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Full-Text Articles in Aquaculture and Fisheries

The Influence Of Habitat Preference On Longitudinal Population Composition And Distribution Of Groupers (Serranidae) In Chumbe Island Coral Park, Zanzibar Tanzania, Caroline Daley Oct 2018

The Influence Of Habitat Preference On Longitudinal Population Composition And Distribution Of Groupers (Serranidae) In Chumbe Island Coral Park, Zanzibar Tanzania, Caroline Daley

Independent Study Project (ISP) Collection

A survey of six common grouper (Serranidae) species was conducted on both the western protected and eastern unprotected reefs around Chumbe Island. Species, estimated maturity, and fundamental niche and general habitat preference was extrapolated based on observed realized niche and qualified according to substrate, depth, slope position, and general reef region. Abundance, biomass density, and biodiversity of Serranid populations were compared among locations on the reef with habitat preference in mind in order to best assess how habitat influences population composition, distribution, and health. The results of this study provide depth to previous research on the protected reef and indicate …


Short-Term Low Salinity Mitigates Effects Of Oil And Dispersant On Juvenile Eastern Oysters: A Laboratory Experiment With Implications For Oil Spill Response Activities, Meagan N. Schrandt, Sean Powers, F.Scott Rikard, Wilawan Thongda, Eric Peatman Sep 2018

Short-Term Low Salinity Mitigates Effects Of Oil And Dispersant On Juvenile Eastern Oysters: A Laboratory Experiment With Implications For Oil Spill Response Activities, Meagan N. Schrandt, Sean Powers, F.Scott Rikard, Wilawan Thongda, Eric Peatman

University Faculty and Staff Publications

Following the Deepwater Horizon oil spill, eastern oyster (Crassostrea virginica) reefs in the northern Gulf of Mexico were exposed to oil and various associated clean-up activities that may have compromised oyster reef health. Included in the exposure was oil, dispersant, and in some locales, atypical salinity regimes. Oil and dispersants can be detrimental to oysters and the effects of salinity depend on the level. In addition to these extrinsic factors, genetic diversity of oyster populations may help the oysters respond to stressors, as demonstrated in other systems. We used a 3×3×2 factorial design to experimentally examine the effects …


Adult Walleye Abundance And Subsequent Fry Production In The Tamarac River, Mn, Phillip Oswald Sep 2018

Adult Walleye Abundance And Subsequent Fry Production In The Tamarac River, Mn, Phillip Oswald

Biology Graduate Theses

Walleye reproductive success is of critical interest for the Red Lakes as this system is maintained entirely by natural reproduction and supports robust commercial and recreational fisheries. The Tamarac River, a major tributary to the Red Lakes, hosts a substantial Walleye spawning migration annually. The river drains the largest peat bog in the lower 48 states and thus experiences low dissolved oxygen at times. It is largely unknown how the potential anoxic bog water affects Walleye reproductive success each year and subsequent year class strength. Fyke nets were set from 2014-2018 to assess the relative abundance of adult Walleye spawning …


Using Local Fishery Monitoring To Understand Small-Scale Coastal Fisheries In Tanzania, Matthew Robertson Aug 2018

Using Local Fishery Monitoring To Understand Small-Scale Coastal Fisheries In Tanzania, Matthew Robertson

LSU Master's Theses

Nearshore marine fisheries provide the main source of protein for nearly 9 million people in the coastal villages of Tanzania, yet for decades the fisheries have shown signs of overexploitation. These fisheries are small-scale and co-managed by local coastal communities in groups known as Beach Management Units (BMUs). BMUs monitor individual fishing trip data (e.g. gear, vessel, taxa); however, these data have only been analyzed in nationally aggregated statistics and to our knowledge, are not presently used in management decision making. The present thesis aimed to identify the forms of data and information that local fishery monitoring can record about …


Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen Aug 2018

Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen

Biology Graduate Theses

Exposure to consistent water warming rates and access to abundant populations of edible sized zooplankton affects growth and increases the probability of survival for newly hatched Yellow Perch Perca flavescens. Seven lakes with varying physical characteristics were selected in north-central Minnesota to study abiotic (water temperature) and biotic (zooplankton community and fish growth) progressions during the spring and early summer (April-June). Mean water temperatures from ice-out to 28 June (11.98-14.62 °C) had significant relationships with mean depth (P < 0.01, R? = 0.85), max depth (P < 0.01, R? = 0.73), and total volume (P < 0.01, R2 = 0.54). Hatch periods ranged from 13 to 19 days in 2015 and 13 to 25 days in 2016. Cumulative degree-days (CDD) were used to predict Yellow Perch hatch periods and explain growth. CDD predicted 21-81% of hatch periods in 2015 and 11-50% in 2016. Mean predicted total lengths at 28 June were 19.65-30.41 mm in 2015 and 20.88-28.54 mm in 2016. There was a significant relationship between CDD and predicted total length (R? = 0.62, P < 0.01) to explain differences in Yellow Perch total length while inhabiting the pelagic zone. Observed gape measurements were highly correlated with predicted gapes from the Schael formula (R? = 0.89, P < 0.01) that was used to assess the availability of edible sized zooplankton for age-0 Yellow Perch in each lake. No predator-prey mismatches were found and earlier hatch dates produced age-0 Yellow Perch with greater predicted total lengths in late June on the majority of lakes. This suggests that earlier hatched Yellow perch have an advantage over later hatched Yellow Perch in attaining greater lengths by late June. Our study provides information on a variety of physical and biological progressions in lakes, which may be used for fisheries management practices in the future.


Towards Sustainable Aquafeeds: Evaluating Substitution Of Fishmeal With Lipid-Extracted Microalgal Co-Product (Nannochloropsis Oculata) In Diets Of Juvenile Nile Tilapia (Oreochromis Niloticus), Pallab K. Sarker, Anne R. Kapuscinski, Ashley Y. Bae, Emily Donaldson, Devin S. Fitzgerald, Oliver F. Edelson Jul 2018

Towards Sustainable Aquafeeds: Evaluating Substitution Of Fishmeal With Lipid-Extracted Microalgal Co-Product (Nannochloropsis Oculata) In Diets Of Juvenile Nile Tilapia (Oreochromis Niloticus), Pallab K. Sarker, Anne R. Kapuscinski, Ashley Y. Bae, Emily Donaldson, Devin S. Fitzgerald, Oliver F. Edelson

Dartmouth Scholarship

Microalgae companies increasingly seek markets for defatted biomass that is left over after extracting omega-3 rich oil for human nutraceuticals and crude oil for fuels. Such a protein-rich co-product is a promising alternative to unsustainably sourced fishmeal in aquaculture diets. We report the first evaluation of co-product of the marine microalga Nannochloropsis oculata(N. oculata co-product) for replacing fishmeal in diets of Nile tilapia, a globally important aquaculture species. We conducted a nutrient digestibility experiment with N. oculata dried whole cells and N. oculata co-product, followed by an 84-day nutritional feeding experiment with N. oculata co-product. N. oculata co-product, more nutrient-dense …


The Importance Of Keeping The Big Ones: Harvest Slot Limits And Marine Protected Areas For The Management Of The Caribbean Spiny Lobster, Gayathiri Gnanalingam Jul 2018

The Importance Of Keeping The Big Ones: Harvest Slot Limits And Marine Protected Areas For The Management Of The Caribbean Spiny Lobster, Gayathiri Gnanalingam

Biological Sciences Theses & Dissertations

Fishing typically removes the oldest and/or largest individuals from populations undermining stability and reproductive success. Traditional fisheries management tools fail to protect these oldest and/or largest individuals, but two less conventional tools: marine protected areas (MPAs), and harvest slot limits have the potential to do so. Here I tested the possible use of these tools for the Caribbean spiny lobster, Panulirus argus, an iconic and economically valued species. After decades of intense fishing, the largest lobsters have largely been wiped out. The loss of the largest lobsters is significant as large lobsters have considerably greater reproductive potential than their …


Fisheries Bycatch Risk To Marine Megafauna Is Intensified In Lagrangian Coherent Structures, Kylie L. Scales, Elliot L. Hazen, Michael G. Jacox, Frederic Castruccio, Sara M. Maxwell, Rebecca L. Lewison, Steven J. Bograd Jul 2018

Fisheries Bycatch Risk To Marine Megafauna Is Intensified In Lagrangian Coherent Structures, Kylie L. Scales, Elliot L. Hazen, Michael G. Jacox, Frederic Castruccio, Sara M. Maxwell, Rebecca L. Lewison, Steven J. Bograd

Biological Sciences Faculty Publications

Incidental catch of nontarget species (bycatch) is a major barrier to ecological and economic sustainability in marine capture fisheries. Key to mitigating bycatch is an understanding of the habitat requirements of target and nontarget species and the influence of heterogeneity and variability in the dynamic marine environment. While patterns of overlap among marine capture fisheries and habitats of a taxonomically diverse range of marine vertebrates have been reported, a mechanistic understanding of the real-time physical drivers of bycatch events is lacking. Moving from describing patterns toward understanding processes, we apply a Lagrangian analysis to a high-resolution ocean model output to …


Ecological Neighborhoods As A Framework For Umbrella Species Selection, Erica F. Stuber, Joseph J. Fontaine May 2018

Ecological Neighborhoods As A Framework For Umbrella Species Selection, Erica F. Stuber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Umbrella species are typically chosen because they are expected to confer protection for other species assumed to have similar ecological requirements. Despite its popularity and substantial history, the value of the umbrella species concept has come into question because umbrella species chosen using heuristic methods, such as body or home range size, are not acting as adequate proxies for the metrics of interest: species richness or population abundance in a multi-species community for which protection is sought. How species associate with habitat across ecological scales has important implications for understanding population size and species richness, and therefore may be a …


Population Characteristics Of A Closed Northern Pike (Esox Lucius) Catch-And-Release Population In Minnesota, John Kempe May 2018

Population Characteristics Of A Closed Northern Pike (Esox Lucius) Catch-And-Release Population In Minnesota, John Kempe

Biology Graduate Theses

Literature regarding catch-and-release populations of Northern Pike are rare and provide a unique perspective on their population dynamics. Shingobee Lake is a 64- ha mesotrophic lake with a maximum depth of 12.2 m located in northern Minnesota. Northern Pike fishing has been catch-and-release only since 2005, and there are no public accesses on the lake. Annual ice-out trap-netting occurred from 2009-2017, and a sizable amount of the Northern Pike recaptured via trapnet or angling had been previously tagged (37-59%). The lack of exploitation and high tagging percentage provided a unique opportunity to study the population dynamics of Northern Pike. Shinogbee’s …


The Relationship Between Measures Of Annual Livestock Disturbance In Western Riparian Areas And Stream Conditions Important To Trout, Salmon, And Char, Lindsey M. Goss, Brett B. Roper Apr 2018

The Relationship Between Measures Of Annual Livestock Disturbance In Western Riparian Areas And Stream Conditions Important To Trout, Salmon, And Char, Lindsey M. Goss, Brett B. Roper

Watershed Sciences Faculty Publications

Managing livestock disturbance in riparian zones in a manner that provides economic returns to ranchers while protecting streams is an important aspect of rangeland management on public lands in the western United States. Attempts to balance economic and ecologic outcomes have been made more difficult due to the presence of several salmonid species that are protected under the Endangered Species Act. One approach to proper management of livestock use near streams has been to define the allowable limits of disturbance using 2 metrics, streambank alteration and stubble height. We evaluated 153 stream reaches within the Interior Columbia Basin to determine …


Big Fish, Big Data: Discussing The State Of Salmon And Improving King Salmon Regulation Through A Population Model, Creed Coram 18 Apr 2018

Big Fish, Big Data: Discussing The State Of Salmon And Improving King Salmon Regulation Through A Population Model, Creed Coram 18

Honor Scholar Theses

No abstract provided.


Assessing Trade-Offs In Large Marine Protected Areas, Tammy E. Davies, Graham Epstein, Stacy E. Aguilera, Cassandra M. Brooks, Michael Cox, Louisa S. Evans, Sara M. Maxwell, Mateja Nenadovic, Natalie C. Ban Apr 2018

Assessing Trade-Offs In Large Marine Protected Areas, Tammy E. Davies, Graham Epstein, Stacy E. Aguilera, Cassandra M. Brooks, Michael Cox, Louisa S. Evans, Sara M. Maxwell, Mateja Nenadovic, Natalie C. Ban

Biological Sciences Faculty Publications

Large marine protected areas (LMPAs) are increasingly being established and have a high profile in marine conservation. LMPAs are expected to achieve multiple objectives, and because of their size are postulated to avoid trade-offs that are common in smaller MPAs. However, evaluations across multiple outcomes are lacking. We used a systematic approach to code several social and ecological outcomes of 12 LMPAs. We found evidence of three types of trade-offs: trade-offs between different ecological resources (supply trade-offs); trade-offs between ecological resource conditions and the well-being of resource users (supply-demand trade-offs); and trade-offs between the well-being outcomes of different resource users …


Fishery Interaction Modeling Of Cetacean Bycatch In The California Drift Gillnet Fishery To Inform A Dynamic Ocean Management Tool, Nicholas B. Sisson Apr 2018

Fishery Interaction Modeling Of Cetacean Bycatch In The California Drift Gillnet Fishery To Inform A Dynamic Ocean Management Tool, Nicholas B. Sisson

Biological Sciences Theses & Dissertations

Understanding the drivers that lead to interaction between target species in a fishery and marine mammals is a critical aspect in efforts to reduce bycatch. In the California drift gillnet fishery static management approaches and gear changes have reduced bycatch but neither measure ascertains the underlying dynamics causing bycatch events. To avoid further potentially drastic measures such as hard caps, dynamic management approaches that consider the scales relevant to physical dynamics, animal movement and human use could be implemented. A key component to this approach is determining the factors that lead to fisheries interactions. Using 25 years (1990-2014) of National …


Synchrony — An Emergent Property Of Recreational Fisheries, Mark A. Kaemingk, Christopher J. Chizinski, Keith Hurley, Kevin L. Pope Mar 2018

Synchrony — An Emergent Property Of Recreational Fisheries, Mark A. Kaemingk, Christopher J. Chizinski, Keith Hurley, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. Recreational fisheries are traditionally managed at local scales, but more effective management could be achieved using a cross-scale approach. To do this, we must first understand how local processes scale up to influence landscape patterns between anglers and resources. We highlight how population-based synchrony methods, used in conjunction with a complex-adaptive-systems framework, can reveal emergent spatial properties within social-ecological systems such as recreational fisheries.

2. Herein, we quantified the level of spatial synchrony in angler behaviour, defined the relationship between angler synchrony and distance among waterbodies, and highlighted social-ecological attributes contributing to these patterns. We leveraged a 111 waterbody-year …


Reducing Dietary Protein In Pond Production Of Hybrid Striped Bass (Morone Chrysops × M. Saxatilis): Effects On Fish Performance And Water Quality Dynamics, Steven Rawles, Bartholomew Green, Matthew Mcentire, T. Gibson Gaylord, Frederic T. Barrows Feb 2018

Reducing Dietary Protein In Pond Production Of Hybrid Striped Bass (Morone Chrysops × M. Saxatilis): Effects On Fish Performance And Water Quality Dynamics, Steven Rawles, Bartholomew Green, Matthew Mcentire, T. Gibson Gaylord, Frederic T. Barrows

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In previous work, we demonstrated that diets containing 40% digestible protein (DP) (45% crude protein) and 18% lipid supplemented with Met and Lys resulted in superior performance and nutrient retentions in hybrid striped bass (HSB) compared to less energy-dense diets when rearing HSB at temperatures similar to the summer growing period of the Southern U.S. The current work was aimed at vetting previous results in pond production of market-size HSB at commercial stocking densities to assess impacts on fish production indices and water quality parameters. Diets were formulated to contain digestible protein levels ranging from 41% to 35% DP and …


California Rushes In—Keeping Water Instream For Fisheries Without Federal Law, Paul Stanton Kibel Feb 2018

California Rushes In—Keeping Water Instream For Fisheries Without Federal Law, Paul Stanton Kibel

William & Mary Environmental Law and Policy Review

No abstract provided.


Summary Of The Stock Structure Information Used For Determining Spatial Management Of The Index Species For The Scalefish Resources Of Northern Western Australia, Daniel J. Gaughan, Stephen J. Newman, Corey B. Wakefield Feb 2018

Summary Of The Stock Structure Information Used For Determining Spatial Management Of The Index Species For The Scalefish Resources Of Northern Western Australia, Daniel J. Gaughan, Stephen J. Newman, Corey B. Wakefield

WA Marine Stewardship Council report series

This paper was specifically developed in response to issues raised in an assessment of the Pilbara Trap Managed Fishery (PTMF) against the fishery sustainability standard of the Marine Stewardship Council (MSC).


Resource Assessment Report Western Australian Sea Cucumber Resource, Anthony M. Hart, D. V. Murphy, N Caputi, Alexander Hesp, E. A. Fisher Jan 2018

Resource Assessment Report Western Australian Sea Cucumber Resource, Anthony M. Hart, D. V. Murphy, N Caputi, Alexander Hesp, E. A. Fisher

WA Marine Stewardship Council report series

This document provides a cumulative description and assessment of the Sea Cucumber Resource and all of the fishing activities (i.e. fisheries / fishing sectors) affecting this resource in Western Australia (WA). The overall resource comprises two main species (sandfish Holothuria scabra and redfish Actinopyga echinites), and few minor species that inhabit the tropical shallow continental shelf waters of the North Coast Bioregion.


Resource Assessment Report Western Australian Octopus Resource, Anthony M. Hart, Daniel Murphy, Alastair Harry, E. A. Fisher Jan 2018

Resource Assessment Report Western Australian Octopus Resource, Anthony M. Hart, Daniel Murphy, Alastair Harry, E. A. Fisher

WA Marine Stewardship Council report series

This document provides a cumulative description and assessment of the Octopus Resource and all of the fishing activities (i.e. fisheries / fishing sectors) affecting this resource in Western Australia (WA). The overall resource essentially comprises a single species of octopus, Octopus aff. tetricus, which occurs in inshore waters to 70 m depth from Shark Bay to Esperance.


Growth Rate And Hatch Date Of Age-0 Fishes On Leech Lake, Minnesota Before Zebra Mussel Establishment, Kayla Morey, Emily Larson Jan 2018

Growth Rate And Hatch Date Of Age-0 Fishes On Leech Lake, Minnesota Before Zebra Mussel Establishment, Kayla Morey, Emily Larson

Journal of Earth and Life Science

The introduction of an invasive species to an ecosystem is considered a very severe environmental problem. Zebra Mussel veligers Dreissena polymorpha have recently been found in Leech Lake, Minnesota, and are likely going to have a large influence on this ecosystem. Zebra Mussels are filter-feeders that rely on phytoplankton and zooplankton as their main source of energy. A shift in populations of plankton due to Zebra Mussels may affect the growth rates of larval fish. Median hatch dates and growth rates were estimated from four age-0 fish species (Yellow Perch Perca flavescens, Walleye Sander vitreus, Smallmouth Bass Micropterus …


Thermal Tolerance Limits Of The Chinese Mystery Snail (Bellamya Chinensis): Implications For Management, Jessica L. Burnett, Kevin L. Pope, Alec Wong, Craig R. Allen, Danielle Haak, Bruce J. Stephen, Daniel R. Uden Jan 2018

Thermal Tolerance Limits Of The Chinese Mystery Snail (Bellamya Chinensis): Implications For Management, Jessica L. Burnett, Kevin L. Pope, Alec Wong, Craig R. Allen, Danielle Haak, Bruce J. Stephen, Daniel R. Uden

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The Chinese mystery snail, Bellamya chinensis (Gray, 1834) is a gastropod native to East Asia and is considered an invasive species in North America where its impacts on native species and ecosystems are not well understood. Scientific literature describing its biology and life history are sparse. Thermal tolerance limits, or the maximum and minimum temperature under which a species can survive, are key to identifying the potential geographical range of a species. The ability of managers to control invasive species is directly impacted by the thermal tolerance limits of a species. We attempted to identify the thermal tolerance limits of …


The Effect Of Size On Juvenile Green Sturgeon (Acipenser Medirostris) Behavior Near Water-Diversion Fish Screens, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue Jan 2018

The Effect Of Size On Juvenile Green Sturgeon (Acipenser Medirostris) Behavior Near Water-Diversion Fish Screens, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Anthropogenic water management projects and facilities that alter the local and regional hydrology of riverine environments greatly influence the behavior, physiology, and survival of native fishes. To mitigate for losses of native fishes at these structures, many are outfitted with fish-exclusion screens to reduce entrainment. The effect of fish size and age on behavior near fish screens, however, is largely unknown. Therefore, we tested two size classes of juvenile green sturgeon (Acipenser medirostris; small, early juveniles: 9.2 ± 0.2 cm fork length [FL], 6.9 ± 0.3 g; intermediate juveniles: 18.8 ± 0.2 cm FL, 36.9 ± 0.8 g) …


Resilience In Environmental Risk And Impact Assessment: Concepts And Measurement, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Kevin L. Pope, Dirac L. Twidwell Jr, Micro Bunschuh Jan 2018

Resilience In Environmental Risk And Impact Assessment: Concepts And Measurement, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Kevin L. Pope, Dirac L. Twidwell Jr, Micro Bunschuh

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Different resilience concepts have different assumptions about system dynamics, which has implications for resilience-based environmental risk and impact assessment. Engineering resilience (recovery) dominates in the risk assessment literature but this definition does not account for the possibility of ecosystems to exist in multiple regimes. In this paper we discuss resilience concepts and quantification methods. Specifically, we discuss when a system fails to show engineering resilience after disturbances, indicating a shift to a potentially undesired regime. We show quantification methods that can assess the stability of this new regime to inform managers about possibilities to transform the system to a more …


Agroecology For The Shrinking City, Dustin L. Herrmann, Wen-Ching Chuang, Kristen Schawrz, Timothy M. Bowles, Ahjond S. Garmestani, William D. Shuster, Tarsha Eason, Matthew E. Hopton, Craig R. Allen Jan 2018

Agroecology For The Shrinking City, Dustin L. Herrmann, Wen-Ching Chuang, Kristen Schawrz, Timothy M. Bowles, Ahjond S. Garmestani, William D. Shuster, Tarsha Eason, Matthew E. Hopton, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Many cities are experiencing long-term declines in population and economic activity. As a result, frameworks for urban sustainability need to address the unique challenges and opportunities of such shrinking cities. Shrinking, particularly in the U.S., has led to extensive vacant land. The abundance of vacant land reflects a loss of traditional urban amenities, economic opportunity, neighbors, businesses, and even basic city services and often occurs in neighborhoods with socially and economically vulnerable or underserved populations. However, vacant land also provides opportunities, including the space to invest in green infrastructure that can provide ecosystem services and support urban sustainability. Achieving desirable …


Conservation Limnogeology And Benthic Habitat Mapping In Central Lake Tanganyika (Tanzania), Joseph S. Lucas Jan 2018

Conservation Limnogeology And Benthic Habitat Mapping In Central Lake Tanganyika (Tanzania), Joseph S. Lucas

Theses and Dissertations--Earth and Environmental Sciences

Small scale protected zones are valuable for helping the health and productivity of fisheries at Lake Tanganyika (East Africa). Spatial placement of protected areas relies on accurate maps of benthic habitats, consisting of detailed bathymetry data and information on lake-floor substrates. This information is unknown for most of Lake Tanganyika. Fish diversity is known to correlate with rocky substrates in ≤ 30 m water depth, which provide spawning grounds for littoral and pelagic species. These benthic habitats form important targets for protected areas, if they can be precisely located.

At the NMVA, echosounding defined the position of the 30-m isobath …


Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson Jan 2018

Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson

Journal of Earth and Life Science

Within Voyageurs National Park, spiny water flea Bythotrephes longimanus has reduced Lake Kabetogama and Rainy Lake native zooplankton biomass during summer peak by 40-60%. Subsequently, planktivorous age-0 Yellow Perch Perca flavescens growth has decreased. A possible trophic cascade may influence predatory fish growth rates like that of age-0 Walleye Sander vitreus. Using seine net and electrofishing data, age-0 Walleye growth rates were modeled as a linear function of growing degree days (GDD) and the slope was compared between pre- and post-spiny water flea establishment. Nearby Lake Vermilion, assumed to have been unaffected by spiny water flea until 2015 and …


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 …


Opportunities And Challenges For Big Data Ornithology, Frank A. La Sorte, Christopher A. Lepczyk, Jessica L. Burnett, Allen H. Hurlbert, Morgan W. Tingley, Benjamin Zuckerberg Jan 2018

Opportunities And Challenges For Big Data Ornithology, Frank A. La Sorte, Christopher A. Lepczyk, Jessica L. Burnett, Allen H. Hurlbert, Morgan W. Tingley, Benjamin Zuckerberg

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Recent advancements in information technology and data acquisition have created both new research opportunities and new challenges for using big data in ornithology. We provide an overview of the past, present, and future of big data in ornithology, and explore the rewards and risks associated with their application. Structured data resources (e.g., North American Breeding Bird Survey) continue to play an important role in advancing our understanding of bird population ecology, and the recent advent of semistructured (e.g., eBird) and unstructured (e.g., weather surveillance radar) big data resources has promoted the development of new empirical perspectives that are generating novel …


A Framework For Tracing Social–Ecological Trajectories And Traps In Intensive Agricultural Landscapes, Daniel R. Uden, Craig R. Allen, Francisco Munoz-Arriola, Gengxin Ou, Nancy Shank Jan 2018

A Framework For Tracing Social–Ecological Trajectories And Traps In Intensive Agricultural Landscapes, Daniel R. Uden, Craig R. Allen, Francisco Munoz-Arriola, Gengxin Ou, Nancy Shank

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Charting trajectories toward sustainable agricultural development is an important goal at the food–energy–water–ecosystem services (FEWES) nexus of agricultural landscapes. Social–ecological adaptation and transformation are two broad strategies for adjusting and resetting the trajectories of productive FEWES nexuses toward sustainable futures. In some cases, financial incentives, technological innovations, and/or subsidies associated with the short-term optimization of a small number of resources create and strengthen unsustainable feedbacks between social and ecological entities at the FEWES nexus. These feedbacks form the basis of rigidity traps, which impede adaptation and transformation by locking FEWES nexuses into unsustainable trajectories characterized by control, stability, and efficiency, …