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Articles 1411 - 1440 of 3773

Full-Text Articles in Population Biology

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren Jan 2020

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …


Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt Jan 2020

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …


Evaluation Of Space Use And Movement By Wild Turkey (Meleagris Gallopavo) During Extreme Climatic Disturbances And Annual Phenological States, David J. Moscicki Jan 2020

Evaluation Of Space Use And Movement By Wild Turkey (Meleagris Gallopavo) During Extreme Climatic Disturbances And Annual Phenological States, David J. Moscicki

LSU Master's Theses

Space use is driven by both intrinsic and extrinsic factors across space and time. Meaning a species demography and habitat requirements may vary across landscapes. Recent studies on wild turkeys (Meleagris gallopavo spp., hereafter turkey) have shown both direct and indirect demographic impacts of climatically driven events on turkey populations. Similarly, there is an abundance of information documenting turkey demographic parameters and space use, but few studies have addressed breeding phenology in great detail. We evaluated the impact on space use and movement patterns of Eastern wild turkeys (M. g. silvestris; n = 20) and Rio Grande wild …


Proceedings Of The Fifteenth North American Crane Workshop, Jane E. Austin, Richard P. Urbanek, Megan E. Brown Jan 2020

Proceedings Of The Fifteenth North American Crane Workshop, Jane E. Austin, Richard P. Urbanek, Megan E. Brown

Proceedings of the North American Crane Workshop

Proceedings of the Fifteenth North American Crane Workshop (2020) edited by Jane E. Austin, Richard P. Urbanek, and Megan E. Brown.


Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight Jan 2020

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

United States Department of Agriculture Wildlife Services: Staff Publications

  1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
  2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …


The Effectiveness Of Long-Distance Translocation Of Eastern Diamondback Rattlesnakes (Crotalus Adamanteus), Allison Grace Kelley Jan 2020

The Effectiveness Of Long-Distance Translocation Of Eastern Diamondback Rattlesnakes (Crotalus Adamanteus), Allison Grace Kelley

Theses, Dissertations and Capstones

Translocations have the potential to aim conservation efforts as well as to reduce mortality caused by human activities. Eastern diamondback rattlesnakes (Crotalus adamanteus, EDB) have a limited ability to adapt to habitat loss and fragmentation due to the species’ slow life history and minimal dispersal ability. Because they are a venomous species, they are viewed as nuisance animals and are often killed on sight. We translocated a cohort of EDBs to investigate the potential of using translocations as a conservation and mitigation tool for this species. In July 2018, we translocated twelve adult eastern diamondback rattlesnakes from Parris …


Impact Of Nacl Tolerance On The Stress Physiology And Fitness Of Larval Wood Frogs (Rana Sylvatica), Grascen Shidemantle, Nicholas Buss, Jessica Hua Jan 2020

Impact Of Nacl Tolerance On The Stress Physiology And Fitness Of Larval Wood Frogs (Rana Sylvatica), Grascen Shidemantle, Nicholas Buss, Jessica Hua

Biological Sciences Student Scholarship

No abstract provided.


Habitat Associations And Co-Occurrence Patterns Of Two Estuarine-Dependent Predatory Fishes, Mariah C. Livernois, Sean P. Powers, Mark A. Albins, John F. Mareska Jan 2020

Habitat Associations And Co-Occurrence Patterns Of Two Estuarine-Dependent Predatory Fishes, Mariah C. Livernois, Sean P. Powers, Mark A. Albins, John F. Mareska

University Faculty and Staff Publications

Estuarine-dependent fishes experience a wide range of environmental conditions, and most species exhibit distinct associations with particular habitats. However, similar species or multiple conspecifics often overlap spatiotemporally, which can result in ecological interactions that have consequences for behaviors that can shape the structure and function of ecosystems. We used a long-term gill-net data set (2001–2015) to investigate the habitat associations and cooccurrence patterns of two estuarine-dependent predatory fishes, Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus, in coastal Alabama, USA. Both species were associated with similar environmental conditions, primarily low dissolved oxygen and low salinity, especially when temperature was …


Estimates Of Red Drum Mortality Via Acoustic Telemetry, T. Reid Nelson, Sean P. Powers Jan 2020

Estimates Of Red Drum Mortality Via Acoustic Telemetry, T. Reid Nelson, Sean P. Powers

University Faculty and Staff Publications

Subadult (age < 3) Red Drum Sciaenops ocellatus support a valuable recreational fishery, and mortality estimates for young Red Drum are needed for proper management. To obtain these estimates, age-1 and age-2 Red Drum were implanted with acoustic transmitters and external Floy tags in two coastal Alabama rivers (Fowl and Dog rivers). Fates of tagged fish were inferred from stationary receiver detections and active relocations over 1 year. These fates were used in a Bayesian multistate model to estimate instantaneous monthly and annual mortality and emigration rates for each river and overall from both rivers. Instantaneous monthly fishing mortality (F) ranged from 0.001 to 0.112 (annual F = 0.414) in Dog River, from 0.001 to 0.126 in Fowl River (annual F = 0.309), and was 0.001–0.054 (annual F = 0.337) overall. Instantaneous monthly natural mortality (M) ranged from 0.001 to 0.002 (annual M= 0.069) in Dog River, from 0.001 to 0.036 (annual M= 0.178) in Fowl River, and from 0.001 to 0.017 (annual M= 0.090) overall. The overall annual estimate of instantaneous total mortality (Z) was 0.435. The median escapement percentage was estimated at 36.3% (95% posterior credible interval = 19.5–56.0%) using M and Z from the overall model. Unfortunately, the error on this estimate was large and inconclusive as to whether the 30% escapement goal for juvenile Red Drum to the adult population from Dog and Fowl rivers is being met. Monthly residency estimates were typically greater than 0.90, and overall annual residency was estimated at 0.716. Fishing mortality estimates from the current study are higher than recent catch curve estimates that did not include young Red Drum. These results demonstrate that young Red Drum need to be accounted for when generating mortality estimates and provide needed data for the Red Drum recreational fishery.


Landscape Genetics Of Salamander Populations At Mammoth Cave National Park, Jackson Resser Jan 2020

Landscape Genetics Of Salamander Populations At Mammoth Cave National Park, Jackson Resser

Mahurin Honors College Capstone Experience/Thesis Projects

Habitat connectivity affects the distribution of genetic diversity among populations by influencing the movements of individuals and the resulting pattern of gene flow across landscapes. It has become evident that amphibians are experiencing a period of worldwide population declines brought about by environmental change. An understanding of the effects of habitat structure on landscape connectivity is important for developing effective amphibian conservation strategies. The purpose of this study is to investigate the effect of landscape characteristics on gene flow and population structure of the marbled salamander (Ambystoma opacum) in Mammoth Cave National Park, Kentucky, USA. Salamander larvae were …


Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler Jan 2020

Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler

United States Department of Agriculture Wildlife Services: Staff Publications

In 2015, the mcr-1 gene was discovered in Escherichia coli in domestic swine in China that conferred resistance to colistin, an antibiotic of last resort used in treating multi-drug resistant bacterial infections in humans. Since then, mcr-1 was found in other human and animal populations, including wild gulls. Because gulls could disseminate the mcr-1 gene, we conducted an experiment to assess whether gulls are readily colonized with mcr-1 positive E. coli, their shedding patterns, transmission among conspecifics, and environmental deposition. Shedding of mcr-1 E. coli by small gull flocks followed a lognormal curve and gulls shed one strain >101 …


Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr Jan 2020

Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to

their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these …


Control Or Eradication: Problems In The Management Of Invasive Birds, Michael L. Avery, Chris J. Feare Jan 2020

Control Or Eradication: Problems In The Management Of Invasive Birds, Michael L. Avery, Chris J. Feare

United States Department of Agriculture Wildlife Services: Staff Publications

Humans have captured, transported and intentionally released wild birds for centuries (Blackburn et al., 2009). Motivations for such purposeful introductions include food (West and Zhou, 2007), religion (Agoramoorthy and Hsu, 2007), sport (McDowall, 1994), biocontrol (Bennett and Hughes, 1959; Kurdila, 1995) and aesthetics (Ryan, 1906; Thomson, 1922). Many purposeful bird introductions were the work of acclimatization societies, particularly in North America, New Zealand and Australia. These societies were formed in the 19th century by European settlers to transport bird species from their homelands in efforts to establish them in the newly settled regions (Thomson, 1922; Dunlap, 1997). As a result …


Bio-Economic Outcomes Under Alternative Management Strategies With Human Choice And Behavior: Modeling Tautog And Anglers' Preferences, Eric T. Schultz, Zhenshan Chen, Pengfei Liu, Stephen Swallow, Jacob M. Kasper Jan 2020

Bio-Economic Outcomes Under Alternative Management Strategies With Human Choice And Behavior: Modeling Tautog And Anglers' Preferences, Eric T. Schultz, Zhenshan Chen, Pengfei Liu, Stephen Swallow, Jacob M. Kasper

EEB Articles

Key findings

  • There was relatively strong support for slot limits, and roughly comparable support for status quo management, among anglers fishing for Tautog in Long Island Sound.
  • Respondents were not in favor of a total moratorium on fishing for Tautog.
  • Providing survey respondents information on how different management scenarios will affect fishing in the future had little detectable impact on fishing preferences.
  • Respondents expected to fish less in the future if a wide slot limit is imposed or if status quo management is maintained, but expected no change in effort if a narrow slot limit is imposed.
  • Changes in regulations …


Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea Jan 2020

Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea

Journal of Earth and Life Science

In the midwestern USA, water clarity has decreased in shallow lakes as a result of large populations of Fathead Minnow Pimephales promelas and agriculture that impact the life that depend on shallow habitats, such as waterfowl, fish, and aquatic plants. Northern Pike Esox lucius and Yellow Perch Perca flavescens were stocked in a few lakes in attempt to create a tropic cascade and reduce populations of nuisance Fathead Minnows. Northern Pike were stocked as fry and Yellow Perch were stocked as adults either pre-spawn or post-spawn. Lake managers hypothesized adult Yellow Perch would spawn and the age-0 Perch would feed …


Spring Field Report, March-May 2020, W. Ross Silcock Jan 2020

Spring Field Report, March-May 2020, W. Ross Silcock

Nebraska Bird Review

Although there were numerous early arrival dates, most were in the range of historically earliest expected dates; notable, however, was a lone record-early Whiterumped Sandpiper, nicely photographed. Record late by a month was a juvenile Redtailed (Harlan’s) Hawk, also confirmed by photo. Perhaps most prominent this spring were the large numbers of several species. Most eye-popping were record spring totals of 22 Glossy Ibises, 11 Yellow-bellied Flycatchers, 14 Veeries, including five in the Panhandle, 48 Gray-cheeked Thrushes, 20 Bay-breasted Warblers, not long ago a rare bird in spring, 45 Golden-winged Warblers and 27 Canada Warblers, both of which were about …


The Nebraska Bird Review, Volume 88 March 2020 Number 1 Jan 2020

The Nebraska Bird Review, Volume 88 March 2020 Number 1

Nebraska Bird Review

Winter Field Report, Dec. 2019 - Feb. 2020, by W. Ross Silcock …2

2019-2020 Christmas Bird Counts …18, 27-41

Annual Color Photo Section …19-26

Annual Treasurer's Report for 2019, by Jan Johnson …42

Subscription and Organization Information …43


Table Of Contents Jan 2020

Table Of Contents

Human–Wildlife Interactions

This is the table of contents.


Distribution And Reproduction By The Purple Gallinule (Porphyrio Martinica) In Arkansas, C. Renn Tumlison, Terry L. Tumlison, Tamzen T. Bryant Jan 2020

Distribution And Reproduction By The Purple Gallinule (Porphyrio Martinica) In Arkansas, C. Renn Tumlison, Terry L. Tumlison, Tamzen T. Bryant

Journal of the Arkansas Academy of Science

The Purple Gallinule (Porphyrio martinica) is a rare bird in Arkansas, and its populations likely have declined due to loss of marshy areas with emergent vegetation. By use of online sources for citizen science combined with a field study, we elucidate the current distribution of this bird in Arkansas, and document characteristics of reproduction and development. Purple Gallinules arrive in Arkansas as early as April and remain to late October. Nesting occurs from early May into July, and nests may represent second broods. Ontogenetic changes in hatchlings are described.


Finding Fishers: Determining The Distribution Of A Rare Forest Mesocarnivore In The Northern Rocky Mountains, Jessica M. Krohner Jan 2020

Finding Fishers: Determining The Distribution Of A Rare Forest Mesocarnivore In The Northern Rocky Mountains, Jessica M. Krohner

Graduate Student Theses, Dissertations, & Professional Papers

The Northern Rocky Mountain fisher population (Pekania pennanti), is classified as a Species of Greatest Conservation Need and is of special concern to state, federal, and tribal entities. In this thesis, we present methods to effectively survey fishers across the northern Rockies of Idaho and Montana, and provide estimates of fisher distribution at a population range-wide scale through occupancy analyses. We also assess factors that influence fisher occurrence through covariate analyses and identify core fisher habitat in the northern Rockies through spatial occupancy modeling. By sampling broadly across the landscape, we provide baseline distributional data for comparison against …


Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan Jan 2020

Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan

Cal Poly Humboldt theses and projects

The intraspecific genetic variation and diversity within the Humboldt’s flying squirrel (Glaucomys oregonensis) has not yet been characterized despite its elevation to full species in 2017. The San Bernardino flying squirrel (G. o. californicus) is thought to be the southernmost population of G. oregonensis and is restricted to the San Bernardino and San Jacinto Mountains in California, but recent surveys indicate they have been extirpated from the latter locality. In order to provide baseline genetic data across the geographic range of G. oregonensis, I had the following objectives: 1) investigate the intraspecific molecular variation in …


Is Context Dependency Imperative To Understanding The Impacts Of Invasive Plants?, Brendan B. Haile Jan 2020

Is Context Dependency Imperative To Understanding The Impacts Of Invasive Plants?, Brendan B. Haile

Masters Theses

Introduced exotic species have a tendency to become invasive and impact local biological communities. Invasions often impact community attributes such as cover and species richness, but these factors may also regulate patterns of invasion. In such cases, impacts may be dependent on the invasion context. We used data from the Buell-Small Succession Study, a long-term permanent plot study in the piedmont region of New Jersey, to document context dependency in invasion. To do this, we analyzed the factors that affected the colonization and growth of four invasive species, Alliaria petiolata, Lonicera japonica, Microstegium vimineum and Rosa multiflora, as well …


Intraspecific Aggression Towards Common Bottlenose Dolphin Calves, Northern Gulf Of Mexico, Errol Ronje, Sarah Piwetz, Heidi Whitehead, Keith D. Mullin Jan 2020

Intraspecific Aggression Towards Common Bottlenose Dolphin Calves, Northern Gulf Of Mexico, Errol Ronje, Sarah Piwetz, Heidi Whitehead, Keith D. Mullin

Gulf and Caribbean Research

Infanticide has been widely documented throughout the animal kingdom, and has generally been viewed as an evolved, or adaptive behavior for the perpetrators. Infanticide motivated by increased sexual access to females with calves, or the elimination of potential genetic competition in the form of calf-directed aggression or infanticide, has been proposed for delphinids including killer whales, Indo-Pacific humpback dolphins, Guiana dolphins, and bottlenose dolphins. However, reports of intraspecific aggression towards bottlenose dolphin calves are relatively infrequent, and accounts of confirmed infanticide are rarer still. Reporting instances of intraspecific calf-directed aggression aids researchers to better understand the socio-behavioral context of these …


Landscape Ecology And Population Genomics Of Two Sympatric Pitviper Species Across A Fragmented Appalachian Landscape, Thomas Maigret Jan 2020

Landscape Ecology And Population Genomics Of Two Sympatric Pitviper Species Across A Fragmented Appalachian Landscape, Thomas Maigret

Theses and Dissertations--Biology

Understanding the link between landscape patterns and ecological and evolutionary processes is an important prerequisite for informed wildlife conservation and management, especially in rapidly changing landscapes. Until recently, the inaccessibility of spatial and genomic data sets of sufficient resolution limited our ability to incorporate the impacts of landscape patterns into predictions of ecological and environmental outcomes. In this dissertation, I utilized several high-resolution spatial and genomic data sets to address ecological questions in a rapidly fragmenting landscape in southeastern Kentucky. Overall, my results indicate that large-scale surface coal mining is causing widespread homogenization of landforms, resulting in a uniquely permanent …


Current Dog Breeding Practices Impacts On Health And Preservation Of Purebred Dogs, Bridget E. Baker Jan 2020

Current Dog Breeding Practices Impacts On Health And Preservation Of Purebred Dogs, Bridget E. Baker

Honors Theses and Capstones

No abstract provided.


Black Bear, Jimmy D. Taylor, James P. Phillips Jan 2020

Black Bear, Jimmy D. Taylor, James P. Phillips

Wildlife Damage Management Technical Series

The American black bear (Ursus americanus, Figure 1) is a challenging species for wildlife agencies to manage due to its size, intelligence, extensive range, food habits, and adaptability, as well as societal views. In North America alone, agencies receive more than 40,000 complaints about black bear annually. Black bears are known as ‘food-driven’ animals, meaning most conflicts result from a bear’s drive to meet its nutritional needs. Not surprisingly, an overwhelming proportion of conflicts are related to their use of anthropogenic (human) food sources, such as garbage, bird food, and crops. Understanding what drives human-bear conflict is the first part …


Vertebrate Natural History Notes From Arkansas, 2020, C. Renn Tumlison, Matt Connior, Blake Sasse, Henry Robison, Stan Trauth, S Higdon, L Baer, Z. Baer, R. Stinson, D. Carson, T. Inebnit, L. Lewis, Roger Perry, Ron Redman Jan 2020

Vertebrate Natural History Notes From Arkansas, 2020, C. Renn Tumlison, Matt Connior, Blake Sasse, Henry Robison, Stan Trauth, S Higdon, L Baer, Z. Baer, R. Stinson, D. Carson, T. Inebnit, L. Lewis, Roger Perry, Ron Redman

Journal of the Arkansas Academy of Science

Smaller details of natural history often go undocumented to science if those details are not parts of larger studies, but small details can provide insights that lead to interesting questions about ecological relationships or environmental change. We have compiled recent important observations of distribution and reproduction of fishes and mammals. Included are new distributional records of mammals, and observations of reproduction in several mammals for which few data exist in Arkansas. A rare record of the Long-tailed weasel, a special of special concern in Arkansas, is documented from Newton Co. We also provide evidence that Seminole bats likely reproduce in …


The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler Jan 2020

The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler

Cal Poly Humboldt theses and projects

Early successional wetland habitat is being lost in temperate regions worldwide as a result of changes in disturbance regimes that allow for the establishment and dominance of woody species. In particular, this phenomenon is pronounced in fens, which harbor high numbers of rare herbaceous species that require early successional habitat. I investigated the relationship between woody vegetation encroachment and herbaceous species diversity within a Northern California coastal fen that has been undergoing encroachment by woody vegetation for ca. 80 years by recording species richness and cover data from 338 permanent plots throughout the fen. I also investigated the effect of …


Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong Jan 2020

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …


Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel Jan 2020

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …