficient method of producing both plant and fish crops. Fish waste from the aquaculture portion of the system, is broken down by bacteria into dissolved nutrients (e.g., nitrogen and phosphorus compounds) that plants utilize to grow in a hydroponic unit. This nutrient removal not only improves water quality for the fish but also decreases overall water consumption by limiting the amount released as effluent.


Aquaculture Genomics, Genetics And Breeding In The United States: Current Status, Challenges, And Priorities For Future Research, The Aquaculture Genomics, Genetics And Breeding Workshop, Andrew J. Severin, Et Al Jan 2017

Aquaculture Genomics, Genetics And Breeding In The United States: Current Status, Challenges, And Priorities For Future Research, The Aquaculture Genomics, Genetics And Breeding Workshop, Andrew J. Severin, Et Al

Genome Informatics Facility Publications

Advancing the production efficiency and profitability of aquaculture is dependent upon the ability to utilize a diverse array of genetic resources. The ultimate goals of aquaculture genomics, genetics and breeding research are to enhance aquaculture production efficiency, sustainability, product quality, and profitability in support of the commercial sector and for the benefit of consumers. In order to achieve these goals, it is important to understand the genomic structure and organization of aquaculture species, and their genomic and phenomic variations, as well as the genetic basis of traits and their interrelationships. In addition, it is also important to understand the mechanisms ...


3d Maldi Mass Spectrometry Imaging Of A Single Cell: Spatial Mapping Of Lipids In The Embryonic Development Of Zebrafish, Maria Emilia Duenas, Jeffrey J. Essner, Young Jin Lee Jan 2017

3d Maldi Mass Spectrometry Imaging Of A Single Cell: Spatial Mapping Of Lipids In The Embryonic Development Of Zebrafish, Maria Emilia Duenas, Jeffrey J. Essner, Young Jin Lee

Chemistry Publications

The zebrafish (Danio rerio) has been widely used as a model vertebrate system to study lipid metabolism, the roles of lipids in diseases, and lipid dynamics in embryonic development. Here, we applied high-spatial resolution matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry imaging (MSI) to map and visualize the three-dimensional spatial distribution of phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamines (PE), and phosphatidylinositol (PI), in newly fertilized individual zebrafish embryos. This is the first time MALDI-MSI has been applied for three dimensional chemical imaging of a single cell. PC molecular species are present inside the yolk in addition to the blastodisc, while PE ...


Effects Of Land Use And Invasive Fishes On Prairie Pothole Wetland Condition, Michael David Sundberg Jan 2016

Effects Of Land Use And Invasive Fishes On Prairie Pothole Wetland Condition, Michael David Sundberg

Graduate Theses and Dissertations

Prairie pothole wetlands provide many valuable ecosystem services. However, land use changes in the prairie pothole region (PPR) have increased contaminant loadings and facilitated invasions by fishes, leading to declines in biological diversity and wetland condition. Primary objectives of my thesis research were to 1) quantify direct and indirect relationships among nine environmental attributes, including land use, wetland water volume, herbicides, chloride, invasive fishes, turbidity, plant and invertebrate assemblages, and tiger salamander Ambystoma tigrinum abundance, 2) use these relationships to identify a set of wetland condition metrics, and 3) evaluate how wetland ecosystems responded when invasive fishes were eliminated following ...


Place-Based Communities And Neoliberalism: A Study Of The Artisanal Fishing Community Of Chorrillos, Peru, Héctor Andrés Bombiella Medina Jan 2016

Place-Based Communities And Neoliberalism: A Study Of The Artisanal Fishing Community Of Chorrillos, Peru, Héctor Andrés Bombiella Medina

Graduate Theses and Dissertations

This dissertation is about artisanal fishers in Chorrillos, a small bay near the southern edge of Lima, Peru, and how they use place as an instrument to defend their access to fishing resources on Peru's central coast. The context of this research work includes global neoliberal influences on the Peruvian state and the negotiation of global and local economics, politics, and social issues. Over the last decade, depletion in fish stocks has led to tensions between industrial and artisanal fishers, and demands from the industrial sector to reduce Peruvian state protections for artisanal fishers. Not only are Chorrillos's ...


Microbiome Analyses Of Pacific White Shrimp (Litopenaeus Vannamei) Collected From Disparate Geographical Locations, Arun S. Seetharam, Emily Kawaler, Zhi-Qiang Du, Max F. Rothschild, Andrew J. Severin Dec 2015

Microbiome Analyses Of Pacific White Shrimp (Litopenaeus Vannamei) Collected From Disparate Geographical Locations, Arun S. Seetharam, Emily Kawaler, Zhi-Qiang Du, Max F. Rothschild, Andrew J. Severin

Genome Informatics Facility Publications

In this study, the tail muscle microbiota of pacific white shrimp (Litopenaeus vannamei) sourced from five countries across Central and South America and Southeast Asia were determined and compared. The genomic DNA was sequenced at around 10 × coverage for each geographical location and was assembled de novo for comparative analysis. The assembled sequences for all the lines were classified based on their similarity to the sequences in the public database. We found that there is high correlation among the microbiota of shrimp from disparate regions, as well as the presence of some DNA from bacteria known to cause food poisoning ...


Techno-Economic Analysis (Tea) And Life-Cycle Assessment (Lca) Of Extruded Aquafeed, Chinwendu F. Ozoh, Kurt A. Rosentrater Jul 2015

Techno-Economic Analysis (Tea) And Life-Cycle Assessment (Lca) Of Extruded Aquafeed, Chinwendu F. Ozoh, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

The increasing world population has led to higher demand for protein source; Fish is a very good source of protein for humans. Hence, the need for more farmed fish. The aquaculture industry has been recognized as the fastest growing food production system globally, with a 10% increase in production every year. It is also one of the sustainable and reliable growth market for manufactured feed. This study was carried out to optimize cost and environmental performance in the production of aquaculture feed for small scale producers. Techno-economic analysis (TEA) and Life-cycle assessment (LCA) were tools for the analysis. In this ...


Life Cycle Assessment (Lca) And Techno-Economic Analysis (Tea) Of Tilapia-Basil Aquaponics, Kun Xie, Kurt A. Rosentrater Jul 2015

Life Cycle Assessment (Lca) And Techno-Economic Analysis (Tea) Of Tilapia-Basil Aquaponics, Kun Xie, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

Aquaponics is the system combining hydroponic and aquaculture, in which fish and plants are raised together, and they can be beneficial from each other as well as to each other. When the system is maintained properly and is in a balance status, aquaponics will mimic the natural ecosystem, use much less water than traditional aquaculture, and have almost no effluent. As a result, it is thought more environmentally friendly and sustainable. In this study, both Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) of a tilapia and basil aquaponic system were conducted. Three scales, including a truly running system, pilot ...


Sequencing A Shrimp Diversity Panel, Emily Kawaler, Max F. Rothschild, Zhiqiang Du Jan 2015

Sequencing A Shrimp Diversity Panel, Emily Kawaler, Max F. Rothschild, Zhiqiang Du

Animal Industry Report

Eighty-six shrimp (eighty Pacific White, six Tiger shrimp) from ten different geographic regions were sequenced with a twofold goal: first, to better understand and document the genetic makeup of the species, and second, to discover genetic differences between shrimp lines that may facilitate the breeding of shrimp with better performance traits


Urban Fisheries Investigation: Development Of A Site Selection Method For Central Iowa's Urban Ponds, Steven J. Konrady Jan 2015

Urban Fisheries Investigation: Development Of A Site Selection Method For Central Iowa's Urban Ponds, Steven J. Konrady

Graduate Theses and Dissertations

Waning fishing license sales over several decades has provided an impetus for reconnecting with Iowa's 64% urban majority and a modern angler unable or unwilling to travel great distances to fish. One result has been the recent urban fisheries assessments and improvements in Iowa, active in some form for nearly a decade. The goal of the current state project is to establish sustainable fishery resources for Iowa's urban areas. A cooperative effort between the Iowa Department of Natural Resources and Iowa State University focused on assessing a nine-county area in central Iowa from 2010 to 2014. The study ...


Ncbi-Blast Programs Optimization On Xsede Resources For Sustainable Aquaculture, Arun S. Seetharam, Antonio Gomez, Catherine M. Purcell, John R. Hyde, Philip D. Blood, Andrew J. Severin Jan 2015

Ncbi-Blast Programs Optimization On Xsede Resources For Sustainable Aquaculture, Arun S. Seetharam, Antonio Gomez, Catherine M. Purcell, John R. Hyde, Philip D. Blood, Andrew J. Severin

Genome Informatics Facility Conference Proceedings

The development of genomic resources of non-model organisms is now becoming commonplace as the cost of sequencing continues to decrease. The Genome Informatics Facility in collaboration with the Southwest Fisheries Science Center (SWFSC), NOAA is creating these resources for sustainable aquaculture in Seriola lalandi. Gene prediction and annotation are common steps in the pipeline to generate genomic resources, which are computationally intense and time consuming. In our steps to create genomic resources for Seriola lalandi, we found BLAST to be one of our most rate limiting steps. Therefore, we took advantage of our XSEDE Extended Collaborative Support Services (ECSS) to ...


Life Cycle Assessment (Lca) And Techno-Economic Analysis (Tea) Of Various Biosystems, Kun Xie Jan 2015

Life Cycle Assessment (Lca) And Techno-Economic Analysis (Tea) Of Various Biosystems, Kun Xie

Graduate Theses and Dissertations

The fast-growing world population prompts researchers to evaluate both environmental and economic impacts during manufacture and service processing. Distillers dried grains with solubles (DDGS) fractionation and aquaponics are two bioprocesses aiming to make full use of materials and resources. This study conducted Life cycle assessment (LCA) and Techno-economic analysis (TEA) for DDGS fractionation and tilapia-basil aquaponics.

DDGS mainly contains protein, oil, fiber, and ash. DDGS could have more economic value and wider use if it could be separated into higher protein fraction and higher fiber fraction. In our work, the optimization of three parameters of a gravity separator (side slope ...


Pesticide Concentrations In Frog Tissue And Wetland Habitats In A Landscape Dominated By Agriculture, Kelly L. Smalling, Rebecca A. Reeves, Erin Muths, Mark Vandever, William A. Battaglin, Michelle L. Hladik, Clay L. Pierce Jan 2015

Pesticide Concentrations In Frog Tissue And Wetland Habitats In A Landscape Dominated By Agriculture, Kelly L. Smalling, Rebecca A. Reeves, Erin Muths, Mark Vandever, William A. Battaglin, Michelle L. Hladik, Clay L. Pierce

Natural Resource Ecology and Management Publications

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of twonative amphibian species Pseudacris maculata (chorus frogs) and Lithobates ...


Status Of The Topeka Shiner In West-Central Iowa, Bryan David Bakevich, Clay L. Pierce, Michael C. Quist Jan 2015

Status Of The Topeka Shiner In West-Central Iowa, Bryan David Bakevich, Clay L. Pierce, Michael C. Quist

Natural Resource Ecology and Management Publications

The Topeka shiner Notropis topeka is a federally endangered fish species that is estimated to occupy only 20% of its historic range. In Iowa Topeka shiners have been in decline for decades. Our goal was to determine the present distribution of Topeka shiners in the west-central portion of their range in Iowa and to characterize the extent of its decline. We compared the current distribution to distributions generated from earlier collections. We found Topeka shiners in six of 22 watersheds where they occurred historically. Status of Topeka shiners was judged to be stable in 27% of the watersheds, at risk ...


The Effect Of A Mycotoxin Deactivation Product On Growth Of Juvenile Rainbow Trout Fed Distillers Dried Grains, Wendy M. Sealey, Christopher G. Hooley, Kurt A. Rosentrater, T. Gibson Gaylord, Frederic T. Barrows Jan 2015

The Effect Of A Mycotoxin Deactivation Product On Growth Of Juvenile Rainbow Trout Fed Distillers Dried Grains, Wendy M. Sealey, Christopher G. Hooley, Kurt A. Rosentrater, T. Gibson Gaylord, Frederic T. Barrows

Agricultural and Biosystems Engineering Publications

Distillers dried grains (DDG) with solubles (DDGS) is a product that has shown potential as a protein source for some fish species, but high inclusion rates of DDGS have not always been successfully achieved for Rainbow Trout Oncorhynchus mykiss. Our objective was to determine whether inclusion of a mycotoxin deactivation product (Biofix Plus) could improve the ability of high-protein DDG (HPDDG) to replace a portion of the fish meal in diets for Rainbow Trout. The 2 × 2 factorial feeding trial examined protein source (menhaden fish meal [MFM] or HPDDG) with or without Biofix Plus. A control diet (42% digestible protein ...


A Food Web Modeling Analysis Of A Midwestern, Usa Eutrophic Lake Dominated By Non-Native Common Carp And Zebra Mussels, Michael E. Colvin, Clay L. Pierce, Timothy W. Stewart Jan 2015

A Food Web Modeling Analysis Of A Midwestern, Usa Eutrophic Lake Dominated By Non-Native Common Carp And Zebra Mussels, Michael E. Colvin, Clay L. Pierce, Timothy W. Stewart

Natural Resource Ecology and Management Publications

Food web modeling is recognized as fundamental to understanding the complexities of aquatic systems.Ecopath is the most common mass-balance model used to represent food webs and quantify trophic inter-actions among groups. We constructed annual Ecopath models for four consecutive years during the firsthalf-decade of a zebra mussel invasion in shallow, eutrophic Clear Lake, Iowa, USA, to evaluate changesin relative biomass and total system consumption among food web groups, evaluate food web impactsof non-native common carp and zebra mussels on food web groups, and to interpret food web impactsin light of on-going lake restoration. Total living biomass increased each year ...


Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce Oct 2014

Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce

Natural Resource Ecology and Management Publications

Nonwadeable rivers are unique ecosystems that support high levels of aquatic biodiversity, yet they have been greatly altered by human activities. Although riverine fish assemblages have been studied in the past, we still have an incomplete understanding of how fish assemblages respond to both natural and anthropogenic influences in large rivers. The purpose of this study was to evaluate associations between fish assemblage structure and reach-scale habitat, dam, and watershed land use characteristics. In the summers of 2011 and 2012, comprehensive fish and environmental data were collected from 33 reaches in the Iowa and Cedar rivers of eastern-central Iowa. Canonical ...


Techno-Economic Analysis (Tea) Of Extruded Aquafeeds, Rashid A. Suleiman, Chenxu Yu, Kurt A. Rosentrater Jul 2014

Techno-Economic Analysis (Tea) Of Extruded Aquafeeds, Rashid A. Suleiman, Chenxu Yu, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

The worldwide decline and overexploitation of ocean fisheries stocks had provided incentive for rapid growth of aquaculture. The aquaculture industry has been recognized as the fastest-growing food production system globally, with a 10% increases in production per year, and is one of the most reliable and sustainable growth markets for manufactured feeds. Extrusion technology has been extensively used in the modern aquatic feed manufacturing, due to nutritional, physical properties improvements and cost effectiveness of feeds. Cost related to aquatic feed remains the biggest challenge, especially for small-scale producers. In this study a single screw extruders and three different scenarios (i ...


Fish Assemblage Relationships With Physical Characteristics And Presence Of Dams In Three Eastern Iowa Rivers, Clay L. Pierce, N. L. Ahrens, A. K. Loan-Wilsey, G. A. Simmons, G. T. Gelwicks May 2014

Fish Assemblage Relationships With Physical Characteristics And Presence Of Dams In Three Eastern Iowa Rivers, Clay L. Pierce, N. L. Ahrens, A. K. Loan-Wilsey, G. A. Simmons, G. T. Gelwicks

Natural Resource Ecology and Management Publications

Fish assemblages in rivers of the Midwestern United States are an important component of the region's natural resources and biodiversity. We characterized the physical environment and presence of dams in a series of reaches in three eastern Iowa rivers tributary to the Mississippi River and related these characteristics to the fish assemblages present. Some physical characteristics were similar among the 12 study reaches, whereas others differed substantially. We found a total of 68 species across the 12 study reaches; 56 in the Turkey River, 51 in the Maquoketa River and 50 in the Wapsipinicon River. Seventeen species could be ...


Greenhouse Production Of High-Value Crops In An Aquaponic System, David Allen Pattillo Jan 2014

Greenhouse Production Of High-Value Crops In An Aquaponic System, David Allen Pattillo

Leopold Center Completed Grant Reports

This project evaluates the long-term practicality of the aquaponic enterprise for economic and environmental sustainability. The investigator is comparing three types of plant-growing materials(rock wool, pea gravel and floating rafts) in a recirculating aquaponic system to grow basil, lettuce and Nile tilapia. Future plans include use of native yellow perch in the system rather than the non-native tilapia.


Historical Changes In Fish Assemblage Structure In Midwestern Nonwadeable Rivers, Timothy Parks, Michael C. Quist, Clay L. Pierce Jan 2014

Historical Changes In Fish Assemblage Structure In Midwestern Nonwadeable Rivers, Timothy Parks, Michael C. Quist, Clay L. Pierce

Natural Resource Ecology and Management Publications

Historical change in fish assemblage structure was evaluated in the mainstems of the Des Moines, Iowa, Cedar, Wapsipinicon, and Maquoketa rivers, in Iowa. Fish occurrence data were compared in each river between historical and recent time periods to characterize temporal changes among 126 species distributions and assess spatiotemporal patterns in faunal similarity. A resampling procedure was used to estimate species occurrences in rivers during each assessment period and changes in species occurrence were summarized. Spatiotemporal shifts in species composition were analyzed at the river and river section scale using cluster analysis, pairwise Jaccard's dissimilarities, and analysis of multivariate beta ...


Exogenous Application Of Estradiol To Eggs Unexpectedly Induces Male Development In Two Turtle Species With Temperaturedependent Sex Determination, Daniel A. Warner, Elizabeth Addis, Wei-Guo Du, Thane Wibbels, Fredric J. Janzen Jan 2014

Exogenous Application Of Estradiol To Eggs Unexpectedly Induces Male Development In Two Turtle Species With Temperaturedependent Sex Determination, Daniel A. Warner, Elizabeth Addis, Wei-Guo Du, Thane Wibbels, Fredric J. Janzen

Ecology, Evolution and Organismal Biology Publications

Steroid hormones affect sex determination in a variety of vertebrates. The feminizing effects of exposure to estradiol and the masculinizing effects of aromatase inhibition during development are well established in a broad range of vertebrate taxa, but paradoxical findings are occasionally reported. Four independent experiments were conducted on two turtle species with temperature-dependent sex determination (Chrysemys picta and Chelydra serpentina) to quantify the effects of egg incubation temperature, estradiol, and an aromatase inhibitor on offspring sex ratios. As expected, the warmer incubation temperatures induced female development and the cooler temperatures produced primarily males. However, application of an aromatase inhibitor had ...