Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| a recombinant antigen-based enzyme-linked immunosorbent assay (elisa) for lungworm detection in seals. | pinnipeds are frequently infected by the lungworms otostrongylus circumlitus and parafilaroides gymnurus (metastrongyloidea). infections are frequently associated with secondary bacterial bronchopneumonia and are often lethal. to date, a reliable lungworm diagnosis in individual seals is only possible during necropsy as examination of faeces collected from resting places does not allow assignment to individuals. therefore, a diagnostic tool for lungworm detection in living seals is desirable for ... | 2015 | 26329933 |
| surgical treatment of osteoarthritis in harbor seals (phoca vitulina). | in 2012, 543 harbor seals (phoca vitulina) and 124 grey seals (halichoerus grypus) were admitted to the seal rehabilitation and research centre in pieterburen, the netherlands. in 19 seals (3%), signs of infection in a hind flipper were observed. initial treatment consisting of antibiotics and anti-inflammatory drugs resolved the symptoms in 15 animals. in four harbor seals, estimated to be 3 to 4 mo old, a necrotizing infection developed that resulted in osteoarthritis of the tarsus or tibiotar ... | 2015 | 26352960 |
| can a gray seal (halichoerus grypus) generalize call classes? | past researchers have found that gray seals (halichoerus grypus) are capable of classifying vocal signals by call type using a trained set, but were unable to generalize to novel exemplars (shapiro, slater, & janik, 2004). given the importance of auditory categorization in communication, it would be surprising if the animals were unable to generalize acoustically similar calls into classes. here, we trained a juvenile gray seal to discriminate novel calls into 2 classes, "growls" and "moans," by ... | 2015 | 26460856 |
| herpesviruses including novel gammaherpesviruses are widespread among phocid seal species in canada. | little is known about herpesviruses in canadian pinnipeds. we measured prevalence of antibodies to herpesviruses in the sera from canadian phocid seals by an indirect enzyme-linked immunosorbent assay. wild harbor seals (phoca vitulina) and captive harbor seals were positive for antibodies to phocid herpesvirus 1 (phohv-1) at prevalences of 91% and 100%, respectively. sera from wild hooded seals (cystophora cristata), harp seals (pagophilus groenlandica), and grey seals (halichoerus grypus) were ... | 2016 | 26555112 |
| impacts of underwater noise on marine vertebrates: project introduction and first results. | the project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the north and baltic seas. in distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise from pile driving and stress reactions caused by anthropogenic noise is investigated. animals are equipped with dtags capable of recording the actual surrounding noise field of free-swimming harbor porpo ... | 2016 | 26611013 |
| seroprevalence of antibodies against seal influenza a(h10n7) virus in harbor seals and gray seals from the netherlands. | in the spring and summer 2014, an outbreak of seal influenza a(h10n7) virus infection occurred among harbor seals (phoca vitulina) off the coasts of sweden and denmark. this virus subsequently spread to harbor seals off the coasts of germany and the netherlands. while thousands of seals were reported dead in sweden, denmark and germany, only a limited number of seals were found dead in the netherlands. to determine the extent of exposure of seals in the netherlands to influenza a/h10n7 virus, we ... | 2015 | 26658347 |
| sediment contaminant surveillance in milford haven waterway. | sediment contaminants were monitored in milford haven waterway (mhw) since 1978 (hydrocarbons) and 1982 (metals), with the aim of providing surveillance of environmental quality in one of the uk's busiest oil and gas ports. this aim is particularly important during and after large-scale investment in liquefied natural gas (lng) facilities. however, the methods inevitably have changed over the years, compounding the difficulties of coordinating sampling and analytical programmes. after a review b ... | 2016 | 26676410 |
| maternal oxytocin is linked to close mother-infant proximity in grey seals (halichoerus grypus). | maternal behaviour is a crucial component of reproduction in all mammals; however the quality of care that mothers give to infants can vary greatly. it is vital to document variation in maternal behaviour caused by the physiological processes controlling its expression. this underlying physiology should be conserved throughout reproductive events and should be replicated across all individuals of a species; therefore, any correlates to maternal care quality may be present across many individuals ... | 2015 | 26698856 |
| phenotypic, genotypic, and antimicrobial characteristics of streptococcus halichoeri isolates from humans, proposal to rename streptococcus halichoeri as streptococcus halichoeri subsp. halichoeri, and description of streptococcus halichoeri subsp. hominis subsp. nov., a bacterium associated with human clinical infections. | phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of streptococcus halichoeri isolated from a seal are presented. sequencing of the 16s rrna, rpob, soda, and recn genes; comparative whole-genome analysis; conventional biochemical and rapid id 32 strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of s. halichoeri, and t ... | 2016 | 26763962 |
| salmonella infection in grey seals (halichoerus grypus), a marine mammal sentinel species: pathogenicity and molecular typing of salmonella strains compared with human and livestock isolates. | microbial pollution of the marine environment through land-sea transfer of human and livestock pathogens is of concern. salmonella was isolated from rectal swabs of free-ranging and stranded grey seal pups (21.1%; 37/175) and compared with strains from the same serovars isolated from human clinical cases, livestock, wild mammals and birds in scotland, uk to characterize possible transmission routes using pulsed-field gel electrophoresis and multi-locus variable number of tandem repeat analyses. ... | 2016 | 26768299 |
| mercury in marine fish, mammals, seabirds, and human hair in the coastal zone of the southern baltic. | mercury (hg), aside from having high toxicity, is characterized by its ability to biomagnify in the marine trophic chain. this is an important problem especially in estuaries, or in the coastal zone, particularly near the mouths of large rivers. this study was conducted in the years 2001-2011, in the coastal zone of the baltic sea near to the mouth of the river vistula, which is the second biggest river discharging into the baltic. mercury concentration was measured in the tissues and organs of ... | 2017 | 26806985 |
| meals on wheels? a decade of megafaunal visual and acoustic observations from offshore oil & gas rigs and platforms in the north and irish seas. | a decade of visual and acoustic detections of marine megafauna around offshore oil & gas (o&g) installations in the north and irish seas are presented. marine megafauna activity was monitored visually and acoustically by joint nature conservation committee (jncc) qualified and experienced marine mammal observers (mmo) and passive acoustic monitoring (pam) operators respectively, with real-time towed pam in combination with industry standard software, pamguard. monitoring was performed during rou ... | 2016 | 27078153 |
| conjunctival flora of healthy and diseased eyes of grey seals (halichoerus grypus): implications for treatment. | ocular pathology is relatively common in stranded seals admitted to wildlife rehabilitation hospitals. some have pre-existing problems, while others develop eye problems in captivity, and in particular ulcerative keratitis, due to factors such as large prominent eyes, suboptimal water quality, trauma and infighting. despite treatment, corneal ulcerations can rapidly progress to 'melting' ulcers with subsequent rupture of the globe. in this case series, 32 grey seals (halichoerus grypus) had conj ... | 2016 | 27188623 |
| corkscrew seals: grey seal (halichoerus grypus) infanticide and cannibalism may indicate the cause of spiral lacerations in seals. | large numbers of dead seals with characteristic spiral lesions have been washing ashore around the north atlantic over the past two decades. interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. however, new evidence points towards a more likely candidate: grey seal predation. an adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the isle of may, scotland. a furth ... | 2016 | 27254025 |
| host size-dependent anisakid infection in baltic cod gadus morhua associated with differential food preferences. | a significant increase in the infection level of baltic cod gadus morhua with the anisakid nematode larvae contracaecum osculatum and pseudoterranova decipiens has been recorded during recent years due to the expanding local population of grey seals halichoerus grypus, which act as final hosts for these parasites. here, we report from an investigation of 368 cod (total length [tl] 6-49 cm; caught in ices subdivision 25) that the infection level of juvenile cod (tl 6-30 cm) with larvae of c. oscu ... | 2016 | 27304871 |
| prevalence of influenza a virus in live-captured north atlantic gray seals: a possible wild reservoir. | influenza a virus (iav) has been associated with multiple unusual mortality events (umes) in north atlantic pinnipeds, frequently attributed to spillover of virus from wild-bird reservoirs. to determine if endemic infection persists outside of umes, we undertook a multiyear investigation of iav in healthy, live-captured northwest atlantic gray seals (halichoerus grypus). from 2013 to 2015, we sampled 345 pups and 57 adults from cape cod, ma, usa and nova scotia, canada consistently detecting iav ... | 2016 | 27485496 |
| development of an animal-borne blood sample collection device and its deployment for the determination of cardiovascular and stress hormones in phocid seals. | an animal-borne blood sampler with data-logging functions was developed for phocid seals, which collected two blood samples for the comparison of endocrinological/biochemical parameters under two different conditions. the sampler can be triggered by preset hydrostatic pressure, acceleration (descending or ascending), temperature, and time, and also manually by light. the sampling was reliable with 39/50 (78%) successful attempts to collect blood samples. contamination of fluids in the tubing to ... | 2016 | 27581813 |
| shift of grey seal subspecies boundaries in response to climate, culling and conservation. | identifying the processes that drive changes in the abundance and distribution of natural populations is a central theme in ecology and evolution. many species of marine mammals have experienced dramatic changes in abundance and distribution due to climatic fluctuations and anthropogenic impacts. however, thanks to conservation efforts, some of these species have shown remarkable population recovery and are now recolonizing their former ranges. here, we use zooarchaeological, demographic and gen ... | 2016 | 27616353 |
| shipping noise in a dynamic sea: a case study of grey seals in the celtic sea. | shipping noise is a threat to marine wildlife. grey seals are benthic foragers, and thus experience acoustic noise throughout the water column, which makes them a good model species for a case study of the potential impacts of shipping noise. we used ship track data from the celtic sea, seal track data and a coupled ocean-acoustic modelling system to assess the noise exposure of grey seals along their tracks. it was found that the animals experience step changes in sound levels up to ~20db at a ... | 2017 | 27677390 |
| spatial overlap of grey seals and fisheries in irish waters, some new insights using telemetry technology and vms. | seals and humans often target the same food resource, leading to competition. this is of mounting concern with fish stocks in global decline. grey seals were tracked from southeast ireland, an area of mixed demersal and pelagic fisheries, and overlap with fisheries on the celtic shelf and irish sea was assessed. overall, there was low overlap between the tagged seals and fisheries. however, when we separate active (e.g. trawls) and passive gear (e.g. nets, lines) fisheries, a different picture e ... | 2017 | 27682443 |
| biomonitoring of selected persistent organic pollutants (pcdd/fs, pcbs and pbdes) in finnish and russian terrestrial and aquatic animal species. | the finnish and russian animal species (semi-domesticated reindeer, finnish wild moose, baltic grey seal and baltic herring) samples were biomonitored in terrestrial and aquatic environments for polychlorinated dibenzo-p-dioxins and dibenzofurans (pcdd/fs), polychlorinated biphenyls (pcbs) and polybrominated diphenylethers (pbdes). | 2016 | 27752440 |
| emergence of the zoonotic biliary trematode pseudamphistomum truncatum in grey seals (halichoerus grypus) in the baltic sea. | the biliary trematode pseudamphistomum truncatum parasitizes a wide range of fish-eating mammals, including humans. here we report the emergence of this parasite in grey seals (halichoerus grypus) in the baltic sea. one hundred eighty-three of 1 554 grey seals (11.9%) examined from 2002-2013 had detectable hepatobiliary trematode infection. parasite identification was confirmed as p. truncatum by sequencing the its2 region of a pool of five to 10 trematodes from each of ten seals collected off t ... | 2016 | 27755567 |
| density-dependent resource selection by a terrestrial herbivore in response to sea-to-land nutrient transfer by seals. | sea-to-land nutrient transfers can connect marine food webs to those on land, creating a dependence on marine webs by opportunistic species. we show how nitrogen, imported by gray seals, halichoerus grypus, and traced through stable isotope (δ(15) n) measurements in marram grass, ammophila breviligulata, significantly alters foraging behavior of a free-roaming megaherbivore (feral horses, equus ferus caballus) on sable island, canada. values of δ(15) n correlated with protein content of marram a ... | 2016 | 27859192 |
| factors influencing and consequences of breeding dispersal and habitat choice in female grey seals (halichoerus grypus) on sable island, nova scotia. | selection of breeding location can influence reproductive success and fitness. breeding dispersal links habitat use and reproduction. this study investigated factors affecting breeding dispersal and its reproductive consequences in grey seals (halichoerus grypus) on sable island, nova scotia. breeding dispersal distance was determined in 692 individually marked, known-age female grey seals observed from 2004 to 2014. we used generalized linear mixed-effects models to test hypotheses concerning e ... | 2017 | 27864645 |
| antidog igg secondary antibody successfully detects igg in a variety of aquatic mammals. | serological tests play an important role in the detection of wildlife diseases. however, while there are many commercial assays and reagents available for domestic species, there is a need to develop efficient serological assays for wildlife. in recent years, marine mammals have represented a wildlife group with emerging infectious diseases, such as influenza, brucellosis, and leptospirosis. however, with the exception of disease-agent-specific assays or functional assays, few reports describe t ... | 2016 | 28080908 |
| contracaecum osculatum and other anisakid nematodes in grey seals and cod in the baltic sea: molecular and ecological links. | populations of grey seals (halichoerus grypus), sprats (sprattus sprattus) and cod (gadus morhua) in the baltic sea are relatively stationary. the present work, applying classical and molecular helminthological techniques, documents that seals and cod also share a common parasite, the anisakid nematode contracaecum osculatum, which uses seals as the final host and fish as transport hosts. sequencing mitochondrial genes (cox1 and cox2) in adult worms from seals and third-stage larvae from livers ... | 2017 | 28124629 |
| estimating partial regulation in spatiotemporal models of community dynamics. | niche-based approaches to community analysis often involve estimating a matrix of pairwise interactions among species (the "community matrix"), but this task becomes infeasible using observational data as the number of modeled species increases. as an alternative, neutral theories achieve parsimony by assuming that species within a trophic level are exchangeable, but generally cannot incorporate stabilizing interactions even when they are evident in field data. finally, both regulated (niche) an ... | 2017 | 28144946 |
| dirofilaria immitis in pinnipeds and a new host record. | dirofilaria immitis is a mosquito-borne pathogen that is spreading worldwide, and the associated infection (i.e. dirofilariosis) is becoming a threat to animals and humans living in endemic areas. little is known about the occurrence and risk of infection of d. immitis in pinnipeds. here we report dirofilariosis by d. immitis in several pinniped species kept in captivity in portugal. | 2017 | 28288690 |
| automated detection and enumeration of marine wildlife using unmanned aircraft systems (uas) and thermal imagery. | estimating animal populations is critical for wildlife management. aerial surveys are used for generating population estimates, but can be hampered by cost, logistical complexity, and human risk. additionally, human counts of organisms in aerial imagery can be tedious and subjective. automated approaches show promise, but can be constrained by long setup times and difficulty discriminating animals in aggregations. we combine unmanned aircraft systems (uas), thermal imagery and computer vision to ... | 2017 | 28338047 |
| a simulation approach to assessing environmental risk of sound exposure to marine mammals. | intense underwater sounds caused by military sonar, seismic surveys, and pile driving can harm acoustically sensitive marine mammals. many jurisdictions require such activities to undergo marine mammal impact assessments to guide mitigation. however, the ability to assess impacts in a rigorous, quantitative way is hindered by large knowledge gaps concerning hearing ability, sensitivity, and behavioral responses to noise exposure. we describe a simulation-based framework, called safesimm (statist ... | 2017 | 28405276 |
| a hidden markov movement model for rapidly identifying behavioral states from animal tracks. | electronic telemetry is frequently used to document animal movement through time. methods that can identify underlying behaviors driving specific movement patterns can help us understand how and why animals use available space, thereby aiding conservation and management efforts. for aquatic animal tracking data with significant measurement error, a bayesian state-space model called the first-difference correlated random walk with switching (dcrws) has often been used for this purpose. however, f ... | 2017 | 28405277 |
| obtaining accurate glucose measurements from wild animals under field conditions: comparing a hand held glucometer with a standard laboratory technique in grey seals. | glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. however, seals show unusual glucose regulation: circulati ... | 2017 | 28413683 |
| human hair, baltic grey seal (halichoerus grypus) fur and herring gull (larus argentatus) feathers as accumulators of bisphenol a and alkylphenols. | the purpose of the study was to determine the concentration of bisphenol a (bpa), 4-tert-octylphenol (op), and 4-nonylphenol (np), in human hair, the fur of baltic grey seals and the feathers of herring gulls. hair was collected from 42 volunteers, while grey seal fur (n = 17) came from the seal centre in hel (marine station of institute of oceanography, university of gdansk) and gull covert feathers (n = 26) were collected from dead herring gulls along the southern baltic coast. assays of pheno ... | 2017 | 28451711 |
| positive social behaviours are induced and retained after oxytocin manipulations mimicking endogenous concentrations in a wild mammal. | the neuropeptide hormone oxytocin modulates numerous social and parental behaviours across a wide range of species, including humans. we conducted manipulation experiments on wild grey seals (halichoerus grypus) to determine whether oxytocin increases proximity-seeking behaviour, which has previously been correlated with endogenous oxytocin concentrations in wild seal populations. pairs of seals that had never met previously were given intravenous injections of 0.41 µg kg(-1) oxytocin or saline ... | 2017 | 28539519 |
| recovery of the first full-length genome sequence of a parapoxvirus directly from a clinical sample. | we recovered the first full-length poxvirus genome, including the terminal hairpin region, directly from complex clinical material using a combination of second generation short read and third generation nanopore sequencing technologies. the complete viral genome sequence was directly recovered from a skin lesion of a grey seal thereby preventing sequence changes due to in vitro passaging of the virus. subsequent analysis of the proteins encoded by this virus identified genes specific for skin a ... | 2017 | 28623312 |
| first longitudinal study of seal-feeding killer whales (orcinus orca) in norwegian coastal waters. | killer whales (orcinus orca) have been documented preying on either fish or marine mammals in several regions, suggesting that this odontocete species has the ability to specialize on different types of prey. off norway, killer whales have been shown to rely on the atlantic herring (clupea harengus) as a main prey resource. infrequent observations have revealed seals as an additional component of their diet, yet the extent of predation on marine mammals has remained largely unknown. here, we pre ... | 2017 | 28666015 |
| nuclear reprocessing-related radiocarbon ((14)c) uptake into uk marine mammals. | to evaluate the transfer of sellafield-derived radiocarbon ((14)c) to top predators in the uk marine environment, (14)c activities were examined in stranded marine mammals. all samples of harbour porpoise (phocoena phocoena) obtained from the irish sea showed (14)c enrichment above background. mammal samples obtained from the west of scotland, including harbour porpoise, grey seals (halichoerus grypus) and harbour seals (phoca vitulina) showed (14)c enrichment but to a lesser extent. this study ... | 2017 | 28693808 |
| isolation of brucella pinnipedialis from grey seals (halichoerus grypus) in the baltic sea. | brucella infection in seals was reported for the first time in 1994 around the coast of scotland. since then, marine mammal brucella infections were found to be widely distributed in the northern hemisphere. two brucella species affect marine mammals: brucella pinnipedialis in pinnipeds and brucella ceti in cetaceans. we examined the livers of baltic grey seals (halichoerus grypus) from the finnish coast (n=122) hunted, found dead, or killed as by-catch in fishing gear in 2013-15 as part of popu ... | 2017 | 28715291 |
| marine debris in harbour porpoises and seals from german waters. | records of marine debris in and attached to stranded harbour porpoises (phocoena phocoena), harbour seals (phoca vitulina) and grey seals (halichoerus grypus) were studied comprising information on 6587 carcasses collected along the german coast between 1990 and 2014, the decomposition state allowed for necropsy in 1622 cases. marine debris items were recorded in 31 carcasses including 14 entanglements (5 harbour porpoises, 6 harbour seals, 3 grey seals) and 17 cases of ingestion (4 harbour porp ... | 2017 | 28735731 |
| extrusion of contracaecum osculatum nematode larvae from the liver of cod (gadus morhua). | baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of contracaecum osculatum. the infections are associated with an increasing population of grey seals which are final hosts for the parasite. heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. we investigated the attachment of the worm larvae in liver tissue by use of histochemical technique ... | 2017 | 28795224 |
| using blubber explants to investigate adipose function in grey seals: glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone. | adipose tissue is fundamental to energy balance, which underpins fitness and survival. knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. we investigated glucose removal, lactate, glycerol and nefa accumula ... | 2017 | 28798409 |
| transfer of mercury and phenol derivatives across the placenta of baltic grey seals (halichoerus grypus grypus). | the placenta is an intermediary organ between the female and the developing foetus. some chemical substances, including the most harmful ones, exhibit the ability to accumulate in or penetrate through the placenta. the aim of the study was to determine the role of the placenta of the baltic grey seal (halichoerus grypus grypus) in the transfer of endocrine disrupting compounds (edcs) - (bisphenol a, 4-tert- octylphenol, 4- nonylphenol), as well as total and organic mercury. 30 placentas were col ... | 2017 | 28898953 |
| impact of ocean warming on sustainable fisheries management informs the ecosystem approach to fisheries. | an integrated ecosystem model including fishing and the impact of rising temperatures, relative to species' thermal ranges, was used to assess the cumulative effect of future climate change and sustainable levels of fishing pressure on selected target species. historically, important stocks of cod and whiting showed declining trends caused by high fisheries exploitation and strong top-down control by their main predators (grey seals and saithe). in a no-change climate scenario these stocks recov ... | 2017 | 29044134 |
| prevalence of presenting conditions in grey seal pups (halichoerus grypus) admitted for rehabilitation. | a retrospective survey was performed on the presenting conditions of 205 live grey seal pups (halichoerus grypus) admitted to the cornish seal sanctuary in gweek, united kingdom between may 2005 and march 2011. the purpose of the survey was to examine the prevalence of various presenting signs at the sanctuary. the presenting signs were classified into nine non-mutually exclusive categories: ocular disorders, nasal disorders, oral disorders, respiratory disorders, orthopaedic disorders, puncture ... | 2015 | 29061924 |
| arcanobacterium phocae infection in mink (neovison vison), seals (phoca vitulina, halichoerus grypus) and otters (lutra lutra). | infectious skin disorders are not uncommon in mink. such disorders are important as they have a negative impact on animal health and welfare as well as on the quality and value of the fur. this study presents the isolation of arcanobacterium phocae from mink with severe skin lesions and other pathological conditions, and from wild seals and otters. | 2017 | 29073927 |
| intrinsic and extrinsic factors drive ontogeny of early-life at-sea behaviour in a marine top predator. | young animals must learn to forage effectively to survive the transition from parental provisioning to independent feeding. rapid development of successful foraging strategies is particularly important for capital breeders that do not receive parental guidance after weaning. the intrinsic and extrinsic drivers of variation in ontogeny of foraging are poorly understood for many species. grey seals (halichoerus grypus) are typical capital breeders; pups are abandoned on the natal site after a brie ... | 2017 | 29138511 |
| rapid changes in atlantic grey seal milk from birth to weaning - immune factors and indicators of metabolic strain. | true seals have the shortest lactation periods of any group of placental mammal. most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly wean. milk was collected from atlantic grey seals (halichoerus grypus) periodically from birth until near weaning. milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to ... | 2017 | 29170469 |
| bayesian joint models with inla exploring marine mobile predator-prey and competitor species habitat overlap. | understanding spatial physical habitat selection driven by competition and/or predator-prey interactions of mobile marine species is a fundamental goal of spatial ecology. however, spatial counts or density data for highly mobile animals often (1) include excess zeros, (2) have spatial correlation, and (3) have highly nonlinear relationships with physical habitat variables, which results in the need for complex joint spatial models. in this paper, we test the use of bayesian hierarchical hurdle ... | 2017 | 29242741 |
| prevalence and molecular characterisation of acanthocephala in pinnipedia of the north and baltic seas. | harbour seals (phoca vitulina) and grey seals (halichoerus grypus) are final hosts of acanthocephalans in the german north and baltic seas. parasitic infections in seals can cause pathological changes, which may result in deteriorated health of the host. common gastrointestinal parasites of harbour and grey seals are acanthocephalans and a number of 275 of 2460 (11.2%) investigated seals from 1996 to 2013 were infected with corynosoma spp. (acanthocephala, polymorphidae). the prevalence showed a ... | 2018 | 29387535 |
| evaluating the use of stable isotope analysis to infer the feeding ecology of a growing us gray seal (halichoerus grypus) population. | gray seals (halichoerus grypus) have been rapidly recolonizing the northeast us coast, eliciting concern from the fishing industry. however, the ecological effect of this recovery is still unknown and as such, research is needed to better understand how the diet composition of gray seals in us waters will contribute to the ecological impact. while previous research on seal diets has focused on the analysis of hard prey remains, stable isotope analysis presents an alternative method that can be u ... | 2018 | 29466372 |
| investigating microplastic trophic transfer in marine top predators. | microplastics are highly bioavailable to marine organisms, either through direct ingestion, or indirectly by trophic transfer from contaminated prey. the latter has been observed for low-trophic level organisms in laboratory conditions, yet empirical evidence in high trophic-level taxa is lacking. in natura studies face difficulties when dealing with contamination and differentiating between directly and indirectly ingested microplastics. the ethical constraints of subjecting large organisms, su ... | 2018 | 29477242 |
| bio accumulation of radioactive caesium in marine mammals in the baltic sea - reconstruction of a historical time series. | radionuclides from the chernobyl accident in 1986 still circulate in the baltic marine ecosystem and activity levels in water, sediments and fish species such as herring and perch are monitored annually. however, the activity levels of radionuclides in marine mammals have only been sporadically reported. tissue samples from a museum collection were analysed in two species of seals, and the trends over time in activity level of radioactive caesium (cs-137) after the chernobyl accident were recons ... | 2018 | 29518725 |
| assessing the disturbance potential of small unoccupied aircraft systems (uas) on gray seals (halichoerus grypus) at breeding colonies in nova scotia, canada. | the use of small unoccupied aircraft systems (uas) for ecological studies and wildlife population assessments is increasing. these methods can provide significant benefits in terms of costs and reductions in human risk, but little is known if uas-based approaches cause disturbance of animals during operations. to address this knowledge gap, we conducted a series of uas flights at gray seal breeding colonies on hay and saddle islands in nova scotia, canada. using a small fixed-wing uas, we assess ... | 2018 | 29576950 |
| google haul out: earth observation imagery and digital aerial surveys in coastal wildlife management and abundance estimation. | as the sampling frequency and resolution of earth observation imagery increase, there are growing opportunities for novel applications in population monitoring. new methods are required to apply established analytical approaches to data collected from new observation platforms (e.g., satellites and unmanned aerial vehicles). here, we present a method that estimates regional seasonal abundances for an understudied and growing population of gray seals (halichoerus grypus) in southeastern massachus ... | 2017 | 29599542 |
| brucella pinnipedialis in grey seals ( halichoerus grypus) and harbor seals ( phoca vitulina) in the netherlands. | brucellosis is a zoonotic disease with terrestrial or marine wildlife animals as potential reservoirs for the disease in livestock and human populations. the primary aim of this study was to assess the presence of brucella pinnipedialis in marine mammals living along the dutch coast and to observe a possible correlation between the presence of b. pinnipedialis and accompanying pathology found in infected animals. the overall prevalence of brucella spp. antibodies in sera from healthy wild grey s ... | 2018 | 29697310 |
| accumulation of pbdes in stranded harp (pagophilus groenlandicus) and hooded seals (cystophora cristata) from the northeastern united states. | polybrominated diphenyl ethers (pbdes) are highly lipophilic components of brominated flame retardants that are environmentally persistent and bioaccumulate. pbdes are taken up from the gastrointestinal tract and accumulate mainly in fat depots and liver tissues. seal species inhabiting arctic and sub-arctic regions can have upwards of 30% of their body mass composed of blubber. when those blubber stores are mobilized for energy, stored toxicants are also released into circulation. most studies ... | 2018 | 29706368 |
| heavy metal content in liver and kidneys of grey seals (halichoerus grypus) in various life stages correlated with metallothionein levels: some metal-binding characteristics of this protein. | liver and kidneys from grey seals (halichoerus grypus) in their natural habitats in norwegian waters contain high levels of cd and hg as well as metallothionein (mt). the data show significant placental transfer of heavy metals in seals. the mt concentrations were higher in fetus liver and kidneys than in the liver and kidneys of juveniles and adults. a significantly higher proportion of the total cd and cu, as compared to zn and hg, in fetal liver was associated with mt. only low amounts of met ... | 1999 | 29857630 |
| a novel quantitative real-time pcr diagnostic assay for seal heartworm (acanthocheilonema spirocauda) provides evidence for possible infection in the grey seal (halichoerus grypus). | the distinct evolutionary pressures faced by pinnipeds have likely resulted in strong coevolutionary ties to their parasites (leidenberger et al., 2007). this study focuses on the phocid seal filarial heartworm species acanthocheilonema spirocauda. a. spirocauda is known to infect a variety of phocid seals, but does not appear to be restricted to a single host species (measures et al., 1997; leidenberger et al., 2007; lehnert et al., 2015). however, to date, seal heartworm has never been reporte ... | 2018 | 29988808 |
| genomic signatures of population bottleneck and recovery in northwest atlantic pinnipeds. | population increases over the past several decades provide natural settings in which to study the evolutionary processes that occur during bottleneck, growth, and spatial expansion. we used parallel natural experiments of historical decline and subsequent recovery in two sympatric pinniped species in the northwest atlantic, the gray seal (halichoerus grypus atlantica) and harbor seal (phoca vitulina vitulina), to study the impact of recent demographic change in genomic diversity. using restricti ... | 2018 | 30038760 |
| maternal transfer of phenol derivatives in the baltic grey seal halichoerus grypus grypus. | studies of circulating levels in difference sex and age classes, and maternal transfer of bisphenol a, 4-tert-octylphenol and 4- nonylphenol in the baltic grey seal were performed from 2014-2017. blood was collected from long-term captive adult males, pregnant females and pups. milk was collected from nursing females. the aim of this study was not only to determine the concentrations of phenol derivatives, i.e. bisphenol a (bpa), 4-tert-octylphenol (op) and 4-nonylphenol (np), but also to try to ... | 2018 | 30072224 |
| new approach to stress research in phocids-potential of dehydroepiandrosterone and cortisol/dehydroepiandrosterone ratio as markers for stress in harbor seals ( phoca vitulina) and gray seals ( halichoerus grypus). | cortisol is known to reflect the level of the stress response. however, measuring the cortisol concentration only once fails to provide sufficient information about the duration of the stress exposure. moreover, handling is an acute stressor and increases cortisol secretion especially in wildlife species. yet, in phocids reliable indicators are missing that reflect potential chronic effects of stress. the adrenal-derived steroid hormone dehydroepiandrosterone (dhea) has been described as biomark ... | 2018 | 30212331 |
| analytical methods for determination of bisphenol a, 4-tert-octylphenol and 4-nonylphenol in herrings and physiological fluids of the grey seal. | •the aim of this work was to develop the methods of determination for phenol derivatives: bisphenol a (bpa), 4-tert-octylphenol (op) and 4-nonylphenol (np), in the whole body of herring clupea harengus and in physiological fluids of the baltic grey seal halichoerus grypus grypus (blood and milk).•methods were based on liquid chromatography coupled with a fluorescence detector (hplc-fl).•these methods were satisfactorily validated, each showing good recovery (>80%) and precision (rsd < 15%). rega ... | 2018 | 30294560 |
| persistent organic pollutant burden, experimental pop exposure, and tissue properties affect metabolic profiles of blubber from gray seal pups. | persistent organic pollutants (pops) are toxic, ubiquitous, resist breakdown, bioaccumulate in living tissue, and biomagnify in food webs. pops can also alter energy balance in humans and wildlife. marine mammals experience high pop concentrations, but consequences for their tissue metabolic characteristics are unknown. we used blubber explants from wild, gray seal ( halichoerus grypus) pups to examine impacts of intrinsic tissue pop burden and acute experimental pop exposure on adipose metaboli ... | 2018 | 30339760 |
| prevalence of alopecia in gray seals halichoerus grypus atlantica in massachusetts, usa, 2004-2013. | there has been an increase in the presence of alopecia among gray seals halichoerus grypus atlantica in massachusetts, usa. to understand the prevalence and describe the presentation of this condition, data records and photographs of 10070 gray seals from 2004-2013 were reviewed; there were sufficient data to confidently assess the presence or absence of alopecia in 2134 seals. mild hair loss presented in multifocal patches with minimal to no skin lesions or erythema. in severe cases, alopecia w ... | 2018 | 30459289 |
| the necessity of a holistic approach when managing marine mammal-fisheries interactions: environment and fisheries impact are stronger than seal predation. | seal populations are recovering in many regions around the world and, consequently, they are increasingly interacting with fisheries. we used an ecopath with ecosim model for the offshore central baltic sea to investigate the interactions between the changes in fish stocks and grey seal (halichoerus grypus) population under different fishing and environmental scenarios for the twenty-first century. the assumed climate, eutrophication and cod (gadus morhua) fisheries scenarios modified seal preda ... | 2019 | 30536186 |
| cryptosporidium species and giardia species prevalence in marine mammal species present in the german north and baltic seas. | marine mammals are known to harbor cryptosporidium spp. and giardia spp., especially species or genotypes commonly associated with humans. in animals of the north and baltic seas, this information is missing. in this study, fecal samples ( n = 97) from harbor porpoises ( phocoena phocoena), harbor seals ( phoca vitulina), and grey seals ( phocoena phocoena) present in german waters were examined via microscopic examination (by using a modified ziehl-neelsen technique [mzn]) to estimate the preva ... | 2018 | 30592910 |
| spatial variation in a top marine predator's diet at two regionally distinct sites. | in ecological studies it is often assumed that predator foraging strategies and resource use are geographically and seasonally homogeneous, resulting in relatively static trophic relationships. however, certain centrally placed foragers (e.g. seals) often have terrestrial sites for breeding, resting, and moulting that are geographically distinct, and associated with different habitat types. therefore, accurate estimations of predator diet at relevant spatial and temporal scales are key to unders ... | 2019 | 30601852 |
| complementary methods assessing short and long-term prey of a marine top predator ‒ application to the grey seal-fishery conflict in the baltic sea. | the growing grey seal (halichoerus grypus) population in the baltic sea has created conflicts with local fisheries, comparable to similar emerging problems worldwide. adequate information on the foraging habits is a requirement for responsible management of the seal population. we investigated the applicability of available dietary assessment methods by comparing morphological analysis and dna metabarcoding of gut contents (short-term diet; n = 129/125 seals, respectively), and tissue chemical m ... | 2019 | 30601857 |
| sensitivity of multispecies maximum sustainable yields to trends in the top (marine mammals) and bottom (primary production) compartments of the southern north sea food-web. | in marine ecosystems, maximum sustainable yield considerations are affected by any substantial changes that occur in the top and bottom compartments of the food-web. this study explores how the southern north sea's fisheries may need to adjust their fishing efforts to maintain optimum yields of sole, plaice, cod and brown shrimps under increased marine mammal populations and a reduced primary productivity. we constructed plausible scenarios of ongoing food-web changes using the results of bayesi ... | 2019 | 30689649 |
| long-term sound and movement recording tags to study natural behavior and reaction to ship noise of seals. | the impact of anthropogenic noise on marine fauna is of increasing conservation concern with vessel noise being one of the major contributors. animals that rely on shallow coastal habitats may be especially vulnerable to this form of pollution.very limited information is available on how much noise from ship traffic individual animals experience, and how they may react to it due to a lack of suitable methods. to address this, we developed long-duration audio and 3d-movement tags (dtags) and depl ... | 2019 | 30891202 |
| classifying grey seal behaviour in relation to environmental variability and commercial fishing activity - a multivariate hidden markov model. | classifying movement behaviour of marine predators in relation to anthropogenic activity and environmental conditions is important to guide marine conservation. we studied the relationship between grey seal (halichoerus grypus) behaviour and environmental variability in the southwestern baltic sea where seal-fishery conflicts are increasing. we used multiple environmental covariates and proximity to active fishing nets within a multivariate hidden markov model (hmm) to quantify changes in moveme ... | 2019 | 30948786 |
| a review of the sealworm problem: biology, implications and solutions. | the life cycle and geographic distribution of the sealworm ( phocanema decipiens ) are reviewed. also discussed is the temperature tolerance of the third stage larva as well as its public health implications. it is concluded that there ought to be no public health hazards associated with the sealworm as long as people continue to process seafood properly. correlation between the increase in the grey seal population and the increase in the rate of sealworm infestation in cod over the last decades ... | 1987 | 30965534 |
| dental pulp exposure, periapical inflammation and suppurative osteomyelitis of the jaws in juvenile baltic grey seals (halichoerus grypus grypus) from the late 19th century. | the systematic analysis of museum collections can provide important insights into the dental and skeletal pathology of wild mammals. here we present a previously unreported type of dental defect and related skull pathology in five juvenile baltic grey seals that had been collected in the course of a seal culling program along the danish coast in 1889 and 1890. all five skulls exhibited openings into the pulp cavities at the crown tips of all (four animals) or two (one animal) canines as well as ... | 2019 | 30978237 |
| widespread neonatal infection with phocid herpesvirus 1 in free-ranging and stranded grey seals halichoerus grypus. | phocid herpesvirus 1 (phhv-1) is known to infect grey seals halichoerus grypus but little is known about its pathogenicity or true prevalence in this species. to investigate the prevalence of and risk factors associated with phv-1 infection, nasal swabs were collected from grey seal pups and yearlings on the isle of may, a well-studied grey seal breeding colony, and from stranded grey seal pups submitted to a rehabilitation centre. phhv-1 nucleic acids were detected in nasal swabs from 58% (52/9 ... | 2019 | 31019131 |
| 137cs and 40k in gray seals halichoerus grypus in the southern baltic sea. | this study presents levels of 137cs and 40k concentrations in the placentas of seals gathered in the period 2007-2015. the mean activity of 137cs and 40k was 5.49 bq kg-1w.w. and 136.6 bq kg-1 ww respectively. statistically significant correlation was observed between the 137cs activities in placenta and in herring-the staple food for seals. the concentrations of 137cs and 40k were also determined in other tissues (muscle, liver, lung, and brain) of wild seals. the concentrations of 137cs were f ... | 2019 | 31020531 |
| changes in total mercury, methylmercury, and selenium blood levels during different life history stages of the baltic grey seal (halichoerus grypus grypus). | using the blood of grey seal pups, the blood and milk of female grey seals inhabiting the hel marine station of gdansk university's institute of oceanography (hms), we monitored the transfer of total mercury (thg), methylmercury (mehg), and selenium (se) with blood during foetal life and nursing. changes in the concentration of mercury and selenium were characterised in the pups' blood during their first three months of life when they transition from suckling, to a post-weaning fast, to eating f ... | 2019 | 31048158 |
| risk of extinction of a unique skate population due to predation by a recovering marine mammal. | benefitting from reduced harvesting and an end to culling, many marine mammals are now recovering from past overexploitation. these recoveries represent important conservation successes but present a serious conservation problem when the recovering mammals are predators of species of conservation concern. here, we examine the role of predation by recovering grey seals (halichoerus grypus) in the near-extinction of a unique skate population in the southern gulf of st. lawrence (sgsl) in atlantic ... | 2019 | 31059188 |
| 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 |
| linking consumer physiological status to food-web structure and prey food value in the baltic sea. | declining physiological status in marine top consumers has been observed worldwide. we investigate changes in the physiological status and population/community traits of six consumer species/groups in the baltic sea (1993-2014), spanning four trophic levels and using metrics currently operational or proposed as indicators of food-web status. we ask whether the physiological status of consumers can be explained by food-web structure and prey food value. this was tested using partial least square ... | 2020 | 31168701 |
| formant modification through vocal production learning in gray seals. | vocal production learning is a rare communication skill and has only been found in selected avian and mammalian species [1-4]. although humans use learned formants and voiceless sounds to encode most lexical information [5], evidence for vocal learning in other animals tends to focus on the modulation pattern of the fundamental frequency [3, 4]. attempts to teach mammals to produce human speech sounds have largely been unsuccessful, most notably in extensive studies on great apes [5]. the limite ... | 2019 | 31231051 |
| memory for own behaviour in pinnipeds. | pinnipeds are aquatic predators feeding on a vast range of prey, and their social behaviour differs greatly between species (from extreme polygyny in some sea lions to monogamy in some true seals). it has been hypothesised that the foraging and social complexity of their lifestyle should drive the evolution of their cognitive abilities. to investigate how aware pinnipeds are of their own behaviour, a grey seal (halichoerus grypus), two harbour seals (phoca vitulina) and four south american sea l ... | 2019 | 31240504 |
| effects of health status on pressure-induced changes in phocid immune function and implications for dive ability. | the ability of marine mammals to cope with environmental challenges is a key determining factor in strandings and successful release of rehabilitated animals. dive behavior is related to foraging and thus survival. while dive adaptations have been well studied, it is unknown how the immune system responds to diving and whether health status impacts immune function during diving. this study investigated the functional response of ex situ immune cells from stranded phocids to in vitro increased pr ... | 2019 | 31346696 |
| microplastics in grey seal (halichoerus grypus) intestines: are they associated with parasite aggregations? | between 2012 and 2015, 13 grey seals were recovered from trammel nets targeting monkfish and rays off the south coast of ireland. incidence and distribution of microplastics were investigated along the intestines of bycaught seals. no macrodebris items were found, whereas microplastics were detected in all seals. a total of 363 microplastics items were identified (85% fibers, 14% fragments, 1% films). estimation of microplastic ingestion based on prey ingestion (245 particles) was lower than the ... | 2019 | 31426167 |
| high oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals (halichoerus grypus). | maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. oxytocin is vital for parent-offspring bonding and behaviour. it also modulates energetic balance and neural pathways regulating feeding. however, to date the connections between these two areas of the hormone's functionality are poorly defined. we demonstrate that grey seal (halichoerus grypus) mothers with high oxytocin levels produce pups with high oxytocin levels throughout lactat ... | 2019 | 31487568 |
| opportunistic detection of anthropogenic micro debris in harbor seal (phoca vitulina vitulina) and gray seal (halichoerus grypus atlantica) fecal samples from haul-outs in southeastern massachusetts, usa. | anthropogenic micro debris in the marine environment is a growing concern worldwide, affecting multiple trophic levels, from primary consumers such as zooplankton, to meso- and apex predators like marine mammals and marine birds. in 2016-2017, during the processing of harbor seal (phoca vitulina vitulina) and gray seal (halichoerus grypus atlantica) fecal samples for fish otoliths and organic hard parts as part of a prey study, anthropogenic micro debris (>500 μm) was detected in 6% (n = 2/32) o ... | 2019 | 31590801 |
| forensic microbiology reveals that neisseria animaloris infections in harbour porpoises follow traumatic injuries by grey seals. | neisseria animaloris is considered to be a commensal of the canine and feline oral cavities. it is able to cause systemic infections in animals as well as humans, usually after a biting trauma has occurred. we recovered n. animaloris from chronically inflamed bite wounds on pectoral fins and tailstocks, from lungs and other internal organs of eight harbour porpoises. gross and histopathological evidence suggest that fatal disseminated n. animaloris infections had occurred due to traumatic injury ... | 2019 | 31605019 |
| highly pathogenic avian influenza a(h5n8) virus in gray seals, baltic sea. | we detected a highly pathogenic avian influenza a(h5n8) virus in lung samples of 2 gray seals (halichoerus grypus) stranded on the baltic coast of poland in 2016 and 2017. this virus, clade 2.3.4.4 b, was closely related to avian h5n8 viruses circulating in europe at the time. | 2019 | 31742519 |
| environment-sensitive mass changes influence breeding frequency in a capital breeding marine top predator. | the trade-off between survival and reproduction in resource-limited iteroparous animals can result in some individuals missing some breeding opportunities. in practice, even with the best observation regimes, deciding whether 'missed' years represent real pauses in breeding or failures to detect breeding can be difficult, posing problems for the estimation of individual reproductive output and overall population fecundity. we corrected fecundity estimates by determining whether breeding had occu ... | 2020 | 31749170 |
| novel pulmonary vasculitis with splendore-hoeppli reaction in grey seals (halichoerus grypus) associated with otostrongylus circumlitus infection. | lungworm infection in seals is an important cause of morbidity and mortality, inducing bronchopneumonia and affecting population dynamics in some areas of the world. we present a series of cases of lungworm infection in grey seals (halichoerus grypus) associated with novel, significant and unusual pulmonary vascular changes. grey seals (n = 180) that were stranded, in rehabilitation or in long-term captivity in the uk were subjected to post-mortem examination between 2012 and 2018. lung tissue w ... | 2019 | 31812177 |
| ecological costs of climate change on marine predator-prey population distributions by 2050. | identifying and quantifying the effects of climate change that alter the habitat overlap of marine predators and their prey population distributions is of great importance for the sustainable management of populations. this study uses bayesian joint models with integrated nested laplace approximation (inla) to predict future spatial density distributions in the form of common spatial trends of predator-prey overlap in 2050 under the "business-as-usual, worst-case" climate change scenario. this w ... | 2020 | 32015865 |
| hyperbaric tracheobronchial compression in cetaceans and pinnipeds. | assessment of the compressibility of marine mammal airways at depth is crucial to understanding vital physiological processes such as gas exchange during diving. very few studies have directly assessed changes in cetacean and pinniped tracheobronchial shape, and none have quantified changes in volume with increasing pressure. a harbor seal, gray seal, harp seal, harbor porpoise and common dolphin were imaged promptly post mortem via computed tomography in a radiolucent hyperbaric chamber. volume ... | 2020 | 32041809 |
| fur and faeces - routes of mercury elimination in the baltic grey seal (halichoerus grypus grypus). | this study focused on evaluating the elimination of hg by baltic grey seals (halichoerus grypus grypus) via faeces and pelage. in addition, we investigated the potential for ecosystem contamination via these routes. faeces and fur were collected in 2014-2017 from captive adult grey seals and their pups. the concentrations of total mercury (thg) and methylmercury (mehg) were measured in the samples. the amount of mercury eliminated in a labile form (the sum of the bioavailable hg(ii) and methylme ... | 2020 | 32062253 |
| a review of pathogens in selected baltic sea indicator species. | here we review the state-of-the-art of pathogens in select marine and terrestrial key species of the baltic sea, i.e. ringed seal (pusa hispida), harbour seal (phoca vitulina), grey seal (halichoerus grypus), harbour porpoise (phocoena phocoena), common eider (somateria mollissima), pink-footed goose (anser brachyrhynchus) and white-tailed eagle (haliaeetus albicilla). this review is the first to merge and present available information and baseline data for the fp7 bonus balthealth project: balt ... | 2020 | 32070804 |
| sex-differences in fine-scale home-range use in an upper-trophic level marine predator. | the distribution of prey in the ocean is spatially and temporally patchy. how predators respond to this prey patchiness may have consequences on their foraging success, and thus physical condition. the recent ability to record fine-scale movements of marine animals combined with novel home-range analyses that incorporate the dimension of time should permit a better understanding of how individuals utilise different regions of space and the consequences on their foraging success. | 2020 | 32082578 |
| variation in individual reproductive performance amplified with population size in a long-lived carnivore. | individual variation in reproductive ability is a key component of natural selection within populations, driving the evolution of life histories and population responses to changing environmental conditions. evidence that population density affects individual-level fitness in wild populations is limited, particularly for long-lived animals, which are difficult to observe on a biologically relevant scale. we tested for individual heterogeneity in reproductive performance in female grey seals (hal ... | 2020 | 32083735 |
| toxoplasma gondii, sarcocystis sp. and neospora caninum-like parasites in seals from northern and eastern canada: potential risk to consumers. | zoonotic parasites of seals that are harvested for food may pose a health risk when seal meat or organ tissues of infected animals are eaten raw or undercooked. in this study, 124 tissue samples from 81 seals, comprising four species, were collected from northern and eastern canada. tissues from 23 ringed seals (pusa hispida), 8 hooded seals (cystophora cristata), 21 harp seals (pagophilus groenlandicus), and 29 grey seals (halichoerus grypus) were tested for parasites of the sarcocystidae famil ... | 2019 | 32095635 |
| rates of increase in gray seal (halichoerus grypus atlantica) pupping at recolonized sites in the united states, 1988-2019. | gray seals were historically distributed along the northeastern coast of the united states, but bounties and lack of protection reduced numbers and they were rarely observed for most of the 20th century. once protections were enacted, the population started to rebound. here, we describe the recolonization and recovery of gray seals in the united states, focusing on the re-establishment of pupping sites. we fit individual generalized linear models to various time series (1988-2019) to estimate ra ... | 2020 | 32099265 |
| pathological findings in north sea and baltic grey seal and harbour seal intestines associated with acanthocephalan infections. | grey seals halichoerus grypus and harbour seals phoca vitulina are common seal species in the north and baltic seas and final hosts of corynosoma acanthocephalans. c. strumosum and c. magdaleni infect the small intestines of both seal species. in contrast to harbour seals, baltic grey seals in the past have regularly displayed severe c. semerme infections in the caecum and colon, with associated tunica muscularis hypertrophy, inflammation and ulcerations as part of the baltic seal disease comple ... | 2020 | 32103824 |
| deiminated proteins and extracellular vesicles as novel biomarkers in pinnipeds: grey seal (halichoerus gryptus) and harbour seal (phoca vitulina). | peptidylarginine deiminases (pads) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, leading to functional and structural changes in target proteins. protein deimination can cause the generation of neo-epitopes, affect gene regulation and also allow for protein moonlighting and therefore facilitate multifaceted functions of the same protein. pads are furthermore a key regulator of cel ... | 2020 | 32105816 |
| polychlorinated biphenyls (pcbs) and sex hormone concentrations in ringed and grey seals: a possible link to endocrine disruption? | polychlorinated biphenyls (pcbs) are recognised reproductive and immune system toxicants in marine mammals mediated by endocrine-disrupting mechanisms. as with other predators, seals are exposed to elevated bioaccumulated concentrations of pcbs and other persistent organic pollutants (pops). cryopreserved plasma samples from adult ringed (phoca hispida; n = 39) and grey (halichoerus grypus; n = 38) seals, sampled between 1998 and 2002 from baltic sea, svalbard, and sable island (canada) were use ... | 2020 | 32107597 |