Aquaculture and Fisheries Commons^™

Reproductive Characteristics Of Landlocked Fall Chinook Salmon From Lake Oahe, South Dakota, Kelsen L. Young, Michael E. Barnes, Jeremy L. Kientz

The Prairie Naturalist

Lake Oahe, South Dakota, USA, landlocked fall Chinook salmon (Oncorhynchus tshawytscha) reproductive characteristics were examined over a 27 year period, from 1988 to 2015. Mean total lengths of spawning females ranged from 665 mm (1995) to 812 mm (2015) with considerable year-to-year variation. Post-spawn female weights varied, ranging from 2.02 kg (2000) to 5.55 kg (2015), with an overall mean of 3.04 kg. Fecundity peaked at 4,555 eggs per female in 2003, which was just 3 years after a low of 2,011 eggs per female in 2000. Relative fecundity based on female weight was greatest at 1,211 eggs/kg …

Panarchy Use In Environmental Science For Risk And Resilience Planning, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Lance H. Gunderson, Igor Linkov

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Environmental sciences have an important role in informing sustainable management of built environments by providing insights about the drivers and potentially negative impacts of global environmental change. Here, we discuss panarchy theory, a multi-scale hierarchical concept that accounts for the dynamism of complex socio-ecological systems, especially for those systems with strong cross-scale feedbacks. The idea of panarchy underlies much of system resilience, focusing on how systems respond to known and unknown threats. Panarchy theory can provide a framework for qualitative and quantitative research and application in the environmental sciences, which can in turn inform the ongoing efforts in sociotechnical resilience …

Molecular Analysis Confirming The Introduction Of Nile Crocodiles, Crocodylus Niloticus Laurenti 1768 (Crocodylidae), In Southern Florida, With An Assessment Of Potential For Establishment, Spread, And Impacts., Michael R. Rochford, Kenneth L. Krysko, Frank J. Mazzotti, Matthew W. Shirley, Mark W. Parry, Joseph A. Wasilewski, Jeffrey S. Beauchamp, Christpher R. Gillette, Edward F. Metzger Iii, Michiko A. Squires, Louis A. Somma

Papers in Herpetology

The state of Florida, USA, has more introduced herpetofauna than any other governmental region on Earth. Four species of nonnative crocodilians have been introduced to Florida (all since 1960), one of which is established. Between 2000–2014 we field-collected three nonnative crocodilians in Miami-Dade County, Florida, and one in Hendry County, Florida. We used DNA barcoding and molecular phylogenetics to determine species identification and native range origin. Also, we described diet, movement, and growth for one crocodile. Our molecular analyses illustrated that two of the crocodiles we collected are most closely related to Nile Crocodiles (Crocodylus niloticus) from South Africa, suggesting …

Low-Intensity, Stocker-Based Channel Catfish Culture, Bartholomew W. Green, Carole R. Engle, Rebecca Lochmann, Harold Phillips

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

Low-intensity production of Channel Catfish Ictalurus punctatus is characterized by low stocking rates, low installed aeration capacity, and no automated dissolved oxygen monitoring. Two studies conducted in nine 0.25-acre ponds quantified production characteristics of stocker Channel Catfish stocked for low-intensity food-fish production in single- or multiple-batch culture. In the multiple-batch study, 0.5-lb stockers (carryover fish) were stocked at 4,500 fish/acre and 0.044-lb fingerlings at 6,000 fish/acre. Stockers were grown to mean individual weights of 1.25, 1.75, or 2.25 lb. In the single-batch study, 0.5-lb stockers were stocked at 3,500, 4,500, and 5,500 fish/acre. All fish were fed a feed containing …

Bats Serves As Nebraska's Natural Pest Control Agents, Michael Whitby, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

You don't notice them flying in the night sky as you drive home, or in the trees above you as you walk your dog or under the bark of the dead tree at your fishing hole, but bats are everywhere in Nebraska. In fact, there are 13 species of bats inhabiting our state. They exhibit a wide variety of shapes, sizes and colors. Some migrate to unknown locations each winter. others stay in Nebraska and hibernate in caves, mines and occasionally homes. You probably won't notice them unless you happen to catch a glimpse of one eating insects under a …

Tiger Salamanders Disappearing In Region, Dennis M. Ferraro

School of Biological Sciences: Faculty Publications

"Where have all the salamanders gone?" 'This is a question I have been increasingly asked over the past five to six years from area residents. It seems we are observing a dramatic population decline of the western barred tiger salamander in parts of Southeast Nebraska. The western barred tiger salamander (Ambystoma mavortium) is one of only two salamanders in Nebraska. Over the past two years, none have been found in southeast Nebraska.

Salamanders, like all amphibians, are excellent indicator species. In many cases they act like the iconic canary in the mine shaft, telling us when to run …

Hepatic Transcriptomic And Metabolic Responses Of Hybrid Striped Bass (Morone Saxatilis × Morone Chrysops) To Acute And Chronic Hypoxic Insult, Benjamin H. Beck, S. Adam Fuller, Chao Li, Bartholomew W. Green, Honggang Zhao, Steven D. Rawles, Carl D. Webster, Eric Peatman

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

Striped bass (Morone saxatilis), white bass (Morone chrysops), and their hybrid are an important group of fish prized for recreational angling in the United States, and there and abroad as a high-value farmed fish. Regardless of habitat, it is not uncommon for fish of the genus Morone to encounter and cope with conditions of scarce oxygen availability. Previously, we determined that hybrid striped bass reared under conditions of chronic hypoxia exhibited reduced feed intake, lower lipid and nutrient retention, and poor growth. To better understand the molecular mechanisms governing these phenotypes, in the present study, we …

Hypoxia Affects Performance Traits And Body Composition Of Juvenile Hybrid Striped Bass (Morone Chrysops X M. Saxatilis), Bartholomew W. Green, Steven D. Rawles, Sidney A. Fuller, Benjamin H. Beck, Matthew E. Mcentire

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

Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0%, and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole-body protein content, whole body compositional indices and nutrient …

Early Life History Of Three Pelagic-Spawning Minnows Macrhybopsis Spp. In The Lower Missouri River, T. A. Starks, M. L. Miller, J. M. Long

US Army Corps of Engineers

Life-history characteristics of age-0 sturgeon chub Macrhybopsis gelida, shoal chub Macrhybopsis hyostoma and sicklefin chub Macrhybopsis meeki were compared using several methods. All Macrhybopsis species consumed mostly midge pupae, but M. meeki had the most general diet (Levins’ index, B=0⋅22) compared with M. hyostoma (B=0⋅02) and M. gelida (B=0⋅09). Morisita’s diet overlap index among species pairs ranged from 0⋅62 to 0⋅97 and was highest between M. hyostoma and M. gelida. Daily ages estimated from lapilli otoliths for each species ranged from 15 to 43 days for M. gelida, 19 to 44 for …

Transformative Environmental Governance, Brian C. Chaffin, Ahjond Garmestani, Lance Gunderson, Melinda Harm Benson, David G. Angeler, Craig Anthony (Tony) Arnold, Barbara Cosens, Robin Kundis Craig, J.B. B. Ruhl, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Transformative governance is an approach to environmental governance that has the capacity to respond to, manage, and trigger regime shifts in coupled social-ecological systems (SESs) at multiple scales. The goal of transformative governance is to actively shift degraded SESs to alternative, more desirable, or more functional regimes by altering the structures and processes that define the system. Transformative governance is rooted in ecological theories to explain cross-scale dynamics in complex systems, as well as social theories of change, innovation, and technological transformation. Similar to adaptive governance, transformative governance involves a broad set of governance components, but requires additional capacity to …

Potential Population And Assemblage Influences Of Non-Native Trout On Native Nongame Fish In Nebraska Headwater Streams, Kelly C. Turek, Mark A. Pegg, Kevin L. Pope, Steve Schainost

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in …

Using Standardized Fishery Data To Inform Rehabilitation Efforts, Jonathan J. Spurgeon, Nathaniel T. Stewart, Mark A. Pegg, Kevin L. Pope, Mark T. Porath

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Lakes and reservoirs progress through an aging process often accelerated by human activities, resulting in degradation or loss of ecosystem services. Resource managers thus attempt to slow or reverse the negative effects of aging using a myriad of rehabilitation strategies. Sustained monitoring programs to assess the efficacy of rehabilitation strategies are often limited; however, long-term standardized fishery surveys may be a valuable data source from which to begin evaluation.We present 3 case studies using standardized fishery survey data to assess rehabilitation efforts stemming from the Nebraska Aquatic Habitat Plan, a large-scale program with the mission to rehabilitate waterbodies within the …

Deathcore, Creativity, And Scientific Thinking, David G. Angeler, Shana M. Sundstrom, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Background Major scientific breakthroughs are generally the result of materializing creative ideas, the result of an inductive process that sometimes spontaneously and unexpectedly generates a link between thoughts and/or objects that did not exist before. Creativity is the cornerstone of scientific thinking, but scientists in academia are judged by metrics of quantification that often leave little room for creative thinking. In many scientific fields, reductionist approaches are rewarded and new ideas viewed skeptically. As a result, scientific inquiry is often confined to narrow but safe disciplinary ivory towers, effectively preventing profoundly creative explorations that could yield unexpected benefits.

This paper …

Genetic Correlates Of Individual Differences In Sleep Behavior Of Free-Living Great Tits (Parus Major), Erica F. Stuber, Christine Baumgartner, Niels J. Dingemanse, Bart Kempenaers, Jakob C. Mueller

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Within populations, free-living birds display considerable variation in observable sleep behaviors, reflecting dynamic interactions between individuals and their environment. Genes are expected to contribute to repeatable between-individual differences in sleep behaviors, which may be associated with individual fitness. We identified and genotyped polymorphisms in nine candidate genes for sleep, and measured five repeatable sleep behaviors in free-living great tits (Parus major), partly replicating a previous study in blue tits (Cyanistes caeruleus). Microsatellites in the CLOCK and NPAS2 clock genes exhibited an association with sleep duration relative to night length, and morning latency to exit the nest …

Factors Influencing Recruitment Of Walleye And White Bass To Three Distinct Early Ontogenetic Stages, Jason A. Deboer, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; …

Landscape Context Influences Nest Survival In A Midwest Grassland, Victoria L. Simonsen, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Although the management and restoration of habitat is the key method to conserve species of interest, local habitat management often fails to elicit desired responses in populations. Landscape features beyond the local habitat scale affect the population dynamics of ring-necked pheasants (Phasianus colchicus), but the mechanism behind this response is unknown. One possibility is that nest survival, which is primarily reduced by nest predation, is regulating pheasant responses to the landscape. We investigated the extent to which land use affected nest survival by studying 202 artificial nests on 12 Conservation Reserve Program (CRP) fields in Nebraska, USA with …

Management Applications Of Discontinuity Theory, David G. Angeler, Craig R. Allen, Chris Barichievy, Tarsha Eason, Ahjond S. Garmestani, Nicholas A.J. Graham, Dean Granholm, Lance H. Gunderson, Melinda Knutson, Kristy L. Nash, R. John Nelson, Magnus Nystrom, Trisha L. Spanbauer, Craig A. Stow, Shana M. Sundstrom

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. Human impacts on the environment are multifaceted and can occur across distinct spatiotemporal scales. Ecological responses to environmental change are therefore difficult to predict, and entail large degrees of uncertainty. Such uncertainty requires robust tools for management to sustain ecosystem goods and services and maintain resilient ecosystems.

2. We propose an approach based on discontinuity theory that accounts for patterns and processes at distinct spatial and temporal scales, an inherent property of ecological systems. Discontinuity theory has not been applied in natural resource management and could therefore improve ecosystem management because it explicitly accounts for ecological complexity.

3. Synthesis …

Quantifying Spatial Resilience, Craig R. Allen, David G. Angeler, Graeme S. Cumming, Carl Folke, Dirac L. Twidwell, Daniel R. Uden

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. Anthropogenic stressors affect the ecosystems upon which humanity relies. In some cases when resilience is exceeded, relatively small linear changes in stressors can cause relatively abrupt and nonlinear changes in ecosystems.

2. Ecological regime shifts occur when resilience is exceeded and ecosystems enter a new local equilibrium that differs in its structure and function from the previous state. Ecological resilience, the amount of disturbance that a system can withstand before it shifts into an alternative stability domain, is an important framework for understanding and managing ecological systems subject to collapse and reorganization.

3. Recently, interest in the influence of …

Avoiding Decline: Fostering Resilience And Sustainability In Midsize Cities, Craig R. Allen, Hannah E. Birge, Shannon L. Bartelt-Hunt, Rebecca Bevans, Jessica L. Burnett, Barbara A. Cosens, Ximing Cai, Ahjond S. Garmestani, Igor Linkov, Elizabeth A. Scott, Mark D. Solomon, Daniel R. Uden

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Eighty-five percent of United States citizens live in urban areas. However, research surrounding the resilience and sustainability of complex urban systems focuses largely on coastal megacities (>1 million people). Midsize cities differ from their larger counterparts due to tight urban-rural feedbacks with their immediate natural environments that result from heavy reliance and close management of local ecosystem services. They also may be less path-dependent than larger cities due to shorter average connection length among system components, contributing to higher responsiveness among social, infrastructural, and ecological feedbacks. These distinct midsize city features call for a framework that organizes information and …

Adaptive Management For Soil Ecosystem Services, Hannah E. Birge, Rebecca A. Bevans, Craig R. Allen, David G. Angeler, Sara G. Baer, Diana H. Wall Colorado State University

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

No abstract provided.

The Influence Of A Severe Reservoir Drawdown On Springtime Zooplankton And Larval Fish Assemblages In Red Willow Reservoir, Nebraska, Jason A. Deboer, Christa M. Webber, Taylor A. Dixon, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Reservoirs can be dynamic systems, often prone to unpredictable and extreme waterlevel fluctuations, and can be environments where survival is difficult for zooplankton and larval fish. Although numerous studies have examined the effects of extreme reservoir drawdown on water quality, few have examined extreme drawdown on both abiotic and biotic characteristics. A fissure in the dam at Red Willow Reservoir in southwest Nebraska necessitated an extreme drawdown; the water level was lowered more than 6 m during a two-month period, reducing reservoir volume by 76%. During the subsequent low-water period (i.e., post-drawdown), spring sampling (April-June) showed dissolved oxygen concentration was …

Fishing For Ecosystem Services, Kevin L. Pope, Mark A. Pegg, Nicholas W. Cole, Stephen F. Siddons, Alexis D. Fedele, Brian S. Harmon, Ryan L. Ruskamp, Dylan R. Turner, Caleb C. Uerling

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystembased management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, …

Letter Resisting Resilience Theory: Aresponse To Connelland Ghedini, Shana M. Sundstrom, Craig R. Allen, Lance H. Gunderson

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

ConnellandGhedini [1] arguethatecolo- gistsareprimarily [1TD$DIF]concernedwithcommu- nitychangeandtendtoignoreprocesses liketrophiccompensationthatcontribute to communityorsystem-levelstability. Resilience,theyclaim,isthestudyof change,andresearchersshouldspend moretimestudyingstabilizingprocesses to betterpredictthetypesofchanges documentedbyecologistswhostudyresil- ience [2,3]. Thebulkoftheirpaper addressesresilienceandrelatedconcepts to contextualizeresistancetochange,but theirargumentsarediminishedbecause theauthorsfailtoexplicitlyplacetheirwork withintherangeofresilienceconceptsthat haveproliferatedacrossacademicdisci- plines.Moreimportantly,thepaperfurthers confusionregardingcoreecologicalresil- ienceconcepts.Withinthedisciplineof ecology,resilienceconceptshavebeen developedinafundamentallycohesive way [4]. Understandingtheresilienceof complexsystemsofhumansandnature duringthistimeofrapidglobalchangeis importantandthemisuseorcasualuseof conceptswithspecific meaningismore thansimplyatrivialpointofcontention;it potentiallyobscuresprocessesandprop- ertiesthathavedirectrelevancetohuman- ity'sinteractionwiththeenvironment.

Body Size Distributions Signal A Regime Shift In A Lake Ecosystem, Trisha L. Spanbauer, Craig R. Allen, David G. Angeler, Tarsha Eason, Sherilyn C. Fritz, Ahjond S. Garmestani, Kirsty L. Nash, Jeffery R. Stone, Craig A. Stow, Shana M. Sundstrom

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of …

Adaptive Management For Ecosystem Services, Hannah E. Birgé, Craig R. Allen, Ahjond S. Garmestani, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Management of natural resources for the production of ecosystem services, which are vital for human well-being, is necessary even when there is uncertainty regarding system response to management action. This uncertainty is the result of incomplete controllability, complex internal feedbacks, and nonlinearity that often interferes with desired management outcomes, and insufficient understanding of nature and people. Adaptive management was developed to reduce such uncertainty. We present a framework for the application of adaptive management for ecosystem services that explicitly accounts for cross-scale tradeoffs in the production of ecosystem services. Our framework focuses on identifying key spatiotemporal scales (plot, patch, ecosystem, …

Influence Of Anglers’ Specializations On Catch, Harvest, And Bycatch Of Targeted Taxa, Kevin L. Pope, Christopher J. Chizinski, Christopher L. Wiley, Dustin R. Martin

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Fishery managers often use catch per unit effort (CPUE) of a given taxon derived from a group of anglers,those that sought said taxon, to evaluate fishery objectives because managers assume CPUE for this group of anglers is most sensitive to changes in fish taxon density. Further, likelihood of harvest may differ for sought and non-sought taxa if taxon sought is a defining characteristic of anglers’ attitude toward harvest.We predicted that taxon-specific catch across parties and reservoirs would be influenced by targeted taxon after controlling for number of anglers in a party and time spent fishing (combine to quantify fishing effort …

Biological Invasions, Ecological Resilience And Adaptive Governance, Brian C. Chaffin, Ahjond S. Garmestani, David G. Angeler, Dustin L. Herrmann, Craig A. Stow, Magnus Nystrom, Jan Sendzimir, Matthew E. Hopton, Jurek Kolasa, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

In a world of increasing interconnections in global trade as well as rapid change in climate and land cover, the accelerating introduction and spread of invasive species is a critical concern due to associated negative social and ecological impacts, both real and perceived. Much of the societal response to invasive species to date has been associated with negative economic consequences of invasions. This response has shaped a war-like approach to addressing invasions, one with an agenda of eradications and intense ecological restoration efforts towards prior or more desirable ecological regimes. This trajectory often ignores the concept of ecological resilience and …

Fishing Diseased Abalone To Promote Yield And Conservation, Tal Ben-Horin, Kevin D. Lafferty, Gorka Bidegain, Hunter S. Lenihan

United States Geological Survey: Staff Publications

Past theoretical models suggest fishing disease-impacted stocks can reduce parasite transmission, but this is a good management strategy only when the exploitation required to reduce transmission does not overfish the stock. We applied this concept to a red abalone fishery so impacted by an infectious disease (withering syndrome) that stock densities plummeted and managers closed the fishery. In addition to the non-selective fishing strategy considered by past disease- fishing models, we modelled targeting (culling) infected individuals,which is plausible in red abalone because modern diagnostic tools can determine infection without harming landed abalone and the diagnostic cost is minor relative to …