This dataset contains the taxonomic classifications of environmental DNA (eDNA) sequences obtained from Fall Creek, Oregon, via microfluidic multiplex PCR (Fluidigm Access Array) and high-throughput sequencing. It is accompanied by electrofishing counts taken at the same time as the eDNA samples. Metadata and R scripts are provided to analyze the...
The social sciences have the capacity to contribute to natural resource management through investigations of human dynamics associated with the environment. Sense of place (SOP), the formed relationships between an individual and the environment, has been considered a fundamental aspect of human well-being and can contribute to more holistic understanding...
Vibrio coralliilyticus (Vcor) is a bacterial pathogen that is well adapted to shellfish hatcheries and is very pathogenic to the larvae of the Pacific oyster Crassostrea gigas. Vcor has been associated with several large scale larval mortality events in the Pacific Northwest that interrupt the supply of seed oysters available...
Models of a species’ distribution and models of a species’ spatially explicit density are valuable tools for conservation. They allow researchers to estimate changes in distributions, densities, and populations, based on changing environmental conditions. To trust such estimates, however, the quality of models is exceedingly important. Model performance can be...
Movement in an important component of an animal’s life cycle when it relies on both aquatic and terrestrial habitats. When multiple species overlap in the use of these habitats, they rely on other methods to reduce competition for shared resources. This dataset measured the jumping performance and movement behavior of...
This study used a factorial mesocosm design to quantify American bullfrog (Lithobates castebeianus) eDNA to assess the relationship between body size, density, and eDNA shedding rates.
The influence of the flood pulse on fish populations has been posited, but infrequently tested or quantified. Here, we tested the effect of habitat on population size, using Prochilodus nigricans as a case study species. Floodplain habitat was based on the littoral zone area occupied by P. nigricans to feed....
Predator outbreaks are predicted to increasingly decimate economically and ecologically important prey populations because global climate change and food-web modifications frequently facilitate predators and stress prey. Natural systems are organized hierarchically, with processes operating at multiple scales giving rise to patterns of biodiversity, so predicting and managing outbreaks requires a...
The mission of federal fish hatcheries has evolved over decades under budgetary changes and new conservation regulations and policies. I evaluated the US Fish and Wildlife Service Abernathy Fisheries Technology Center, which has experienced this evolution from a production fish hatchery with research programs to a non-production, cutting edge, basic...
1. Rearing environments can shape offspring phenotype across taxa, yet little is known about how brood size influences hypothalamic-pituitary axis functioning, whether its expression trades off with growth, and the degree to which these -relationships vary between species.
2. We evaluated how brood size influenced nestling physiological (glucocorticoids) and somatic...
During traditional boat-based surveys of marine megafauna, behavioral observations are typically limited to records of animal surfacings obtained from a horizontal perspective. Achieving an aerial perspective has been restricted to brief helicopter or airplane based observations that are costly, noisy, and risky. The emergence of commercial small unmanned aerial systems...
This study investigates the use of a mobile application, Whale mAPP, as a citizen science tool for collecting marine mammal sighting data. In just over three months, 1261 marine mammal sightings were observed and recorded by 39 citizen scientists in Southeast Alaska. The resulting data, along with a preliminary and...
Ecotourism is a movement that seeks to sustain local communities by uniting conservation, travel, and education. To minimize effects on animal behavior, ecotourism operations must be carefully managed. Local management efforts that can be tailored to the specific area and animals may be more successful than broad‐scale efforts that may...
Declines in wild salmonid (Oncorhynchus spp.) populations in the Columbia River basin have resulted in managers identifying that avian predation on juvenile salmonids is an important limiting factor for salmonid recovery. Caspian Terns (Hydroprogne caspia), particularly those nesting in the Columbia River estuary, were identified as key avian predators that...
Small-scale fisheries (SSF) around the world face many challenges. They are a highly dynamic, important sector for coastal communities in developing nations, playing a critical role in poverty alleviation and food security. SSFs generally have few resources to ensure their long-term sustainability. They are often fished and managed locally and...
Many marine mammal predators, particularly pinnipeds, have increased in abundance in recent decades, generating new challenges for balancing human uses with recovery goals via ecosystem-based management. We used a spatio-temporal bioenergetics model of the Northeast Pacific Ocean to quantify how predation by three species of pinnipeds and killer whales (Orcinus...
The management of small-scale fisheries (SSF) around the world is facing increasing demands for reformation given ecological, social, and economic vulnerabilities. The governance of SSF is particularly important to foster the sustainability of these systems given that it combines regulatory instruments, interactive participation of diverse stakeholders, and the guiding values...
Pacific harbor seals (Phoca vitulina richardii) are one of Oregon’s most common coastal predators, numbering between 10,000 and 12,000 individuals (Brown et al. 2005b). They consume more than 149 species or types of marine prey within the Pacific Northwest, which include a large variety of commercially important fisheries species. Despite...
2018 Library Undergraduate Research Awards nomination materials, reflective learning essay, and research paper.
In this study, pocket gopher and gray-tailed vole holes and hills were counted within four distinct habitats using quadrats and a gridding method over a period of five field days. The study was conducted to determine which...
Migration and spawning phenology of Pacific Salmon is linked to the hydroregime, and thought to be triggered by increases in river discharge and decreases in water temperature. However, little data exists that describes direct fine-scale linkages between the hydroregime and spawning in Coho Salmon. This study evaluated the spatial and...
Coastal wetland plants are adapted to varying degrees of inundation. However, functional relationships between inundation and productivity are poorly characterized for most species. Determining species-specific tolerances to inundation is necessary to evaluate sea-level rise (SLR) effects on future marsh plant community composition, quantify organic matter inputs to marsh accretion, and...
Year-round habitat use of marine predators provides knowledge of important marine areas throughout different life stages. Large-scale, environmental variability, both in space and time, causes changes in the behavior and distribution of marine predators that are important to quantify for conservation. In the Northern California Current System (NCCS), common murres...
Declines in populations of anadromous salmonids (Oncorhynchus spp.) in the Columbia River drainage basin have resulted in extensive programs to annually release large numbers of hatchery-raised juvenile salmonids in an effort to support salmonid restoration. The Pacific Flyway population of Caspian terns (Hydroprogne caspia) has grown from around 3,500 nesting...
Fishers (Pekania pennanti) are medium sized mustelids endemic to North America. Two fisher populations persist in Oregon: an indigenous population in southwestern Oregon, and a reintroduced population in the southern Cascade Mountains. Despite candidacy for listing under the Endangered Species Act, current information on fisher populations in Oregon is scarce....
For over 100 years, National Parks have existed to preserve America’s natural and cultural heritage for current and future generations. As environmental pressures on wildlife and habitats have increased in recent decades, National Park lands have become important protected areas for many threatened and endangered species. Conservation and management of...
Species conservation depends on robust population assessment. Data on population abundance, distribution, and connectivity are critical for effective management, especially as baseline information for newly documented populations. I describe a pygmy blue whale (Balaenoptera musculus brevicauda) population in New Zealand waters with year-round presence that overlaps with industrial activities. This...
Background. Ampelisca eschrichtii Krøyer, 1842 of the Sakhalin Shelf of the Okhotsk Sea, Far Eastern Russia, comprise the highest known biomass concentration of any amphipod population in the world and are a critically important prey source for western gray whales. Growth and reproduction in this population has not been apparent...
Up to 99.9% of native North American grasslands have been degraded since European settlement, primarily due to agricultural conversion. Today, grasslands are a top priority for restoration as they provide essential habitat for many rare and endangered species; however, the majority of studies in grasslands have focused on vegetation or...
Fisheries-related mortality has been influential in driving global declines in seabird populations. Understanding the overlap between seabird distribution and fisheries is one important element in assessing bycatch risk, and may be achieved by tracking the movements of individual birds and fishing vessels. Here, we assess the spatiotemporal overlap between the...
Recent studies have demonstrated that some hormones are present in baleen powder from bowhead (Balaena mysticetus) and North Atlantic right (Eubalaena glacialis) whales. To test the potential generalizability of this technique for studies of stress and reproduction in large whales, we sought to determine whether all major classes of steroid...
The dynamic nature of most environments forces many animals to move to meet their fundamental needs. This is especially true in aquatic environments where shifts in spatial ecology (which are a result of movements) are among the first adaptive responses of animals to changes in ecosystems. Changes in the movement...
Research on cetacean foraging ecology is central to our understanding of their spatial and behavioral ecology. Yet, functional mechanisms by which cetaceans detect prey across different scales remain unclear. Here, I postulate that cetaceans utilize a scale-dependent, multimodal sensory system to assess and increase prey encounters. I review the literature...
Biodiversity loss in highly diverse systems such as coral reefs has been linked to significant declines in the ecosystem functions and services provided by marine species. Ecological functioning of coral reefs and the resistance of coral reef fish communities to disturbance depend on the functional traits of species that promotes...
Using a combination of population‐ and individual‐based analytical approaches, we provide a comprehensive examination of genetic connectivity of Dungeness crab (Cancer magister) along ~1,200 km of the California Current System (CCS). We sampled individuals at 33 sites in 2012 to establish a baseline of genetic diversity and hierarchal population genetic...
Limited approaches exist for studying population connectivity in widely dispersing marine benthic invertebrates. Genetic techniques can provide important insights toward identifying recruitment trajectories. Here, 10 microsatellite loci were used to examine connectivity among Oregon Dungeness crabs (Cancer magister, Dana, 1852) in the California Current System (CCS) (n = 801) as...
Bird scaring lines (BSLs) protect longline fishing gear from seabird attacks, save bait, reduce incidental seabird mortality and are the most commonly prescribed seabird bycatch mitigation measure worldwide. We collaborated with fishermen to assess the efficacy of applying BSL regulations from the demersal longline sablefish fishery in Alaska to a...
Two species of burrowing shrimp occur in high densities in US West Coast estuaries, the ghost shrimp, Neotrypaea californiensis, and the blue mud shrimp, Upogebia pugettensis. Both species of shrimp are considered ecosystem engineers as they bioturbate and irrigate extensive galleries within the sediment. While their burrows comprise a dominant...
Understanding connectivity of marine organisms is necessary for determining the appropriate scale of conservation and management strategies. For species that inhabit both the coastal ocean and partially enclosed water bodies (i.e., estuaries or fjords), this information is even more critical since estuaries and fjords are often characterized by hydrological complexities...
Juvenile salmonids display highly variable spatial and temporal patterns of early dispersal that are influenced by density-dependent and density-independent factors.
Although juvenile coho salmon (Oncorhynchus kisutch) movement patterns in streams and their relationship with body mass and growth have been examined in previous studies, most observations were limited to one...
Since the decimation of the southern right
whale Eubalaena australis population in New Zealand by
whaling, research on its recovery has focused on the wintering
ground at the Auckland Islands, neglecting potentially
important wintering habitat at Campbell Island. For
the first time in 20 years we conducted an expedition to...
Periodic weighing of seabird chicks is labour-intensive and repeated handling can cause high levels of disturbance to chicks. Although automatic weighing systems using a fibreglass nest have been designed for albatross species with a pedestal nest made of mud, this approach is inappropriate for great albatross species (genus Diomedea) whose...
Streams that dry during part of the year are common throughout the world, yet studies of the macroinvertebrate assemblages in these types of streams are rare compared to those in permanent streams; and studies that assess the effects of agriculture on temporary stream invertebrates are even rarer. We studied macroinvertebrate...
Characiform fishes form one of the most diverse freshwater fish clades in the world. Comprising more than 2000 species and distributed primarily in South America and Africa, characiforms vary dramatically in their ecomorphology. However, the evolutionary processes responsible for the immense ecomorphological diversity remains unknown. Recently, a study postulated that...
Humpback whales (Megaptera novaeangliae) are a widely distributed baleen whale species, well known for their diverse acoustic behavior. On high-latitude foraging grounds, humpback whales produce a suite of non-song vocalizations (“calls”) in concert with foraging and social behavior. In this dissertation I investigated the role of calls in the acoustic...
Background. Ampelisca eschrichtii Krøyer, 1842 of the Sakhalin Shelf of the Okhotsk Sea, Far Eastern Russia, comprise the highest known biomass concentration of any amphipod population in the world and are a critically important prey source for western gray whales. Growth and reproduction in this population has not been apparent...
Identification and classification of behavior states in animal movement data can be complex, temporally biased, time-intensive, scale-dependent, and unstandardized across studies and taxa. Large movement datasets are increasingly common and there is a need for efficient methods of data exploration that adjust to the individual variability of each track. We...
Cytochrome B sequence data (FASTA format) from the paper “Seasonal distribution and environmental associations among late larval and juvenile rockfish (Sebastes spp.) off Oregon and Washington: new insights based on genetics”. The data was generated from a sample of 2534 unknown, field collected late-larval and juvenile rockfishes from the Pacific...
Informed conservation of small mammals, ecosystems, and predators requires a detailed understanding of how small mammals species and communities vary in both space and time, as well as the relative cyclicity and synchrony of this variation. This variation can be especially informative to land managers interested in manipulating the abundance...
The Western Pacific Ocean barred knifejaw Oplegnathus fasciatus was found from 2013 to 2015 along the Pacific Coast of North America from Washington to California. The knifejaw was found in derelict vessels that had arrived on the Pacific Coast and that had been lost during the March 2011 Great Japan...
Background: Despite recent work to characterize gene expression changes associated with larval development in oysters, the mechanism by which the larval shell is first formed is still largely unknown. In Crassostrea gigas, this shell forms within the first 24 h post fertilization, and it has been demonstrated that changes in...
OBJECTIVE To document the environmental stewardship practices (decisions and actions regarding use and disposal) of pet and human pharmaceuticals and personal care products (PPCPs) among pet-owning veterinary-care professionals (practicing veterinarians, veterinary students, and veterinary technicians and trainees) and environmental educators. DESIGN Internet-based cross-sectional survey. SAMPLE 191 pet owners (103 veterinary-care...
Cross-seasonal effects, where conditions in one season can have consequences in a following season, can have population-level implications for migratory species. To assess the presence of cross-seasonal effects on a migratory dabbling duck population, we examined the relative importance of habitat conditions in multiple seasons on the subsequent productivity of...
In this study, we used a combination of conventional statistical analyses and mechanistic bioenergetics models to understand the potential effects of environmental variability on growth of stream-living fishes in four headwater streams subject to upstream forest harvest. We focused on two common fish consumers in headwater streams in the Pacific...
Collaborative decision-making is often promoted as a means to achieve socially acceptable and enduring solutions to natural resource management issues, and one that holds promise for resolving “wicked” problems. However, success rates for implementation of collaborative recommendations are unknown. This paper explores challenges to collaborative salmon fishery management in Prince...
We sought to characterize the distribution of juvenile walleye pollock Theragra chalcogramma in an area of intense predator-prey interactions and to describe habitat features that lead to their observed distributions. The distribution of juvenile walleye pollock around the Pribilof Islands in the southeastern Bering Sea in 2008 and 2009 was...
California bighorn sheep (Ovis canadensis californiana) were studied on Hart Mountain, Oregon, during the summer and fall of 1976, and the spring of 1977. The population consisted of a minimum of 196 sheep in June, 1977. The high number of lambs observed and high lamb:ewe ratios throughout both years of...
Commercial whaling during the 20th century drastically reduced many populations of great whales in the Southern Hemisphere. The Antarctic blue whale, for example, is estimated to have been reduced to less than 0.1% of its original abundance based on catch records and population dynamic models. Despite this population bottleneck, several...
From July 1985 to April 1987 the pelagic zooplankton community of Crater Lake, Oregon was studied to determine taxonomic structure, absolute and relative densities, and spatial and temporal distributional patterns. Samples were collected using vertically-towed zooplankton nets. The community structure consisted of two cladoceran and nine rotifer species, which were...
Monitoring marine ambient sound using standardized methods supports assessments of ocean sound levels across widespread ecosystems. This thesis quantifies differences among coastal and deep-water marine soundscapes in the Atlantic and Pacific oceans. The sources of sound in a soundscape are compartmentalized into three components and compared over time and among...
Human alterations of landscapes take many forms, one of which is anthropogenic pollution. Mercury (Hg) is a complex contaminant because its uptake into the food web is not driven entirely by loading to the system; methylation is necessary to make Hg bioavailable and toxic to fish and wildlife. Because methylation...
Humpback whale populations in Antarctica are recovering after intensecommercial whaling in the 20th century. Along the Western Antarctic Peninsula (WAP)this recovery is occurring in an environment that is experiencing the fastest warming ofany region on the planet. To begin to understand the dynamics of this recovery undersuch dramatic climate change,...
One of the biggest hurdles for a juvenile salmonid (Oncorhynchus mykiss) is migrating downstream from freshwater spawning grounds to the ocean. Juveniles from wild broodstock were reared from the South Santiam River for more than 1 year at the Oregon Hatchery Research Center (OHRC) in Alsea, OR. The fish were...
The desire to understand the spatial and temporal drivers of animal behavior and distribution relative to scale is central to movement ecology. Optimal foraging theory states that a predator should continue exploiting a patch until it is no longer profitable to do so. As human developments increasingly encroach on the...
Ecological resources available to freshwater fish shift spatially, temporally and across life stages. To better understand how spatial-temporal availability of resources influence fish, I examined the phenologies of hatching and emergence of Coho Salmon (Oncorhynchus kisutch) in streams with contrasting and strongly defined seasonal thermal variability. The study streams included...
Traditional analysis in population genetics evaluates differences among groups of individuals and, in some cases, considers the effects of distance or potential barriers to gene flow. However, many forces may shape genetic variation of organisms in riverine systems. Similarly complex research linking habitat heterogeneity and configuration to genetic structure has...
Historically fire has been the primary disturbance factor in the sagebrush-steppe. The settlement of the West by Euro-Americans, grazing by domestic livestock, and the concomitant spread of invasive species have altered the historical fire regime. Understanding the long-term vegetation structure and fuel succession of the various sagebrush-dominated communities of this...
Tropical peatlands play an important role in global climate system by storing an immense of carbon that had been accumulated over thousands of years. Peatlands provide another important ecosystem service by regulating the hydrology. It is believed that peatlands act like a giant sponge by absorbing substantial amounts of water...
Forecasts of the impacts of climate change have traditionally focused on individual species and their phenotypes, phenology, or distribution. However, shifts in species distributions and the resulting reorganization of community composition represent an important violation to the assumption of species acting in isolation. Whereas species may respond individualistically to climate...
This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5...
The Mahakam Delta which was once among the largest mangrove forests in Indonesia, has been subjected to dramatic changes in structure and function due to massive shifts from mangrove forest to shrimp ponds and oil and gas development. To understand the impacts of mangrove loss to the greenhouse gas (GHG)...
ABSTRACT: In 2006 Alaska’s first artificial reef (AR) was deployed as mitigation for habitat lost due to coastal development. Surveys conducted the following year suggested AR assemblages resembled those of adjacent natural reefs (NR). However, there is little known about the ecological succession of AR’s long-term in high latitude locations....
Over half of the U.S. coastline is found in Alaska, and the majority of the state’s economic activity occurs along the coast. Increased coastal development poses a potential threat to nearshore habitats in Alaska. The installation of artificial reef (AR) systems can mitigate habitat loss; however, few AR systems have...
Traditional visual survey methods for marine mammals can only detect a fraction of the animals present. Even if the animal can be observed from the surface, visual limitations such as time of day and weather conditions can impede this ability. Recent advances in passive acoustic monitoring technologies have led to...
Despite being a highly charismatic and frequently exhibited organism,
Giant Pacific Octopus (Enteroctopus dofleini) population dynamics
are poorly understood. Basic monitoring data for this species is
limited to bycatch and stomach contents of other fisheries species. An
essential step to a better estimation of population size and
productivity is to...
The direct and indirect effects of ocean acidification (OA) are a growing concern, particularly in areas already experiencing elevated levels of oceanic CO₂. Studies with marine fishes suggest that elevated CO₂ levels may affect behavior by interfering with an important brain neurotransmitter. Studies examining the effects of OA fish behavior...
Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated...
In salmon-rich, northern coastal environments brown bears can occur at high densities and exert wide-ranging effects on ecosystem processes. Bear consumption of seasonally available fruit may provide important seed dispersal services to plants, and by extension, influence the ecology of seed consumers such as small mammals. In this study, we...
Listed as endangered in 1988, the Lost River sucker (Deltistes luxatus) and Shortnose sucker (Chasmistes brevirostris) were once abundant and widely distributed in the Klamath Basin in Southern Oregon and Northern California. Populations of both species have been declining since the late 1960’s. Factors thought responsible for declines include naturally...
For many species of oceanic dolphins, photo-identification and genetic data indicate that these island-associated populations are demographically isolated from pelagic populations and that island-associated populations exhibit very different patterns of movement and habitat use. Melon-headed whales (Peponocephala electra) are generally considered a pelagic dolphin, but have been documented around oceanic...
Tidal marshes are dynamic ecosystems that are threatened by climate change and sea-level rise. To characterize baseline condition and historic climate sensitivities, and improve projections into the future, new methods are required that integrate data from the field and remote sensing platforms. Marsh elevation response models can be calibrated with...
Experiments were conducted to determine survival, growth, and accumulation of HEOD (major component of dieldrin) in the tissues of steelhead trout (Salmo gairdneri) embryos, alevins, and fry exposed to dieldrin concentrations ranging from 0.012 to 52 ppb. The fish were held in specially designed exposure chambers provided with continuously renewed...
The early marine phase following freshwater emigration has been identified as a critical period in salmonid (Oncorhynchus spp.) life history, characterized by high but variable mortality. Consistent with the “growth-mortality” and “bigger-is-better” hypotheses, at least some of the mortality during the critical period appears to be size-dependent – with smaller...
The marine environment is under increasing pressure from human activities worldwide, particularly in coastal waters, creating a need to better understand fine-scale distributions of highly mobile species that occur in the area, as they are frequently most threatened. Harbor porpoise (Phocoena phocoena) occur frequently in Oregon’s nearshore habitat, but due...
Plants often encase seeds in a nutritional reward to incentivize seed dispersal by birds and mammals, but these seeds may also be removed and destroyed by seed predators. Although birds are typically thought to be the primary seed dispersers of berries in temperate systems, in southeast Alaska and other salmon-bearing...
The effects of Marine protected areas (MPAs) on adult fish populations depend on the degree of protection provided, which is partly a function of MPA size and the spatial extent of fish movements. The Redfish Rocks Marine Reserve (RRMR) and MPA, located on the south coast of Oregon near Port...
Climate-induced range overlap can result in novel interactions between similar species and potentially lead to competitive exclusion. The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth and is experiencing a poleward climate migration. This transition from a polar to sub-polar environment has resulted in a...
This report summarizes a study which sought to provide toxicity data for pulp mills near Coos Bay through a series of toxicity bioassays. The study also surveyed benthic and beach fauna to identify macro-organisms so individual assessments of water quality requirements could be made.
Juvenile Chinook Salmon (Oncorhynchus tshawytscha) have a finite amount of energy that they can use to move from their riverine habitat to their oceanic habitat. Fish in the Willamette River Basin are prevented from moving to the ocean easily by dams which create reservoirs, where they reside for up to...
Understanding connectivity among exploited populations is critical to their sustainable management and long-term viability. In the marine environment, estimates of connectivity often rely on the use of genetic markers, as dispersal primarily occurs during a planktonic larval phase which is difficult to track using direct methods. In this thesis, we...
Accumulating human impacts on freshwater ecosystems have created a biodiversity crisis for freshwater fishes while conservation efficacy remains hampered by the Linnaean shortfall, the ignorance of many species that have yet to be discovered and described. The past discovery of most freshwater fish species was simply a matter of collecting...
Group foraging is observed in many species as a means to increase the ability of members of the group to find and exploit patchy prey. Group foraging can be exhibited in a number of different contexts based on the relationships between the participants, including by-product mutualism. One variant of by-product...
Thiamine (vitamin B₁) is required by all living organisms for carbohydrate metabolism and synthesis of amino acids. Thiamine deficiency is responsible for several related classes of early life stage mortality disorders in salmonines, including Thiamine Deficiency Complex (TDC) in the Laurentian Great Lakes, Cayuga Syndrome in the Finger Lakes, and...
Efficient foraging strategies result in a predator spatially overlapping with its prey, foraging in the most profitable patches, and minimizing the time transiting between patches. Previous studies investigating baleen whale foraging strategies have generally focused on investigating spatial overlap with prey patches, patch profitability or movement within feeding grounds. The...
More than 1500 species of plants and animals in the United States are listed as threatened or endangered under the Endangered Species Act (ESA). The U.S. Departments of Interior and Commerce are required, under Section 4(f)(1) of the ESA, to develop recovery plans for ESA-listed species under the respective agency...
The Cackling goose (Branta hutchinsii minima) population has increased from a low of 20,000 in 1984 to the current population of 220,000-300,000 (Stehn 2012, Sanders 2013). As the Cackling goose population began to recover in the late 1990s, the majority of the population relocated from wintering in California to the...
We evaluated the impact of predation on juvenile steelhead Oncorhynchus mykiss and yearling and subyearling Chinook Salmon O. tshawytscha by piscivorous waterbirds from 11 different breeding colonies in the Columbia River basin during 2012 and 2014. Fish were tagged with both acoustic tags and PIT tags and were tracked via...
The interplay of natural selection and genetic drift, influenced by geographic isolation, mating systems and population size, determines patterns of genetic diversity within species. The sperm whale provides an interesting example of a long-lived species with few geographic barriers to dispersal. Worldwide mtDNA diversity is relatively low, but highly structured...