Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| explicit not implicit preferences predict conservation intentions for endangered species and biomes. | conservation of biodiversity is determined in part by human preferences. preferences relevant to conservation have been examined largely via explicit measures (e.g., a self-reported degree of liking), with implicit measures (e.g., preconscious, automatic evaluations) receiving relatively less attention. this is the case despite psychological evidence from other contexts that implicit preferences are more informative of behavior. thus, the type of measure that predicts conservation intentions for ... | 2017 | 28135298 |
| isolation and characterization of a novel marine brucella from a southern sea otter (enhydra lutris nereis), california, usa. | we characterize brucella infection in a wild southern sea otter ( enhydra lutris nereis) with osteolytic lesions similar to those reported in other marine mammals and humans. this otter stranded twice along the central california coast, us over a 1-yr period and was handled extensively at two wildlife rehabilitation facilities, undergoing multiple surgeries and months of postsurgical care. ultimately the otter was euthanized due to severe, progressive neurologic disease. necropsy and postmortem ... | 2017 | 28151078 |
| novel urease-negative helicobacter sp. 'h. enhydrae sp. nov.' isolated from inflamed gastric tissue of southern sea otters. | a total of 31 sea otters enhydra lutris nereis found dead or moribund (and then euthanized) were necropsied in california, usa. stomach biopsies were collected and transected with equal portions frozen or placed in formalin and analyzed histologically and screened for helicobacter spp. in gastric tissue. helicobacter spp. were isolated from 9 sea otters (29%); 58% (18 of 31) animals were positive for helicobacter by pcr. the helicobacter sp. was catalase- and oxidase-positive and urease-negative ... | 2017 | 28177288 |
| endemic infection of stranded southern sea otters (enhydra lutris nereis) with novel parvovirus, polyomavirus, and adenovirus. | over the past century, the southern sea otter (sso; enhydra lutris nereis) population has been slowly recovering from near extinction due to overharvest. the sso is a threatened species under federal law and a fully protected species under california law. through a multiagency collaborative program, stranded animals are rehabilitated and released, while deceased animals are necropsied and tissues are cryopreserved to facilitate scientific study. here, we processed archival tissues to enrich part ... | 2017 | 28192039 |
| inter-decadal patterns of population and dietary change in sea otters at amchitka island, alaska. | after having been hunted to near-extinction in the pacific maritime fur trade, the sea otter population at amchitka island, alaska increased from very low numbers in the early 1900s to near equilibrium density by the 1940s. the population persisted at or near equilibrium through the 1980s, but declined sharply in the 1990s in apparent response to increased killer whale predation. sea otter diet and foraging behavior were studied at amchitka from august 1992 to march 1994 and the data compared wi ... | 2000 | 28308190 |
| foraging strategies and prey switching in the california sea otter. | southern sea otters (enhydra lutris nereis), in recovering from near extinction, are gradually extending their range to include areas from which they have been absent for more than one hundred years. this study took advantage of the otters' relatively sudden arrival in the area near santa cruz, california, to monitor their prey selection in the first two years of residence there. foraging observations revealed that sea urchins (strongly-locentrotus franciscanus) were heavily preyed upon initiall ... | 1982 | 28311106 |
| mitogenomes and relatedness do not predict frequency of tool-use by sea otters. | many ecological aspects of tool-use in sea otters are similar to those in indo-pacific bottlenose dolphins. within an area, most tool-using dolphins share a single mitochondrial haplotype and are more related to each other than to the population as a whole. we asked whether sea otters in california showed similar genetic patterns by sequencing mitogenomes of 43 otters and genotyping 154 otters at 38 microsatellite loci. there were six variable sites in the mitogenome that yielded three haplotype ... | 2017 | 28330975 |
| serologic detection of subtype-specific antibodies to influenza a viruses in southern sea otters (enhydra lutris nereis). | there are approximately 3,000 southern sea otters (enhydra lutris nereis) in the nearshore environment along the california coast, and the species is classified as threatened under the endangered species act. we tested sera from 661 necropsied southern sea otters sampled from 1997 to 2015 to determine overall exposure to influenza a viruses (iavs) and to identify subtype-specific antibody responses. using an enzyme-linked immunosorbent assay (elisa), antibodies to iav nucleoproteins were detecte ... | 2017 | 28513329 |
| discovery of the fossil otter enhydritherium terraenovae (carnivora, mammalia) in mexico reconciles a palaeozoogeographic mystery. | the north american fossil otter enhydritherium terraenovae is thought to be partially convergent in ecological niche with the living sea otter enhydra lutris, both having low-crowned crushing teeth and a close association with marine environments. fossil records of enhydritherium are found in mostly marginal marine deposits in california and florida; despite presence of very rich records of fossil terrestrial mammals in contemporaneous localities inland, no enhydritherium fossils are hitherto kn ... | 2017 | 28615353 |
| first report of an adult tapeworm (cestoda: diphyllobothriidea) in a southern sea otter (enhydra lutris nereis). | we present a novel case of an intestinal cestode infection in a southern sea otter (enhydra lutris nereis). the cestode species diplogonoporus tetrapterus was confirmed genetically. stable isotope analysis of whiskers collected from the sea otter did not confirm the consumption of fish as the route of exposure. | 2017 | 28640666 |
| oil spills and marine mammals in british columbia, canada: development and application of a risk-based conceptual framework. | marine mammals are inherently vulnerable to oil spills. we developed a conceptual framework to evaluate the impacts of potential oil exposure on marine mammals and applied it to 21 species inhabiting coastal british columbia (bc), canada. oil spill vulnerability was determined by examining both the likelihood of species-specific (individual) oil exposure and the consequent likelihood of population-level effects. oil exposure pathways, ecology, and physiological characteristics were first used to ... | 2017 | 28695252 |
| brucella infection in asian sea otters (enhydra lutris lutris) on bering island, russia. | infection with brucella spp., long known as a cause of abortion, infertility, and reproductive loss in domestic livestock, has increasingly been documented in marine mammals over the past two decades. we report molecular evidence of brucella infection in asian sea otters (enhydra lutris lutris). brucella dna was detected in 3 of 78 (4%) rectal swab samples collected between 2004 and 2006 on bering island, russia. these 78 animals had previously been documented to have a brucella seroprevalence o ... | 2017 | 28715292 |
| other helicobacters, gastric and gut microbiota. | the current article is a review of the most important and relevant literature published in 2016 and early 2017 on non-helicobacter pylori helicobacter infections in humans and animals, as well as interactions between h. pylori and the microbiota of the stomach and other organs. some putative new helicobacter species were identified in sea otters, wild boars, dogs, and mice. many cases of helicobacter fennelliae and helicobacter cinaedi infection have been reported in humans, mostly in immunocomp ... | 2017 | 28891140 |
| optimal marine mammal welfare under human care: current efforts and future directions. | marine mammals include cetaceans, pinnipeds, sirenians, sea otters and polar bears, many of which are charismatic and popular species commonly kept under human care in zoos and aquaria. however, in comparison with their fully terrestrial counterparts their welfare has been less intensively studied, and their partial or full reliance on the aquatic environment leads to unique welfare challenges. in this paper we attempt to collate and review the research undertaken thus far on marine mammal welfa ... | 2018 | 28927965 |
| serendipity in a salt marsh: detecting frequent sea otter haul outs in a marsh ecosystem. | 2017 | 28960281 | |
| streptococcus phocae in marine mammals of northeastern pacific and arctic canada: a retrospective analysis of 85 postmortem investigations. | : streptococcus phocae is a pathogen of marine mammals, although its pathogenicity remains poorly understood. recovery of this bacterium from asymptomatic carriers suggests that it is an opportunistic pathogen. we investigated the role of s. phocae in naturally occurring disease and its significance as a pathogen based on postmortem investigations. between 2007 and 2012, 1,696 whole carcasses, tissue samples, or both were submitted from the northeastern pacific and arctic canada for diagnostic ... | 2018 | 28982020 |
| durophagous biting in sea otters (enhydra lutris) differs kinematically from raptorial biting of other marine mammals. | sea otters represent an interesting model for studies of mammalian feeding evolution. although they are marine mammals, sea otters returned to the sea relatively recently and feed at the surface. therefore, they represent a transitional stage of aquatic adaptation. currently no feeding performance studies of sea otters have been conducted. the main objective of this study was to characterize the feeding kinematic profile in sea otters. it was hypothesized that sea otters would exhibit a terrestr ... | 2017 | 29074703 |
| feeding capability in the extinct giant siamogale melilutra and comparative mandibular biomechanics of living lutrinae. | at 50 kg in estimated weight, the extinct siamogale melilutra is larger than all living otters, and ranks among the largest fossil otters. the biomechanical capability of s. melilutra jaws as related to their large size is unknown but crucial to reconstructing the species' potentially unique ecological niche. here we compare the mandibular biomechanics of s. melilutra using engineering-based performance measures against ten extant otter biomechanical models. despite a wide range of feeding prefe ... | 2017 | 29123190 |
| selective regimes and functional anatomy in the mustelid forelimb: diversification toward specializations for climbing, digging, and swimming. | anatomical traits associated with locomotion often exhibit specializations for ecological niche, suggesting that locomotor specializations may constitute selective regimes acting on limb skeletal traits. to test this, i sampled 42 species of mustelidae, encompassing climbing, digging, and swimming specialists, and determined whether trait variation reflects locomotor specialization by performing a principal components analysis on 14 forelimb traits. in addition to brownian motion models, three o ... | 2017 | 29152182 |
| ecosystem features determine seagrass community response to sea otter foraging. | comparing sea otter recovery in california (ca) and british columbia (bc) reveals key ecosystem properties that shape top-down effects in seagrass communities. we review potential ecosystem drivers of sea otter foraging in ca and bc seagrass beds, including the role of coastline complexity and environmental stress on sea otter effects. in bc, we find greater species richness across seagrass trophic assemblages. furthermore, cancer spp. crabs, an important link in the seagrass trophic cascade obs ... | 2018 | 29221592 |
| the genome of the northern sea otter (enhydra lutris kenyoni). | the northern sea otter inhabits coastal waters of the northern pacific ocean and is the largest member of the mustelidae family. dna sequencing methods that utilize microfluidic partitioned and non-partitioned library construction were used to establish the sea otter genome. the final assembly provided 2.426 gbp of highly contiguous assembled genomic sequences with a scaffold n50 length of over 38 mbp. we generated transcriptome data derived from a lymphoma to aid in the determination of functio ... | 2017 | 29232880 |
| mortality trends in northern sea otters ( enhydra lutris kenyoni) collected from the coasts of washington and oregon, usa (2002-15). | during 2002-15 we examined the causes of mortality in a population of northern sea otters ( enhydra lutris kenyoni). beachcast sea otters were collected primarily from the us coast of washington. although there are no permanent sea otter residents in oregon, several beachcast otters were collected from the oregon coast. infectious diseases were the primary cause of death (56%) for otters we examined. sarcocystosis was the leading infectious cause of death (54%) and was observed throughout the st ... | 2018 | 29261446 |
| size, growth, and density data for shallow-water sea urchins from mexico to the aleutian islands, alaska, 1956-2016. | size, growth, and density have been studied for north american pacific coast sea urchins strongylocentrotus purpuratus, s. droebachiensis, s. polyacanthus, mesocentrotus (strongylocentrotus) franciscanus, lytechinus pictus, centrostephanus coronatus, and arbacia stellata by various workers at diverse sites and for varying lengths of time from 1956 to present. numerous peer-reviewed publications have used some of these data but some data have appeared only in graduate theses or the gray literatur ... | 2018 | 29281144 |
| the dimensionality of individual niche variation. | the inherently multidimensional nature of the niche has not yet been integrated into the investigation of individual niche specialization within populations. we propose a framework for modeling the between- and within-individual components of the population niche as a set of variance-covariance matrices, which can be visualized with ellipses or ellipsoids. these niche components can be inferred using multiple response mixed models, and can incorporate diverse types of data, including diet compos ... | 2018 | 29282710 |
| monitoring dynamic spatio-temporal ecological processes optimally. | population dynamics vary in space and time. survey designs that ignore these dynamics may be inefficient and fail to capture essential spatio-temporal variability of a process. alternatively, dynamic survey designs explicitly incorporate knowledge of ecological processes, the associated uncertainty in those processes, and can be optimized with respect to monitoring objectives. we describe a cohesive framework for monitoring a spreading population that explicitly links animal movement models with ... | 2018 | 29369341 |
| bioerosion by pit-forming, temperate-reef sea urchins: history, rates and broader implications. | sea urchins are dominant members of rocky temperate reefs around the world. they often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these "pits." however, there are no experimental data demonstrating they bore pits. if they do, what are the rates and consequences of bioerosion to nearshore systems? we sampled purple sea urchins, strongylocentrotus purpuratus, from sites with four rock types, three sedimentary (two sandstones and one mudstone) and o ... | 2018 | 29466357 |
| are the ghosts of nature's past haunting ecology today? | humans have decimated populations of large-bodied consumers and their functions in most of the world's ecosystems. it is less clear how human activities have affected the diversity of habitats these consumers occupy. rebounding populations of some predators after conservation provides an opportunity to begin to investigate this question. recent research shows that following long-term protection, sea otters along the northeast pacific coast have expanded into estuarine marshes and seagrasses, and ... | 2018 | 29738721 |
| toxoplasma gondii infection in wild mustelids and cats across an urban-rural gradient. | the increase in human population and domestic pets, such as cats, are generating important consequences in terms of habitat loss and pathogen pollution of coastal ecosystems with potential to generate negative impacts in marine biodiversity. toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated with cat abundance and anthropogenic disturbance. the presence of t. gondii oocysts in the ocean has negatively affected the health status of the threatened south ... | 2018 | 29924844 |
| an update on toxoplasma gondii infections in northern sea otters (enhydra lutris kenyoni) from washington state, usa. | toxoplasmosis in marine mammals is epidemiologically and clinically important. toxoplasma gondii antibodies (by modified agglutination test, cut-off ≥1:25) were detected in serum of 65 of 70 (92.9%) northern sea otters (enhydra lutris kenyoni) from washington state, usa. brains and/or muscles of 44 sea otters were bioassayed in mice (inf-γ knock-out [ko], swiss webster outbred [sw]) and viable t. gondii was isolated from 22 of 44 (50%); t. gondii strains were lethal to ko mice but not sw mice. t ... | 2018 | 29941160 |
| collagen fingerprinting and the earliest marine mammal hunting in north america. | the submersion of late pleistocene shorelines and poor organic preservation at many early archaeological sites obscure the earliest effects of humans on coastal resources in the americas. we used collagen fingerprinting to identify bone fragments from middens at four california channel island sites that are among the oldest coastal sites in the americas (~12,500-8,500 cal bp). we document paleocoastal human predation of at least three marine mammal families/species, including northern elephant s ... | 2018 | 29968785 |
| sudden collapse of a mesopredator reveals its complementary role in mediating rocky reef regime shifts. | while changes in the abundance of keystone predators can have cascading effects resulting in regime shifts, the role of mesopredators in these processes remains underexplored. we conducted annual surveys of rocky reef communities that varied in the recovery of a keystone predator (sea otter, enhydra lutris) and the mass mortality of a mesopredator (sunflower sea star, pycnopodia helianthoides) due to an infectious wasting disease. by fitting a population model to empirical data, we show that sea ... | 2018 | 30051864 |
| defining the risk landscape in the context of pathogen pollution: toxoplasma gondii in sea otters along the pacific rim. | pathogens entering the marine environment as pollutants exhibit a spatial signature driven by their transport mechanisms. the sea otter (enhydra lutris), a marine animal which lives much of its life within sight of land, presents a unique opportunity to understand land-sea pathogen transmission. using a dataset on toxoplasma gondii prevalence across sea otter range from alaska to california, we found that the dominant drivers of infection risk vary depending upon the spatial scale of analysis. a ... | 2018 | 30109036 |
| active touch in sea otters: in-air and underwater texture discrimination thresholds and behavioral strategies for paws and vibrissae. | sea otters (enhydra lutris) are marine predators that forage on a wide array of cryptic, benthic invertebrates. observational studies and anatomical investigations of the sea otter somatosensory cortex suggest that touch is an important sense for detecting and capturing prey. sea otters have two well-developed tactile structures: front paws and facial vibrissae. in this study, we use a two-alternative forced choice paradigm to investigate tactile sensitivity of a sea otter subject's paws and vib ... | 2018 | 30224372 |
| complete genome sequence of a novel sea otterpox virus. | members of the poxviridae family are large, double-stranded dna viruses that replicate in the cytoplasm of their host cells. the subfamily chordopoxvirinae contains viruses that infect a wide range of vertebrates including marine mammals within the balaenidae, delphinidae, mustelidae, odobenidae, otariidae, phocidae, and phocoenidae families. recently, a novel poxvirus was found in a northern sea otter pup (enhydra lutris kenyoni) that stranded in alaska in 2009. the phylogenetic relationships o ... | 2018 | 30225673 |
| lactation and resource limitation affect stress responses, thyroid hormones, immune function, and antioxidant capacity of sea otters (enhydra lutris). | lactation is the most energetically demanding stage of reproduction in female mammals. increased energetic allocation toward current reproduction may result in fitness costs, although the mechanisms underlying these trade-offs are not well understood. trade-offs during lactation may include reduced energetic allocation to cellular maintenance, immune response, and survival and may be influenced by resource limitation. as the smallest marine mammal, sea otters (enhydra lutris) have the highest ma ... | 2018 | 30250713 |
| from the predictable to the unexpected: kelp forest and benthic invertebrate community dynamics following decades of sea otter expansion. | the recovery of predators has the potential to restore ecosystems and fundamentally alter the services they provide. one iconic example of this is keystone predation by sea otters in the northeast pacific. here, we combine spatial time series of sea otter abundance, canopy kelp area, and benthic invertebrate abundance from washington state, usa, to examine the shifting consequences of sea otter reintroduction for kelp and kelp forest communities. we leverage the spatial variation in sea otter re ... | 2018 | 30311056 |
| molecular characterization and prevalence of halarachne halichoeri in threatened southern sea otters (enhydra lutris nereis). | parasitism, particularly in concert with other sublethal stressors, may play an important, yet underappreciated role in morbidity and mortality of threatened species. during necropsy of southern sea otters (enhydra lutra nereis) from california submitted to the marine wildlife veterinary care and research center's sea otter necropsy program between 1999 and 2017, pathologists occasionally observed nasopulmonary mites infesting the respiratory tracts. infestation was sometimes accompanied by lesi ... | 2018 | 30370218 |
| measures of effective population size in sea otters reveal special considerations for wide-ranging species. | conservation genetic techniques and considerations of the evolutionary potential of a species are increasingly being applied to species conservation. for example, effective population size (ne) estimates are useful for determining the conservation status of species, yet accurate estimates of current ne remain difficult to obtain. the effective population size can contribute to setting federal delisting criteria, as was done for the southern sea otter (enhydra lutris nereis). after being hunted t ... | 2018 | 30459829 |
| mycoplasma enhydrae sp. nov. isolated from southern sea otters (enhydra lutris nereis). | five mycoplasma strains have been isolated from the oropharynx of southern sea otters (enhydra lutris nereis) from the central california coast, usa. these strains were phenotypically and genetically characterized and compared to other established mycoplasma species. all five strains hydrolysed arginine but not urea, but did not produce acid from glucose, and all were isolated and propagated under anaerobic and aerobic atmospheric conditions at +35-37 ˚c using either sp4 or pplo medium supplemen ... | 2019 | 30543510 |
| experiments reveal limited top-down control of key herbivores in southern california kelp forests. | predator responses to gradients in prey density have important implications for population regulation and are a potential structuring force for subtidal marine communities, particularly on rocky reefs where herbivorous sea urchins can drive community state shifts. on rocky reefs in southern california where predatory sea otters have been extirpated, top-down control of sea urchins by alternative predators has been hypothesized but rarely tested experimentally. in laboratory feeding assays, preda ... | 2019 | 30648729 |
| comparative ecology of bartonella and brucella infections in wild carnivores. | phylogenetic sister clades bartonella and brucella within the order rhizobiales present some common biological characteristics as well as evident differences in adaptations to their mammalian reservoirs. we reviewed published data on bartonella and brucella infections in wild carnivores to compare the ecology of these bacteria in relatively similar host environments. arthropod vectors are the main mechanism for bartonella species transmission between mammalian hosts. the role of arthropods in tr ... | 2018 | 30662899 |
| eye optics in semiaquatic mammals for aerial and aquatic vision. | based on anatomical measurements of refractive structures in the eye, the positions of focused images were computed for several groups of semiaquatic mammals: rodents, a nonpinniped semiaquatic carnivore (the sea otter), and pinniped carnivores (seals, sea lions, and the walrus). in semiaquatic rodents, eye optics enable emmetropia in the air but cause substantial hypermetropia in the water. in semiaquatic carnivores, there are several mechanisms for amphibious vision that focus images on the re ... | 2018 | 30799395 |
| wild sea otter mussel pounding leaves archaeological traces. | wild sea otters (enhydra lutris) are the only marine mammals that habitually use stones while foraging, using them to break open hard-shelled foods like marine snails and bivalves. however, the physical effects of this behavior on local environments are unknown. we show that sea otters pounding mussels on tidally emergent rocks leave distinct material traces, which can be recognized using methods from archaeology. we observed sea otters pounding mussels at the bennett slough culverts site, calif ... | 2019 | 30872658 |
| sex and occupation time influence niche space of a recovering keystone predator. | predators exert strong effects on ecological communities, particularly when they re-occupy areas after decades of extirpation. within species, such effects can vary over time and by sex and cascade across trophic levels. we used a space-for-time substitution to make foraging observations of sea otters (enhydra lutris) across a gradient of reoccupation time (1-30 years), and nonmetric multidimensional scaling (nmds) analysis to ask whether (a) sea otter niche space varies as a function of occupat ... | 2019 | 30962895 |
| pathology and epidemiology of nasopulmonary acariasis (halarachne sp.) in southern sea otters (enhydra lutris nereis). | halarachne sp. nasal mites infest harbor seals (phoca vitulina) and southern sea otters (enhydra lutris nereis) in california, but little is known about the pathophysiology of these infestations, or risk factors for exposure. to investigate these questions, a retrospective case-control study was performed using necropsy data from 70 mite-infested sea otters, and 144 non-infested controls. case records for sea otters examined by pathologists from february 1999 through may 2015 were examined to as ... | 2019 | 31011527 |
| there and back again - the return of the nasal mite halarachne halichoeri to seals in german waters. | the nasal mite halarachne halichoeri (acari; halarachnidae) is adapted to live in the marine environment with pinnipeds as its primary host and can cause different levels of upper respiratory disease in both harbour seals (phoca vitulina) and grey seals (halichoerus grypus). historical reports of h. halichoeri occurring in seals from german waters date back to the end of the 19th century. however, with the disappearance of the grey seal from german waters as a consequence of human over-exploitat ... | 2019 | 31061792 |
| the evolution of gametic compatibility and compatibility groups in the sea urchin mesocentrotus franciscanus: an avenue for speciation in the sea. | the generation of reproductive incompatibility between groups requires a rare genotype with low compatibility to increase in frequency. we tested the hypothesis that sexual conflict driven by the risk of polyspermy can generate compatibility groups in gamete recognition proteins (grps) in the sea urchin mesocentrotus franciscanus. we examined variation in the sperm (bindin) and egg (ebr1) grps, how this variation influences fertilization success and how allele frequencies shift in these grps ove ... | 2019 | 31125112 |
| aquatic adaptation and depleted diversity: a deep dive into the genomes of the sea otter and giant otter. | despite its recent invasion into the marine realm, the sea otter (enhydra lutris) has evolved a suite of adaptations for life in cold coastal waters, including limb modifications and dense insulating fur. this uniquely dense coat led to the near-extinction of sea otters during the 18th-20th century fur trade and an extreme population bottleneck. we used the de novo genome of the southern sea otter (e. l. nereis) to reconstruct its evolutionary history, identify genes influencing aquatic adaptati ... | 2019 | 31212313 |
| non-trophic impacts from white sharks complicate population recovery for sea otters. | complex interactions between protected populations may challenge the recovery of whole ecosystems. in california, white sharks (carcharodon carcharias) mistargeting southern sea otters (enhydra lutris nereis) are an emergent impact to sea otter recovery, inhibiting the broader ecosystem restoration sea otters might provide. here, we integrate and analyze tracking and stranding data to compare the phenology of interactions between white sharks and their targeted prey (elephant seals, mirounga ang ... | 2019 | 31236228 |
| trophic control of cryptic coralline algal diversity. | understanding how trophic dynamics drive variation in biodiversity is essential for predicting the outcomes of trophic downgrading across the world's ecosystems. however, assessing the biodiversity of morphologically cryptic lineages can be problematic, yet may be crucial to understanding ecological patterns. shifts in keystone predation that favor increases in herbivore abundance tend to have negative consequences for the biodiversity of primary producers. however, in nearshore ecosystems, cora ... | 2019 | 31285351 |
| concentrations of organohalogens (pcbs, ddts, pbdes) in hunted and stranded northern sea otters (enhydra lutris kenyoni) in alaska from 1992 to 2010: links to pathology and feeding ecology. | many organohalogen compounds (ohcs) are persistent organic pollutants (pops) found in appreciable concentrations in marine predators. while production of some pops has declined or ceased in recent decades, their capacity for global transport and bioaccumulation results in observations of unchanging or increasing concentrations in marine systems. sea otters (enhydra lutris) have been advocated as an environmental sentinel for contaminants due to their longevity, site fidelity and prey species tha ... | 2019 | 31326802 |
| type x strains of toxoplasma gondii are virulent for southern sea otters (enhydra lutris nereis) and present in felids from nearby watersheds. | why some toxoplasma gondii-infected southern sea otters (enhydra lutris nereis) develop fatal toxoplasmosis while others have incidental or mild chronic infections has long puzzled the scientific community. we assessed robust datasets on t. gondii molecular characterization in relation to detailed necropsy and histopathology results to evaluate whether parasite genotype influences pathological outcomes in sea otters that stranded along the central california coast. genotypes isolated from sea ot ... | 2019 | 31431162 |
| dry versus wet and gross: comparisons between the dry skull method and gross dissection in estimations of jaw muscle cross-sectional area and bite forces in sea otters. | bite force is a measure of feeding performance used to elucidate links between animal morphology, ecology, and fitness. obtaining live individuals for in vivo bite-force measurements or freshly deceased specimens for bite force modeling is challenging for many species. thomason's dry skull method for mammals relies solely on osteological specimens and, therefore, presents an advantageous approach that enables researchers to estimate and compare bite forces across extant and even extinct species. ... | 2019 | 31513299 |
| sea otters shown to have low genetic diversity. | 2019 | 31584653 | |
| seasonal and spatial variation in toxoplasma gondii contamination in soil in urban public spaces in california, united states. | toxoplasma gondii is a zoonotic parasite that can have severe implications for human health. acutely infected cats shed environmentally resistant t. gondii oocysts in their faeces that contaminate soil, and soil can serve as a reservoir of infection for humans. free-roaming domestic cats are thought to play an important role in environmental contamination with t. gondii, but few studies have directly measured the direct contribution of free-roaming cats to t. gondii in soil. | 2020 | 31677251 |
| viral emergence in marine mammals in the north pacific may be linked to arctic sea ice reduction. | climate change-driven alterations in arctic environments can influence habitat availability, species distributions and interactions, and the breeding, foraging, and health of marine mammals. phocine distemper virus (pdv), which has caused extensive mortality in atlantic seals, was confirmed in sea otters in the north pacific ocean in 2004, raising the question of whether reductions in sea ice could increase contact between arctic and sub-arctic marine mammals and lead to viral transmission acros ... | 2019 | 31700005 |
| species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries. | recovering species are often limited to much smaller areas than they historically occupied. conservation planning for the recovering species is often based on this limited range, which may simply be an artifact of where the surviving population persisted. southern sea otters (enhydra lutris nereis) were hunted nearly to extinction but recovered from a small remnant population on a remote stretch of the california outer coast, where most of their recovery has occurred. however, studies of recentl ... | 2019 | 31844568 |
| leptospirosis in northern sea otters (enhydra lutris kenyoni) from washington, usa. | we diagnosed leptospirosis in six northern sea otters (enhydra lutris kenyoni) that stranded on beaches in washington state, us in 2002. significant gross findings included cyanotic oral mucous membranes, renal swelling, congestion or pale streaks on the cut surface of renal lobules, hematuria, dehydration, lymphadenopathy, pulmonary congestion, and rarely adrenal hemorrhage and congestion. histopathology showed lymphoplasmacytic tubulointerstitial nephritis with intraluminal spirochetes and imm ... | 2020 | 31880990 |
| use of the acth challenge test to identify the predominant glucocorticoid in the southern sea otter (enhydra lutris nereis). | after nearly being hunted to extinction during the fur trade of the late 20th century, sea otter (enhydra lutris) populations have recovered to varying degrees of their historical range. while overall population numbers and range have increased, there are regions in which expansion has occurred at a slower rate and/or animal numbers have decreased, which may be a result of chronic stress from a variety of sources. some have employed glucocorticoid analysis in their attempts to validate these exp ... | 2020 | 32038847 |
| first draft genome of the sable, martes zibellina. | members of genus martes provide early warning signals about forest ecosystem health and are designated as a management indicator species. as one of the most widespread members in martes, the sable (martes zibellina) is a circumboreal small predator found throughout all taiga zoogeographical zones of eurasia and shows distinct population differentiation and morphological variations. to support further studies on striking local adaptation and population evolution, we present the first sable genome ... | 2020 | 32058545 |
| spatial epidemiological patterns suggest mechanisms of land-sea transmission for sarcocystis neurona in a coastal marine mammal. | sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (enhydra lutris nereis) after an outbreak in april 2004 and has since been detected in many marine mammal species in the northeast pacific ocean. risk of s. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. we examined the spatial distribution of s. neurona exposure risk based on serum antibody testing and assess ... | 2020 | 32111856 |
| novel infections of corynosoma enhydri and profilicollis sp. (acanthocephala: polymorphidae) identified in sea otters enhydra lutris. | infectious disease is a major cause of mortality for sea otters enhydra lutris, a keystone species of continued concern for conservationists. parasitic infection has long been identified as a cause of mortality in otters in both alaska and california, usa. corynosoma enhydri (acanthocephala) is the only parasite that uses sea otters as its primary definitive host and is highly prevalent in otter populations; however, it is generally considered unimportant both pathologically and ecologically, al ... | 2020 | 32132276 |
| primary intracranial fibrosarcoma in a southern sea otter enhydra lutris nereis. | southern sea otters enhydra lutris nereis, a threatened marine mammal species, face numerous environmental and infectious disease challenges in their native habitat of coastal california, usa. however, there are few published cases describing neoplasia in sea otters despite their relatively long life span when cared for in aquarium settings. an 18 yr old neutered male southern sea otter, born and raised in human care, presented with an acute onset of seizures and dull mentation. magnetic resonan ... | 2020 | 32213668 |
| long-term ecological impacts from oil spills: comparison of exxon valdez, hebei spirit, and deepwater horizon. | the long-term ecological impacts of the exxon valdez oil spill (evos) are compared to two extensively studied and more recent large spills: deepwater horizon (dwh) and the hebei spirit oil spill (hsos). each of the three spills differed in magnitude and duration of oil released, environmental conditions, ecological communities, response and clean up measures, and ecological recovery. the evos began on march 24, 1989, and released 40.8 million liters of alaska north slope crude oil into the cold, ... | 2020 | 32267150 |
| reductions in the dietary niche of southern sea otters (enhydra lutris nereis) from the holocene to the anthropocene. | the sea otter (enhydra lutris) is a marine mammal hunted to near extinction during the 1800s. despite their well-known modern importance as a keystone species, we know little about historical sea otter ecology. here, we characterize the ecological niche of ancient southern sea otters (e. lutris nereis) using δ13c analysis and δ15n analysis of bones recovered from archaeological sites spanning ~7,000 to 350 years before present (n = 112 individuals) at five regions along the coast of california. ... | 2020 | 32273989 |
| missing link: california rock crabs serve as intermediate hosts for the parasite helicometrina nimia. | parasites can have strong effects on invertebrate host behaviour, fecundity and survival in marine ecosystems. however, parasites are often poorly documented and still rarely integrated into marine ecological modelling; comprehensive surveys of infection in marine invertebrates are sporadic at best. for example, rock crabs are an important part of californian coastal ecosystems, both as regulators of mussel populations and non-native species, and as prey items for predators like sea otters, but ... | 2020 | 32281537 |
| cascading social-ecological costs and benefits triggered by a recovering keystone predator. | predator recovery often leads to ecosystem change that can trigger conflicts with more recently established human activities. in the eastern north pacific, recovering sea otters are transforming coastal systems by reducing populations of benthic invertebrates and releasing kelp forests from grazing pressure. these changes threaten established shellfish fisheries and modify a variety of other ecosystem services. the diverse social and economic consequences of this trophic cascade are unknown, par ... | 2020 | 32527830 |
| canine distemper virus in the sea otter (enhydra lutris) population in washington state, usa. | before 2001, all serosurveys for morbilliviruses in sea otters (enhydra lutris) in california, washington, and alaska, usa, documented a 0% seroprevalence. the first published serologic detections of morbillivirus in sea otters occurred in 2001-02 in live-captured washington sea otters, with a documented 80% seroprevalence. we conducted a retrospective study of sea otter cases from 1989 to 2010 compiled at the us geological survey, national wildlife health center to identify cases of morbillivir ... | 2020 | 32609600 |
| adaptations for amphibious vision in sea otters (enhydra lutris): structural and functional observations. | sea otters (enhydra lutris) are amphibious mammals that maintain equal in-air and underwater visual acuity. however, their lens-based underwater accommodative mechanism presumably requires a small pupil that may limit sensitivity across light levels. in this study, we consider adaptations for amphibious living by assessing the tapetum lucidum, retina, and pupil dynamics in sea otters. the sea otter tapetum lucidum resembles that of terrestrial carnivores in thickness and fundic coverage. a heavi ... | 2020 | 32666146 |
| olfaction at depth: cribriform plate size declines with dive depth and duration in aquatic arctoid carnivorans. | it is widely accepted that obligate aquatic mammals, specifically toothed whales, rely relatively little on olfaction. there is less agreement about the importance of smell among aquatic mammals with residual ties to land, such as pinnipeds and sea otters. field observations of marine carnivorans stress their keen use of smell while on land or pack ice. yet, one dimension of olfactory ecology is often overlooked: while underwater, aquatic carnivorans forage "noseblind," diving with nares closed, ... | 2020 | 32760503 |
| robust age estimation of southern sea otters from multiple morphometrics. | reliable age estimation is an essential tool to assess the status of wildlife populations and inform successful management. aging methods, however, are often limited by too few data, skewed demographic representation, and by single or uncertain morphometric relationships. in this study, we synthesize age estimates in southern sea otters enhydra lutris nereis from 761 individuals across 34 years of study, using multiple noninvasive techniques and capturing all life stages from 0 to 17 years of ag ... | 2020 | 32884643 |
| keystone predators govern the pathway and pace of climate impacts in a subarctic marine ecosystem. | predator loss and climate change are hallmarks of the anthropocene yet their interactive effects are largely unknown. here, we show that massive calcareous reefs, built slowly by the alga clathromorphum nereostratum over centuries to millennia, are now declining because of the emerging interplay between these two processes. such reefs, the structural base of aleutian kelp forests, are rapidly eroding because of overgrazing by herbivores. historical reconstructions and experiments reveal that ove ... | 2020 | 32913100 |
| isolation, characterization, and ecotoxicological application of marine mammal skin fibroblast cultures. | marine mammal cell cultures are a multifunctional instrument for acquiring knowledge about life in the world's oceans in physiological, biochemical, genetic, and ecotoxicological aspects. we succeeded in isolation, cultivation, and characterization of skin fibroblast cultures from five marine mammal species. the cells of the spotted seal (phoca largha), the sea lion (eumetopias jubatus), and the walrus (odobenus rosmarus) are unpretentious to the isolation procedure. the sea otter (enhydra lutri ... | 2020 | 33078324 |
| trophic downgrading reduces spatial variability on rocky reefs. | trophic downgrading in coastal waters has occurred globally during recent decades. on temperate rocky reefs, this has resulted in widespread kelp deforestation and the formation of sea urchin barrens. we hypothesize that the intact kelp forest communities are more spatially variable than the downgraded urchin barren communities, and that these differences are greatest at small spatial scales where the influence of competitive and trophic interactions is strongest. to address this, benthic commun ... | 2020 | 33093542 |