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a retrospective survey of the ocular histopathology of the pinniped eye with emphasis on corneal disease.a retrospective review of globes from 70 pinnipeds submitted to the comparative ocular pathology laboratory of wisconsin (coplow) describing the type and frequency of ocular disease.201322812701
endocrine changes in harbor seal (phoca vitulina) pups undergoing rehabilitation.rehabilitating pinniped pups are often admitted to care centers as neonates and generally lack maternal investment and are in poor body condition. upon admittance to a rehabilitation facility, pups are typically fed a milk replacement formula via gavage, which is switched to frozen fish upon weaning. while rehabilitation has been successful in terms of recovery and release, preweaning growth rates in captivity are consistently lower than in the wild. indicators of stress (cortisol and total thyr ...201322833416
biomagnification of polychlorinated biphenyls in a harbor seal (phoca vitulina) food web from the strait of georgia, british columbia, canada.polychlorinated biphenyl (pcb) biomagnification was characterized in a harbor seal food web in the strait of georgia, british columbia, canada. trophic magnification factors (tmfs) for pcbs averaged 3.6, with a range of 0.7 to 9.4. the tmfs for individual congeners correlated with log k(ow) (r(2) = 0.56, p < 0.001), reflecting the role that physicochemical properties play in driving the biomagnification of pcbs in marine food webs. however, tmfs differed among pcb structure activity groups, clea ...201222847788
emergence of fatal avian influenza in new england harbor seals.from september to december 2011, 162 new england harbor seals died in an outbreak of pneumonia. sequence analysis of postmortem samples revealed the presence of an avian h3n8 influenza a virus, similar to a virus circulating in north american waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. these include a d701n mutation in the viral pb2 protein, previously reported in highly pathogenic h5n1 avian influenza viruses infecting people. lectin staini ...201222851656
skin histology and its role in heat dissipation in three pinniped species.pinnipeds have a thick blubber layer and may have difficulty maintaining their body temperature during hot weather when on land. the skin is the main thermoregulatory conduit which emits excessive body heat.201222889205
natural selection on marine carnivores elaborated a diverse family of classical mhc class i genes exhibiting haplotypic gene content variation and allelic polymorphism.pinnipeds, marine carnivores, diverged from terrestrial carnivores ~45 million years ago, before their adaptation to marine environments. this lifestyle change exposed pinnipeds to different microbiota and pathogens, with probable impact on their mhc class i genes. investigating this question, genomic sequences were determined for 71 mhc class i variants: 27 from harbor seal and 44 from gray seal. these variants form three mhc class i gene lineages, one comprising a pseudogene. the second, a can ...201223001684
hair sampling location in harbor seals (phoca vitulina) affects selenium and mercury concentrations: implications for study design of trace element determination in pinnipeds.hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. the objective of this study was to determine whether concentrations of an essential (selenium; se) and non-essential element (mercury; hg) differed between hair samples collected from two body locati ...201223017952
temporal processing of low-frequency sounds by seals (l).in a recent study, kastelein et al. [(2010) j. acoust. soc. am. 127, 1135-1145] reported auditory integration times for harbor seals (phoca vitulina) exceeding 3000 ms for 200 hz tonal signals. this finding is unexpected and potentially significant given that time constants measured in mammals for tones above 1 khz are typically less than 500 ms. to further explore this result, the hearing of another harbor seal was measured in air and water for 200 hz tones with durations of 500 and 2500 ms. th ...201223039406
hearing threshold shifts and recovery in harbor seals (phoca vitulina) after octave-band noise exposure at 4 khz.safety criteria for underwater sounds from offshore pile driving are needed to protect marine mammals. as a first step toward understanding effects of impulsive sounds, two harbor seals were exposed to octave-band white noise centered at 4 khz at three mean received sound pressure levels (spls; 124, 136, and 148 db re 1 μpa) at up to six durations (7.5, 15, 30, 60, 120, and 240 min); mean received sound exposure level (sel) range was 166-190 db re 1 μpa(2) s. hearing thresholds were determined b ...201223039466
mortality related to spotted ratfish (hydrolagus colliei) in pacific harbor seals (phoca vitulina) in washington state.tissue perforation and penetration by dorsal fin spines of spotted ratfish (hydrolagus colliei) were responsible for the death of seven harbor seals (phoca vitulina) in washington state (usa) between 2006 and 2011. in six animals, necropsy revealed spines or spine parts that had perforated the esophagus or stomach and migrated into vital tissues, resulting in hemothorax, pneumothorax, pleuritis, and peritonitis. in a seventh case, a ratfish spine was recovered from the mouth of a harbor seal eut ...201223060509
the effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (phoca vitulina).many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. this discrepancy is most likely due to an overestimation of diving metabolic rate. during diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism). thyroid hormones are crucial in regulation of energy metabol ...201223060807
are harbour seals (phoca vitulina) able to perceive and use polarised light?harbour seals are active at night and during the day and see well in both air and water. polarised light, which is a well-known visual cue for orientation, navigation and foraging, is richly available in harbour seal habitats, both above and below the water surface. we hypothesised that an ability to detect and use polarised light could be valuable for seals, and thus tested if they are able to see this property of light. we performed two behavioural experiments, one involving object discriminat ...201323076442
erysipelothrix rhusiopathiae isolates recovered from fish, a harbour seal (phoca vitulina) and the marine environment are capable of inducing characteristic cutaneous lesions in pigs.in order to determine the diversity and pathogenicity of erysipelothrix spp. isolates recovered from marine fish, a harbour seal (phoca vitulina) and the marine environment, 14 isolates were characterized by genotyping, serotyping, determination of the surface protective antigen (spa) gene type and assessment of virulence in a pig bioassay. all 14 isolates were erysipelothrix rhusiopathiae. isolates were determined to be of serotypes 2 (n = 3), 3 (n = 1), 4 (n = 1), 12 (n = 1), 15 (n = 1) or 21 ...201323083834
hydrodynamic perception in true seals (phocidae) and eared seals (otariidae).pinnipeds, that is true seals (phocidae), eared seals (otariidae), and walruses (odobenidae), possess highly developed vibrissal systems for mechanoreception. they can use their vibrissae to detect and discriminate objects by direct touch. at least in phocidae and otariidae, the vibrissae can also be used to detect and analyse water movements. here, we review what is known about this ability, known as hydrodynamic perception, in pinnipeds. hydrodynamic perception in pinnipeds developed convergen ...201323180048
dolphin morbillivirus infection in a captive harbor seal (phoca vitulina).during the second morbillivirus epidemic (2007 to 2011) in cetaceans along the italian coastline, dolphin morbillivirus (dmv) was detected by molecular analyses in a captive harbor seal (phoca vitulina), with pathological findings consistent with morbillivirus infection. this report confirms interspecies dmv transmission from cetaceans to pinnipeds.201323224101
plastic ingestion by harbour seals (phoca vitulina) in the netherlands.abundance of ingested debris by seals has been mentioned as a potential indicator of marine litter in the european marine strategy framework directive (msfd). a sample of 107 stomachs, 100 intestines and 125 scats of harbour seals from the netherlands was analysed for the presence of plastics. incidence of plastic was 11% for stomachs, 1% for intestines, and 0% for scats. younger animals, up to 3 years of age, were most affected. this is the first quantitative study of plastic ingestion by phoci ...201323245459
occurrence of pasteurellaceae bacteria in the oral cavity of selected marine mammal species.the occurrence of bacteria belonging to pasteurellaceae in the oral cavity of captive marine mammals was investigated using culture and subsequent geno- and phenotypic characterization and phylogenetic analyses. a total of 89 bacterial isolates from pinnipeds tentatively classified with the family pasteurellaceae were further characterized by phylogenetic analysis of rpob gene sequences, which showed that the isolates investigated formed five distinct groups. four strains from california sea lio ...201223272350
assay dependence of brucella antibody prevalence in a declining alaskan harbor seal (phoca vitulina) population.brucella is a group of bacteria that causes brucellosis, which can affect population health and reproductive success in many marine mammals. we investigated the serological prevalence of antibodies against brucella bacteria in a declining harbor seal population in glacier bay national park, alaska.201323324565
dynamics of vibrio with virulence genes detected in pacific harbor seals (phoca vitulina richardii) off california: implications for marine mammal health.given their coastal site fidelity and opportunistic foraging behavior, harbor seals (phoca vitulina) may serve as sentinels for coastal ecosystem health. seals using urbanized coastal habitat can acquire enteric bacteria, including vibrio that may affect their health. to understand vibrio dynamics in seals, demographic and environmental factors were tested for predicting potentially virulent vibrio in free-ranging and stranded pacific harbor seals (phoca vitulina richardii) off california. vibri ...201323392641
vibrissal touch sensing in the harbor seal (phoca vitulina): how do seals judge size?"whisker specialists" such as rats, shrews, and seals actively employ their whiskers to explore their environments and extract object properties such as size, shape, and texture. it has been suggested that whiskers could be used to discriminate between different sized objects in one of two ways: (i) to use whisker positions, such as angular position, spread or amplitude to approximate size; or (ii) to calculate the number of whiskers that contact an object. this study describes in detail how two ...201323397461
post-breeding season migrations of a top predator, the harbor seal (phoca vitulina richardii), from a marine protected area in alaska.marine protected areas (mpas) are increasingly being used as a conservation tool for highly mobile marine vertebrates and the focus is typically on protecting breeding areas where individuals are aggregated seasonally. yet movements during the non-breeding season can overlap with threats that may be equally as important to population dynamics. thus understanding habitat use and movements of species during the non-breeding periods is critical for conservation. glacier bay national park, alaska, i ...201323457468
detection of canine distemper virus serum neutralizing antibodies in captive u.s. phocids.antibodies to morbilliviruses have been documented in free-ranging pinnipeds throughout populations in the atlantic and arctic oceans, but not from the pacific ocean. as a symbolic geographic barrier between the exposed atlantic and naive pacific populations, the captive phocid population in north america had undocumented serologic status. in this study, canine distemper virus (cdv) serum neutralization assays were used to assess the prevalence of antibodies in this population with participation ...201323505705
brightness discrimination in the south african fur seal (arctocephalus pusillus).underwater, the contrast between object and background is much larger reduced with increasing distance between object and observer than in air. for marine predators, such as pinnipeds, it would therefore be advantageous to possess a high sensitivity for brightness differences, since this would increase the distance at which prey can be detected visually. few studies have examined the brightness discrimination thresholds of pinnipeds. two studies with phocid seals have confirmed low brightness di ...201323506966
pfas profiles in three north sea top predators: metabolic differences among species?profiles of seven compounds of perfluoro-alkyl substances (pfass) were compared among three species of top predators from the danish north sea: the white-beaked dolphin (lagenorhynchus albirostris), the harbor porpoise (phocoena phocoena), and the harbor seal (phoca vitulina). the seals had higher total burdens (757.8 ng g(-1) ww) than the dolphins (439.9 ng g(-1) ww) and the porpoises (355.8 ng g(-1) ww), probably a reflection of feeding closer to the shore and thus contamination sources. the m ...201323532533
a harbor seal can transfer the same/different concept to new stimulus dimensions.we investigated the formation of an abstract concept of same/different in a harbor seal by means of a two-item same/different task. stimuli were presented on a tft monitor. the subject was trained to respond according to whether two horizontally aligned white shapes presented on a black background were the same, or different from each other, by giving a no-go or go response. training comprised of four stages. first, the same/different task was trained with two shapes forming two same problems (a ...201323535852
comparative assessment of amphibious hearing in pinnipeds.auditory sensitivity in pinnipeds is influenced by the need to balance efficient sound detection in two vastly different physical environments. previous comparisons between aerial and underwater hearing capabilities have considered media-dependent differences relative to auditory anatomy, acoustic communication, ecology, and amphibious life history. new data for several species, including recently published audiograms and previously unreported measurements obtained in quiet conditions, necessita ...201323563644
phocine herpesvirus 1 (phhv-1) in harbor seals from svalbard, norway.phocine herpesvirus 1 (phhv-1) infections in seals are associated with disease and sometimes high mortality, primarily in young animals. phhv-1 has been detected in seals from european waters as well as in waters on both coasts of north america. serological surveys of various pinniped species have indicated a wide geographical distribution of phhv-1. a quantitative and sensitive real-time pcr assay targeting the gene encoding glycoprotein b of phhv-1 was developed for detection of phhv-1 in ocul ...201323570865
quantifying sequence proportions in a dna-based diet study using ion torrent amplicon sequencing: which counts count?a goal of many environmental dna barcoding studies is to infer quantitative information about relative abundances of different taxa based on sequence read proportions generated by high-throughput sequencing. however, potential biases associated with this approach are only beginning to be examined. we sequenced dna amplified from faeces (scats) of captive harbour seals (phoca vitulina) to investigate whether sequence counts could be used to quantify the seals' diet. seals were fed fish in fixed p ...201323590207
serologic response of harbor seals (phoca vitulina) to vaccination with a recombinant canine distemper vaccine.morbilliviruses pose a significant threat to marine mammal populations around the world and have been associated with multiple epizootics in pinnipeds and cetaceans. as part of a preventive veterinary medical program, five harbor seals (phoca vitulina) in a managed collection were vaccinated with a recombinant canarypox-vectored canine distemper virus vaccine. the vaccine was evaluated for safety (by monitoring seals for local and systemic adverse effects and by testing for shedding of the canar ...201323778607
otariodibacter oris and bisgaardia genomospecies 1 isolated from infections in pinnipeds.we document the first associations of two recently described species of pasteurellaceae bacteria with lesions in wild pinnipeds in rehabilitation. samples were collected from nine lesions in four california sea lions (zalophus californianus) and two pacific harbor seals (phoca vitulina) during necropsy or admission examinations at a rehabilitation facility in northern california. seven pasteurellaceae isolates were identified using phenotypic tests and partial rpob gene sequencing. six strains o ...201323778617
infection due to mycobacterium avium subsp. avium in a free-ranging common seal (phoca vitulina) in scotland.we describe the first reported case of mycobacterial infection in a free-ranging pinniped in the northern hemisphere. acid-fast bacteria were demonstrated histologically in the liver of an adult female common seal (phoca vitulina), and mycobacterium avium subsp. avium was cultured from the liver.201323778632
variation in breeding phenology provides insights into drivers of long-term population change in harbour seals.phenological trends provide important indicators of environmental change and population dynamics. however, the use of untested population-level measures can lead to incorrect conclusions about phenological trends, particularly when changes in population structure or density are ignored. we used individual-based estimates of birth date and lactation duration of harbour seals (phoca vitulina) to investigate energetic consequences of changes in pupping phenology. using generalized linear mixed mode ...201323782881
complete genome sequence of phocine distemper virus isolated from a harbor seal (phoca vitulina) during the 1988 north sea epidemic.phocine distemper virus (pdv) was identified as the cause of a large morbillivirus outbreak among harbor seals in the north sea in 1988. pdv is a member of the family paramyxoviridae, genus morbillivirus. until now, no full-genome sequence of pdv has been available.201323814028
the world's northernmost harbour seal population-how many are there?this study presents the first abundance estimate for the world's northernmost harbour seal (phoca vitulina) population, which resides in svalbard, norway, based on three digital stereoscopic photographic surveys conducted in 2009 and 2010. the counts from these high resolution 3d images were combined with a novel method for estimating correction factors for animals that were in the water at the time of the surveys, in which extensive behavioural data from radio-tagged harbour seals were used tog ...201323844035
comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal.anthropogenic noise may cause temporary hearing threshold shifts (ttss) in marine mammals. tests with identical methods show that harbor porpoises are more susceptible to tts induced by octave-band white noise (obn) centered around 4 khz than harbor seals, although their unmasked (basic) hearing thresholds for that frequency are similar. a harbor seal was exposed for 1 h to an obn with a very high sound pressure level (spl), 22-30 db above levels causing tts onset. this elicited 44 db tts; heari ...201323862780
immune status and function in harbor seal pups during the course of rehabilitation.routine hematological and serum chemistry parameters are important tools for the evaluation of health and the treatment of marine mammals admitted to rehabilitation centers. the evaluation of phagocytosis, oxidative burst and immunoglobulin g (igg), as markers of immune system function, and haptoglobin (hp), as a stress marker, were evaluated alongside routine hematology and chemistry as potentially informative diagnostic tools for marine mammal health assessments. blood samples from harbor seal ...201323866720
the use of non destructive biomarkers in the study of marine mammals.marine mammals have been subject to heavy anthropogenic pressure by direct killing and chemical pollution all over the world. most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting out of a total of 12 cetacean species studied, 45 of the specimens were obtained by sacrificing the animal; out of a total of eight pinniped species studied, 40 of the specimens were obtained by killing. the development of a series of non destructive ...199723899212
effect of angle on flow-induced vibrations of pinniped vibrissae.two types of vibrissal surface structures, undulated and smooth, exist among pinnipeds. most phocidae have vibrissae with undulated surfaces, while otariidae, odobenidae, and a few phocid species possess vibrissae with smooth surfaces. variations in cross-sectional profile and orientation of the vibrissae also exist between pinniped species. these factors may influence the way that the vibrissae behave when exposed to water flow. this study investigated the effect that vibrissal surface structur ...201323922834
entry and elimination of marine mammal brucella spp. by hooded seal (cystophora cristata) alveolar macrophages in vitro.a high prevalence of brucellapinnipedialis serology and bacteriology positive animals has been found in the northeast atlantic stock of hooded seal (cystophoracristata); however no associated gross pathological changes have been identified. marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. to investigate if marine mammal brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveol ...201323936159
tracking niche variation over millennial timescales in sympatric killer whale lineages.niche variation owing to individual differences in ecology has been hypothesized to be an early stage of sympatric speciation. yet to date, no study has tracked niche width over more than a few generations. in this study, we show the presence of isotopic niche variation over millennial timescales and investigate the evolutionary outcomes. isotopic ratios were measured from tissue samples of sympatric killer whale orcinus orca lineages from the north sea, spanning over 10 000 years. isotopic rati ...201323945688
hearing thresholds of two harbor seals (phoca vitulina) for playbacks of multiple pile driving strike sounds.pile driving, which creates high amplitude sounds with potentially negative impacts on the marine environment, is used to attach wind turbines to the sea bed. to quantify the distance at which pile driving sounds can be detected by harbor seals, unmasked hearing thresholds were obtained for series of five pile driving sounds recorded at 100 and 800 m from a pile driving location. the played back spectra resembled the spectra of sounds recorded under certain conditions 10-50 km from an offshore p ...201323967961
immune-relevant and new xenobiotic molecular biomarkers to assess anthropogenic stress in seals.harbour seals as top predators and indicators for ecosystem health are exposed to increasing pressure caused by anthropogenic activities in their marine environment. after their lactation period of about 24 days pups are weaned and left to hunt on their own. little is known about the development of their immune system and a better understanding of anthropogenic impacts on the general health and immune system of harbour seal pups is needed. mrna transcription of six immuno-relevant biomarkers was ...201324025588
state-space modelling reveals proximate causes of harbour seal population declines.declines in large vertebrate populations are widespread but difficult to detect from monitoring data and hard to understand due to a multiplicity of plausible biological explanations. in parts of scotland, harbour seals (phoca vitulina) have been in decline for 10 years. to evaluate the contributions of different proximate causes (survival, fecundity, observation artefacts) to this decline, we collated behavioural, demographic and population data from one intensively studied population in part o ...201424036987
relationships between in vitro lymphoproliferative responses and levels of contaminants in blood of free-ranging adult harbour seals (phoca vitulina) from the north sea.in vitro culture of peripheral blood leucocytes (pbls) is currently used in toxicological studies of marine mammals. however, blood cells of wild individuals are exposed in vivo to environmental contaminants before being isolated and exposed to contaminants in vitro. the aim of this study was to highlight potential relationships between blood contaminant levels and in vitro peripheral blood lymphocyte proliferation in free-ranging adult harbour seals (phoca vitulina) from the north sea. blood sa ...201324051082
pelodera strongyloides infection in pacific harbor seals (phoca vitulina richardii) from california.skin biopsies were collected from free-ranging harbor seals (phoca vitulina richardii) from central california (n = 53). microscopic examination of hematoxylin and eosin-stained tissue sections revealed the presence of tightly coiled nematode larvae within the ostia of numerous hair follicles of four seals. parasites were characterized by paired lateral alae, platymyarian musculature, and an indistinct, uninucleate digestive tract. mild chronic superficial dermatitis and perifolliculitis were ev ...201324063118
clinical evaluation and biochemical analyses of thiamine deficiency in pacific harbor seals (phoca vitulina) maintained at a zoological facility.to determine thiamine-dependent enzyme activities in various tissue samples of pacific harbor seals (phoca vitulina) and thiaminase activities in dietary fish.201324094267
improving accuracy of dna diet estimates using food tissue control materials and an evaluation of proxies for digestion bias.ecologists are increasingly interested in quantifying consumer diets based on food dna in dietary samples and high-throughput sequencing of marker genes. it is tempting to assume that food dna sequence proportions recovered from diet samples are representative of consumer's diet proportions, despite the fact that captive feeding studies do not support that assumption. here, we examine the idea of sequencing control materials of known composition along with dietary samples in order to correct for ...201424102760
novel b19-like parvovirus in the brain of a harbor seal.using random pcr in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the seal rehabilitation and research centre (srrc) in the netherlands. in addition, two novel viruses belonging to the family anelloviridae were detected in the lungs of this animal. phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called se ...201324223918
beneath the surface: profiling blubber depth in pinnipeds with infrared imaging.infrared thermography (irt) was assessed as a non-invasive tool to evaluate body condition in juvenile female harbor seals (phoca vitulina), (n=6) and adult female steller sea lions (eumetopias jubatus), (n=2). surface temperature determined by irt and blubber depth assessed with portable imaging ultrasound were monitored concurrently at eight body sites over the course of a year in long-term captive individuals under controlled conditions. site-specific differences in surface temperature were n ...201324229798
a comparative analysis of marine mammal tracheas.in 1940, scholander suggested that stiffened upper airways remained open and received air from highly compressible alveoli during marine mammal diving. there are few data available on the structural and functional adaptations of the marine mammal respiratory system. the aim of this research was to investigate the anatomical (gross) and structural (compliance) characteristics of excised marine mammal tracheas. here, we defined different types of tracheal structures, categorizing pinniped tracheas ...201424311807
pup mortality in a rapidly declining harbour seal (phoca vitulina) population.the harbour seal population in orkney, off the north coast of scotland, has reduced by 65% between 2001 and 2010. the cause(s) of this decline are unknown but must affect the demographic parameters of the population. here, satellite telemetry data were used to test the hypothesis that increased pup mortality could be a primary driver of the decline in orkney. pup mortality and tag failure parameters were estimated from the duration of operation of satellite tags deployed on harbour seal pups fro ...201324312239
linking reproduction and survival can improve model estimates of vital rates derived from limited time-series counts of pinnipeds and other species.we propose a method to model the physiological link between somatic survival and reproductive output that reduces the number of parameters that need to be estimated by models designed to determine combinations of birth and death rates that produce historic counts of animal populations. we applied our reproduction and somatic survival linked (rssl) method to the population counts of three species of north pacific pinnipeds (harbor seals, phoca vitulina richardii (gray, 1864); northern fur seals, ...201324324541
integrating genetic data and population viability analyses for the identification of harbour seal (phoca vitulina) populations and management units.identification of populations and management units is an essential step in the study of natural systems. still, there is limited consensus regarding how to define populations and management units, and whether genetic methods allow for inference at the relevant spatial and temporal scale. here, we present a novel approach, integrating genetic, life history and demographic data to identify populations and management units in southern scandinavian harbour seals. first, 15 microsatellite markers and ...201424382213
unfolding simulations of holomyoglobin from four mammals: identification of intermediates and β-sheet formation from partially unfolded states.myoglobin (mb) is a centrally important, widely studied mammalian protein. while much work has investigated multi-step unfolding of apomb using acid or denaturant, holomyoglobin unfolding is poorly understood despite its biological relevance. we present here the first systematic unfolding simulations of holomb and the first comparative study of unfolding of protein orthologs from different species (sperm whale, pig, horse, and harbor seal). we also provide new interpretations of experimental mea ...201324386077
haul-out behaviour of the world's northernmost population of harbour seals (phoca vitulina) throughout the year.the harbour seal population in svalbard occurs at the northernmost limit of the species' range. it experiences environmental extremes far beyond the norm for this species, including an extended period of polar night and extensive sea ice cover. in 2009 and 2010, 60 harbour seals (30 pups + 30 immature/mature seals) from this population were equipped with satellite-relay data loggers (srdls) to study their haul-out behaviour, with a special focus on the winter period. using a combination of gener ...201424465867
feeding kinematics, suction, and hydraulic jetting performance of harbor seals (phoca vitulina).the feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (phoca vitulina) were characterized during controlled feeding trials. feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. the mean feeding cycle duration for suction-feeding events ...201424475170
use of cellulose filter paper to quantify whole-blood mercury in two marine mammals: validation study.whole blood (wb) is commonly used to assess mercury (hg) exposure in mammals, but handling and shipping samples collected in remote areas can be difficult. we describe and validate use of cellulose filter paper (fp) for quantifying wb total hg concentration. advantec nobuto® fp was soaked with bottlenose dolphin (tursiops truncatus) or harbor seal (phoca vitulina) wb (collected between march and july 2012), then air dried. untreated blood-soaked fps were analyzed or were eluted with phosphate-bu ...201424484499
validation of an enzyme-linked immunoassay (elisa) for plasma oxytocin in a novel mammal species reveals potential errors induced by sampling procedure.the neuropeptide oxytocin is increasingly the focus of many studies investigating human and animal social behaviours and diseases. however, interpretation and comparison of results is made difficult by a lack of consistent methodological approaches towards analysing this hormone.201424485867
analysis of blood gases, serum fat and serum protein: a new approach to estimate survival chances of stranded harbor seal (phoca vitulina) pups from the german north sea.facing numerous challenges, such as illness, storms or human disturbance, some harbor seal (phoca vitulina) pups lose contact to their dams and are found abandoned along the north sea coast. in schleswig-holstein, pups with the prospect of surviving rehabilitation are admitted to the seal center friedrichskoog. despite elaborate clinical health assessments on admission, including differential hematology, in 2010, 17% of 108 admitted pups did not survive the first 20 days. the death rate during t ...201424490584
brucella pinnipedialis infections in pacific harbor seals (phoca vitulina richardsi) from washington state, usa.in 1994 a novel brucella sp., later named b. pinnipedialis, was identified in stranded harbor seals (phoca vitulina). this brucella sp. is a potential zoonotic pathogen and is capable of causing disease in domestic animals. serologic, microbiologic, and pathologic data collected from live captured and stranded harbor seals were used to better describe the epizootiology of b. pinnipedialis in harbor seals from washington state, usa, in 1994 through 2006. we found no sex predilection in harbor sea ...201324502708
influenza a virus infections in marine mammals and terrestrial carnivores.influenza a viruses (iav), members of the orthomyxoviridae, cover a wide host spectrum comprising a plethora of avian and, in comparison, a few mammalian species. the viral reservoir and gene pool are kept in metapopulations of aquatic wild birds. the mammalian-adapted iavs originally arose by transspecies transmission from avian sources. in swine, horse and man, species-adapted iav lineages circulate independently of the avian reservoir and cause predominantly respiratory disease of highly vari ...201424511825
anisakids of seals found on the southern coast of baltic sea.in the present study 5 grey seals (halichoerus grypus), 3 common seals (phoca vitulina) and 1 ringed seal (pusa hispida) bycaught or stranded on the polish baltic sea coast in years 2000-2006 were investigated for the infestation of parasitic anisakid nematodes. 749 of anisakids were found. the most common were: contracaecum osculatum (59.3%) and pseudoterranova decipiens (31.0%). there were also small numbers of anisakis simplex (0.8%). after performing rflp three sibling species were found. c. ...201424570064
amphibious hearing in spotted seals (phoca largha): underwater audiograms, aerial audiograms and critical ratio measurements.spotted seals (phoca largha) inhabit arctic regions that are facing both rapid climate change and increasing industrialization. while little is known about their sensory capabilities, available knowledge suggests that spotted seals and other ice seals use sound to obtain information from the surrounding environment. to quantitatively assess their auditory capabilities, the hearing of two young spotted seals was tested using a psychophysical paradigm. absolute detection thresholds for tonal sound ...201424574387
temporal records of δ(13)c and δ (15)n in north pacific pinnipeds: inferences regarding environmental change and diet.sea lion and seal populations in alaskan waters underwent various degrees of decline during the latter half of the twentieth century and the cause(s) for the declines remain uncertain. the stable carbon ((13)c/(12)c) and nitrogen ((15)n/(14)n) isotope ratios in bone collagen from wild steller sea lions (eumetopias jubatus), northern fur seals (callorhinus ursinus) and harbor seals (phoca vitulina) from the bering sea and gulf of alaska were measured for the period 1951-1997 to test the hypothesi ...200124577700
high-throughput sequencing reveals inbreeding depression in a natural population.proxy measures of genome-wide heterozygosity based on approximately 10 microsatellites have been used to uncover heterozygosity fitness correlations (hfcs) for a wealth of important fitness traits in natural populations. however, effect sizes are typically very small and the underlying mechanisms remain contentious, as a handful of markers usually provides little power to detect inbreeding. we therefore used restriction site associated dna (rad) sequencing to accurately estimate genome-wide hete ...201424586051
stomach temperature records reveal nursing behaviour and transition to solid food consumption in an unweaned mammal, the harbour seal pup (phoca vitulina).knowledge of milk transfer from mother to offspring and early solid food ingestions in mammals allows for a greater understanding of the factors affecting transition to nutritional independence and pre-weaning growth and survival. yet studies monitoring suckling behaviour have often relied on visual observations, which might not accurately represent milk intake. we assessed the use of stomach temperature telemetry to monitor suckling and foraging behaviour in free-ranging harbour seal (phoca vit ...201424587327
assessing performance of bayesian state-space models fit to argos satellite telemetry locations processed with kalman filtering.argos recently implemented a new algorithm to calculate locations of satellite-tracked animals that uses a kalman filter (kf). the kf algorithm is reported to increase the number and accuracy of estimated positions over the traditional least squares (ls) algorithm, with potential advantages to the application of state-space methods to model animal movement data. we tested the performance of two bayesian state-space models (ssms) fitted to satellite tracking data processed with kf algorithm. trac ...201424651252
fine-scale variability in harbor seal foraging behavior.understanding the variability of foraging behavior within a population of predators is important for determining their role in the ecosystem and how they may respond to future ecosystem changes. however, such variability has seldom been studied in harbor seals on a fine spatial scale (<30 km). we used a combination of standard and bayesian generalized linear mixed models to explore how environmental variables influenced the dive behavior of harbor seals. time-depth recorders were deployed on har ...201424717815
what a jerk: prey engulfment revealed by high-rate, super-cranial accelerometry on a harbour seal (phoca vitulina).a key component in understanding the ecological role of marine mammal predators is to identify how and where they capture prey in time and space. satellite and archival tags on pinnipeds generally only provide diving and position information, and foraging is often inferred to take place in particular shaped dives or when the animal remains in an area for an extended interval. however, fast movements of the head and jaws may provide reliable feeding cues that can be detected by small low-power ac ...201424737765
selenium and mercury concentrations in harbor seals (phoca vitulina) from central california: health implications in an urbanized estuary.we measured total selenium and total mercury concentrations ([tse] and [thg]) in hair (n=138) and blood (n=73) of harbor seals (phoca vitulina) from california to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. harbor seals from hg-contaminated sites had significantly greater [thg], and lesser [tse] and tse:thg molar ratios than seals from a relatively uncontaminated site. males had significantly greater [thg] than ...201424823685
validation of a commercial canine assay kit to measure pinniped cytokines.the present study was conducted to assess and validate the cross-reactivity of commercially available multiplex human and canine cytokine kits coupled with the bio-plex 200 platform to measure cytokines in three pinniped species, harbor seals (phoca vitulina), gray seals (halichoerus grypus), and harp seals (pagophilus groenlandicus). cytokines are important small proteins that help direct a proper immune response to pathogens. the human cytokine kit allowed the detection of cytokines in the sup ...201424845148
mechanical characteristics of harbor seal (phoca vitulina) vibrissae under different circumstances and their implications on its sensing methodology.in this paper, the mechanical properties of harbor seal vibrissae immersed in various solutions are investigated. as there are no nerves along the length of the vibrissae, all the perturbations have to be transmitted to their bases for sensing. hence, quantification and understanding of the mechanical properties of the vibrissae are essential in determining the perturbations transmitted to the base of the vibrissae. two experimental setups are devised for measurements of the different properties ...201424871073
polychlorinated biphenyls still pose significant health risks to northwest atlantic harbor seals.polychlorinated biphenyls (pcbs) have been detected at relatively high concentrations in harbor seals, apex predators in the northwest atlantic. as part of an ongoing assessment of the effects of pcbs on population health, we analyzed tri- to deca-pcbs in the liver of 56 harbor seals (6 adult males, 50 pups) and in 11 blubber samples (4 adult males, 7 pups) and examined tissue-specific accumulation patterns, biomagnification potential, and toxic implications of current pcb concentrations. hepati ...201424875260
interactions of marine mammals and birds with offshore membrane enclosures for growing algae (omega).omega is an integrated aquatic system to produce biofuels, treat and recycle wastewater, capture co2, and expand aquaculture production. this system includes floating photobioreactors (pbrs) that will cover hundreds of hectares in marine bays. to assess the interactions of marine mammals and birds with pbrs, 9 × 1.3 m flat panel and 9.5 × 0.2 m tubular pbrs were deployed in a harbor and monitored day and night from october 10, 2011 to janurary 22, 2012 using infrared video. to observe interactio ...201424955238
methoxylated pbdes (meo-pbdes), hydroxylated pbdes (ho-pbdes) and hydroxylated pcbs (ho-pcbs) in the liver of harbor seals from the northwest atlantic.metabolites of pcbs and pbdes are shown to influence the thyroid hormone homeostasis and therefore, could have an influence on the growth of newborn or young animals. we have investigated the occurrence of hydroxylated pcbs (ho-pcbs), hydroxylated pbdes (ho-pbdes), and methoxylated pbdes (meo-pbdes) in the liver (48 pups; 6 adults) and blubber (4 pups; 1 adult) of harbor seals (phoca vitulina concolor) from the northwest atlantic. the sum of ho-pcbs in the liver ranged from 90 to 22,450 pg/g wet ...201424982026
length of intervals between epidemics: evaluating the influence of maternal transfer of immunity.the length of intervals between epidemic outbreaks of infectious diseases is critical in epidemiology. in several species of marine mammals and birds, it is pivotal to also consider the life history of the species of concern, as the contact rate between individuals can have a seasonal flux, for example, due to aggregations during the breeding season. recently, particular interest has been given to the role of the dynamics of immunity in determining the intervals between epidemics in wild animal ...201425035798
harbor seals (phoca vitulina) can perceive optic flow under water.optic flow, the pattern of apparent motion elicited on the retina during movement, has been demonstrated to be widely used by animals living in the aerial habitat, whereas underwater optic flow has not been intensively studied so far. however optic flow would also provide aquatic animals with valuable information about their own movement relative to the environment; even under conditions in which vision is generally thought to be drastically impaired, e. g. in turbid waters. here, we tested unde ...201425058490
contaminant levels in the world's northernmost harbor seals (phoca vitulina).the world's northernmost harbor seal (phoca vitulina) population, which inhabits svalbard, norway, constitutes a genetically distinct population. the present study reports concentrations of 14 pcbs, 5 chlordanes, p,p'-ddt, p,p'-dde, hexachlorobenzene (hcb), mirex, and, α-, β-and γ-hexachlorocyclohexane (hch) in blubber, and pentachlorophenol, 4-oh-heptachlorostyrene, 10 oh-pcbs and 14 perfluoroalkyl substances in plasma of live-captured harbor seals from this population (4 males, 4 females, 4 ju ...201425152181
effects and risk evaluation of oil spillage in the sea areas of changxing island.this paper evaluated the oil spillage risk in the waters near the island of changxing in dalian (china) based on the established risk assessment index. four wind regimes (windless, northerly wind, westerly wind and southerly wind) were selected as weather conditions for the dynamic prediction of oil drift. if an oil spill occurs near the koumen (a place near the island of changxing), the forecast and evaluation are conducted based on a three-dimensional mathematical model of oil spillage, and th ...201425153473
variable transcription of pro- and anti-inflammatory cytokines in phocine lymphocytes following canine distemper virus infection.canine distemper virus (cdv) is a highly contagious viral pathogen. domesticated dogs are the main reservoir of cdv. although phocine distemper virus was responsible for the recent epidemics in seals in the north and baltic seas, most devastating epidemics in seals were also caused by cdv. to further study the pathogenesis of cdv infection in seals, it was the aim of the present study to investigate the mechanisms of cdv induced immunosuppression in seals by analyzing the gene transcription of d ...201425190509
auditory detection of ultrasonic coded transmitters by seals and sea lions.ultrasonic coded transmitters (ucts) are high-frequency acoustic tags that are often used to conduct survivorship studies of vulnerable fish species. recent observations of differential mortality in tag control studies suggest that fish instrumented with ucts may be selectively targeted by marine mammal predators, thereby skewing valuable survivorship data. in order to better understand the ability of pinnipeds to detect uct outputs, behavioral high-frequency hearing thresholds were obtained fro ...201425234996
surveillance for zoonotic and selected pathogens in harbor seals phoca vitulina from central california.the infection status of harbor seals phoca vitulina in central california, usa, was evaluated through broad surveillance for pathogens in stranded and wild-caught animals from 2001 to 2008, with most samples collected in 2007 and 2008. stranded animals from mendocino county to san luis obispo county were sampled at a rehabilitation facility: the marine mammal center (tmmc, n = 175); wild-caught animals were sampled at 2 locations: san francisco bay (sf, n = 78) and tomales bay (tb, n = 97), that ...201425266897
esophageal squamous cell carcinoma in six harbor seals (phoca vitulina spp.).six cases of esophageal squamous cell carcinoma were identified in six captive adult pacific (phoca vitulina richardsii; n = 2) and atlantic (phoca vitulina concolor; n = 4) harbor seals. these seals presented with intermittent dysphagia, regurgitation, inappetence, and abnormal posturing. common clinical pathology findings in these seals included azotemia, hyperproteinemia, hyperglobulinemia, and leukocytosis. gastrointestinal endoscopy commonly revealed an ulcerated mass near the gastroesophag ...201425314830
are vibrissae viable sensory structures for prey capture in northern elephant seals, mirounga angustirostris?little is known about the tactics northern elephant seals (nes) use to capture prey due to the difficulties in observing these animals underwater. nes forage on vertically migrating prey at depths >500 m during day and at night where light levels are negligible. although nes have increased visual sensitivity in deep water, vision is likely a limited sensory modality. still images of nes foraging show that the mystacial vibrissae are protracted before prey capture. as a representative phocid, har ...201525331439
molecular epidemiology of seal parvovirus, 1988-2014.a novel parvovirus was discovered recently in the brain of a harbor seal (phoca vitulina) with chronic meningo-encephalitis. phylogenetic analysis of this virus indicated that it belongs to the genus erythroparvovirus, to which also human parvovirus b19 belongs. in the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (sepv) infections was evaluated in both harbor and grey seals (halichoerus grypus) that lived in northwestern european coastal waters from ...201425390639
evaluation of viruses and their association with ocular lesions in pinnipeds in rehabilitation.to assess whether corneal lesions in stranded pinnipeds were associated with viral infections, and to identify the potential pathogen(s) associated with the lesions.201525400019
innervation patterns of sea otter (enhydra lutris) mystacial follicle-sinus complexes.sea otters (enhydra lutris) are the most recent group of mammals to return to the sea, and may exemplify divergent somatosensory tactile systems among mammals. therefore, we quantified the mystacial vibrissal array of sea otters and histologically processed follicle-sinus complexes (f - scs) to test the hypotheses that the number of myelinated axons per f - sc is greater than that found for terrestrial mammalian vibrissae and that their organization and microstructure converge with those of pinn ...201425400554
avian influenza a(h10n7) virus involvement in mass mortality of harbour seals (phoca vitulina) in sweden, march through october 2014.we provide the first scientific report of influenza a virus involvement in a mass mortality event among harbour seals (phoca vitulina) off the west coast of sweden. avian influenza a (h10n7) virus was detected in the lungs of two affected animals. this subtype has not been reported in seals to date, nor has influenza a-associated mortality been reported in seals in europe. circulation of avian influenza viruses in mammals may have implications for public health.201425425511
inflation and deflation pressure-volume loops in anesthetized pinnipeds confirms compliant chest and lungs.we examined structural properties of the marine mammal respiratory system, and tested scholander's hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia (pacific harbor seal, phoca vitulina; northern elephant seal, mirounga angustirostris; northern fur seal callorhinus ursinus; california sea lion, zalophus californianus; and steller sea lion, eumetopias jubatus). we found that the chest wall co ...201425426080
auditory sensitivity of seals and sea lions in complex listening scenarios.standard audiometric data, such as audiograms and critical ratios, are often used to inform marine mammal noise-exposure criteria. however, these measurements are obtained using simple, artificial stimuli-i.e., pure tones and flat-spectrum noise-while natural sounds typically have more complex structure. in this study, detection thresholds for complex signals were measured in (i) quiet and (ii) masked conditions for one california sea lion (zalophus californianus) and one harbor seal (phoca vitu ...201425480085
sensitivity of a harbor seal (phoca vitulina) to coherent visual motion in random dot displays.motion vision is one of the fundamental properties of the visual system and is involved in numerous tasks. previous work has shown that harbor seals are able to perceive visual motion. tying in with this experimental finding, we assessed the sensitivity of harbor seals to visual motion using random dot displays. in these random dot displays, either all or a percentage of the dots plotted in the display area move into one direction which is referred to as percent coherence. using random dot displ ...201425520911
identification of dna sequences that imply a novel gammaherpesvirus in seals.various herpesviruses have been discovered in marine mammals and are associated with a wide spectrum of disease. in the present study we describe the detection and phylogenetic analysis of a novel gammaherpesvirus, tentatively called phocine herpesvirus 7 (phhv-7), which was detected in samples collected during an outbreak of ulcerative gingivitis and glossitis from juvenile harbour seals (phoca vitulina) at the seal rehabilitation and research centre, the netherlands. the presence of this novel ...201525524165
phocine distemper virus: current knowledge and future directions.phocine distemper virus (pdv) was first recognized in 1988 following a massive epidemic in harbor and grey seals in north-western europe. since then, the epidemiology of infection in north atlantic and arctic pinnipeds has been investigated. in the western north atlantic endemic infection in harp and grey seals predates the european epidemic, with relatively small, localized mortality events occurring primarily in harbor seals. by contrast, pdv seems not to have become established in european ha ...201425533658
structural and functional analysis of surface proteins from an a(h3n8) influenza virus isolated from new england harbor seals.in late 2011, an a(h3n8) influenza virus infection resulted in the deaths of 162 new england harbor seals. virus sequence analysis and virus receptor binding studies highlighted potential markers responsible for mammalian adaptation and a mixed receptor binding preference (s. j. anthony, j. a. st leger, k. pugliares, h. s. ip, j. m. chan, z. w. carpenter, i. navarrete-macias, m. sanchez-leon, j. t. saliki, j. pedersen, w. karesh, p. daszak, r. rabadan, t. rowles, w. i. lipkin, mbio 3:e00166-0011 ...201525540377
development of a one-step duplex rt-qpcr for the quantification of phocine distemper virus.worldwide, stranded marine mammals and the network personnel who respond to marine mammal mortality have provided much of the information regarding marine morbillivirus infections. an assay to determine the amount of virus present in tissue samples would be useful to assist in routine surveying of animal health and for monitoring large-scale die-off events. false negatives from poor-quality samples prevent determination of the true extent of infection, while only small amounts of tissue samples ...201525647591
coccidioidomycosis and other systemic mycoses of marine mammals stranding along the central california, usa coast: 1998-2012.a wide range of systemic mycoses have been reported from captive and wild marine mammals from north america. examples include regionally endemic pathogens such as coccidioides and blastomyces spp., and novel pathogens like cryptococcus gattii, which appear may have been introduced to north america by humans. stranding and necropsy data were analyzed from three marine mammal stranding and response facilities on the central california coast to assess the prevalence, host demographics, and lesion d ...201525647598
unique fur and skin structure in harbour seals (phoca vitulina)--thermal insulation, drag reduction, or both?vertebrate surface structures, including mammalian skin and hair structures, have undergone various modifications during evolution in accordance with functional specializations. harbour seals rely on their vibrissal system for orientation and foraging. to maintain tactile sensitivity even at low temperatures, the vibrissal follicles are heated up intensely, which could cause severe heat loss to the environment. we analysed skin samples of different body parts of harbour seals, and expected to se ...201525652462
detection and effects of harmful algal toxins in scottish harbour seals and potential links to population decline.over the past 15 years or so, several scottish harbour seal (phoca vitulina) populations have declined in abundance and several factors have been considered as possible causes, including toxins from harmful algae. here we explore whether a link could be established between two groups of toxins, domoic acid (da) and saxitoxins (stxs), and the decline in the harbour seal populations in scotland. we document the first evidence that harbour seals are exposed to both da and stxs from consuming contam ...201525666120
harbour seal (phoca vitulina) pmn and monocytes release extracellular traps to capture the apicomplexan parasite toxoplasma gondii.extracellular traps (ets) are composed of nuclear dna as backbone adorned with histones, cytoplasmic antimicrobial peptides/proteins which are released from a range of vertebrate and invertebrate host immune cells in response to several invading pathogens. until now this ancient novel innate defence mechanism has not been demonstrated in any marine mammal. interactions of harbour seal (phoca vitulina)-pmn and -monocytes with viable tachyzoites of toxoplasma gondii were investigated in this respe ...201525681075
influenza a(h10n7) virus in dead harbor seals, denmark.since april 2014, an outbreak of influenza in harbor seals has been ongoing in northern europe. in denmark during june-august, 152 harbor seals on the island of anholt were found dead from severe pneumonia. we detected influenza a(h10n7) virus in 2 of 4 seals examined.201525811098
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