| reprint of: temporal trends of polyfluoroalkyl compounds (pfcs) in liver tissue of grey seals (halichoerus grypus) from the baltic sea, 1974-2008. | temporal trends of polyfluoroalkyl compounds (pfcs) were examined in grey seal (halichoerus grypus) liver from the baltic sea over a period of 35 years (1974-2008). in total, 17 of 43 pfcs were found, including the perfluoroalkyl sulfonates (c(4)-c(10) pfsas), perfluorooctanesulfinate (pfosi), long chain perfluoroalkyl carboxylates (c(7)-c(14) pfcas), and perfluoroalkyl sulfonamides (i.e., perfluorooctane sulfonamide (fosa) and n-ethyl perfluorooctane sulfonamide (etfosa)), whereas saturated and ... | 2011 | 21944042 |
| Effects of handling regime and sex on changes in cortisol, thyroid hormones and body mass in fasting grey seal pups. | Survival of seal pups may be affected by their ability to respond appropriately to stress. Chronic stress can adversely affect secretion of cortisol and thyroid hormones, which contribute to the control of fuel utilisation. Repeated handling could disrupt the endocrine response to stress and/or negatively impact upon mass changes during fasting. Here we investigated the effects of handling regime on cortisol and thyroid hormone levels, and body mass changes, in fasting male and female grey seal ... | 2012 | 21945943 |
| Indications for both host-specific and introduced genotypes of Staphylococcus aureus in marine mammals. | Staphylococcus aureus is present in the marine environment and causes disease in marine mammals. To determine whether marine mammals are colonized by host-specific strains or by strains originating from other species, we performed multi-locus sequence typing on ten S. aureus strains isolated from marine mammals in the U.K., the Netherlands, and the Antarctic. Four new sequence types of S. aureus were discovered. S. aureus strains from a southern elephant seal (n=1) and harbour porpoises (n=2) di ... | 2011 | 22112853 |
| how many seals were there? the global shelf loss during the last glacial maximum and its effect on the size and distribution of grey seal populations. | predicting how marine mammal populations respond to habitat changes will be essential for developing conservation management strategies in the 21st century. responses to previous environmental change may be informative in the development of predictive models. here we describe the likely effects of the last ice age on grey seal population size and distribution. we use satellite telemetry data to define grey seal foraging habitat in terms of the temperature and depth ranges exploited by the contem ... | 2012 | 23300843 |
| 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 ... | 2012 | 23272350 |
| 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 ... | 2014 | 25533658 |
| offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals. | offspring size affects survival and subsequent reproduction in many organisms. however, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. we used data from a long-term study of individually marked gray seals (halichoerus grypus; fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspr ... | 2015 | 25897381 |
| 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 |
| 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 |
| occurrence of zoonotic nematodes pseudoterranova decipiens, contracaecum osculatum and anisakis simplex in cod (gadus morhua) from the baltic sea. | baltic cod gadus morhua (a total of total 224 specimens) captured east of the island of bornholm in the southern baltic sea were subjected to a parasitological investigation between march 2013 and april 2014. full artificial digestion of fillets from 188 cod and additional investigation of livers from 36 cod were performed. cod or seal worm pseudoterranova decipiens was recorded in musculature (prevalences up to 55% and intensities up to 56 worms per fish) associated with a negative correlation ... | 2014 | 25224792 |
| 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. ... | 2014 | 24570064 |
| evidence of land-sea transfer of the zoonotic pathogen campylobacter to a wildlife marine sentinel species. | environmental pollution often accompanies the expansion and urbanization of human populations where sewage and wastewaters commonly have an impact on the marine environments. here, we explored the potential for faecal bacterial pathogens, of anthropic origin, to spread to marine wildlife in coastal areas. the common zoonotic bacterium campylobacter was isolated from grey seals (halichoerus grypus), an important sentinel species for environmental pollution, and compared to isolates from wild bird ... | 2015 | 25401947 |
| 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 ... | 2013 | 23505705 |
| 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 |
| 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 |
| [infestation rates of the main commercial fish species with larvae of contracaecum osculatum (rudolphi, 1802) (nematoda: anisakidae) in russian waters of the south baltic in 2000-2012]. | the infestation dynamic of the sprat (sprattus sprattus balticus), the baltic herring (clupea harengus membras), and the baltic cod (gadus morhua callaris) with nematodes contracaecum osculatum 1 (anisakidae) from russian waters of the south baltic were studied in 2000-2012. peculiarities of larval growth in different hosts were analyzed. a total of 6233 fish specimens were investigated, including 1420, 3867, and 946 specimens of sprat, herring, and cod, respectively. the prevalence and mean int ... | 2015 | 25693327 |
| sealworm (pseudoterranova decipiens) infection in grey seals (halichoerus grypus), cod (gadus morhua) and shorthorn sculpin (myoxocephalus scorpius) in the baltic sea. | the anisakid nematode pseudoterranova decipiens, known as the sealworm or cod worm, can infect the flesh of several fish species. the parasite causes cosmetic problems for the fish industry and can cause abdominal discomfort if consumed by humans. there are only scattered studies on the abundance or distribution of the sealworm in fish and seals in the baltic sea. to remedy this situation, the extent of sealworm infection was investigated in cod (gadus morhua) and shorthorn sculpin (myoxocephalu ... | 2015 | 25367209 |
| increased contracaecum osculatum infection in baltic cod (gadus morhua) livers (1982-2012) associated with increasing grey seal (halichoerus gryphus) populations. | grey seals (halichoerus gryphus), the main final host of the gastric parasitic nematode contracaecum osculatum in the baltic, have recently recolonized the southwestern baltic sea. this colonization could lead to an increase in prevalence and intensity of third-stage larvae of c. osculatum in livers of baltic cod (gadus morhua), which serve as transport host for this helminth. we performed a parasitologic study of cod in spring 2012 and compared the results with previously unpublished data from ... | 2014 | 24779467 |
| 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 |
| 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 |
| 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 ... | 2014 | 25390639 |
| 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 |
| canid progesterone receptors lack activation function 3 domain-dependent activity. | progesterone regulates multiple behavioral, physiological, and pathological aspects of female reproductive biology through its two progesterone receptors (prs), pr-b and the truncated pr-a. pr-b is necessary for mammary gland development in mice and, compared with pr-a, is overall a stronger transactivator of target genes due to an additional activation function 3 (af3) domain. in dogs, known for their high sensitivity to progesterone-induced mammary cancer, the pr-b function was studied. canine ... | 2012 | 23041671 |
| mycobacterium bovis infection in a grey seal pup (halichoerus grypus). | | 2013 | 23764843 |
| 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 |
| 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 ... | 2015 | 25647591 |
| patterns of stranding and mortality in common seals (phoca vitulina) and grey seals (halichoerus grypus) in the netherlands between 1979 and 2008. | pathological examination of stranded marine mammals provides information on the causes of mortality in their populations. patterns of stranding and causes of death of dead-stranded seals on the dutch coast were analyzed over a 30-year period (1979-2008). stranding data (n=1,286) and post-mortem data (n=379) from common seals (phoca vitulina) and grey seals (halichoerus grypus) found dead, or that died before admission to rehabilitation, were obtained from the seal rehabilitation and research cen ... | 2012 | 22632685 |
| 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 |
| emerging pseudoterranova decipiens (krabbe, 1878) problems in baltic cod, gadus morhua l., associated with grey seal colonization of spawning grounds. | | 2012 | 22817526 |
| clinical challenge: systemic rhizopus microsporus infection with renal cavitation in a grey seal (halichoerus grypus). | | 2013 | 24450087 |
| analysis of streptococcus agalactiae pan-genome for prevalence, diversity and functionality of integrative and conjugative or mobilizable elements integrated in the trna(lys ctt) gene. | streptococcus agalactiae is the first cause of invasive infections in human neonates and is also a major bovine and fish pathogen. high genomic diversity was observed in this species that hosts numerous mobile genetic elements, in particular elements transferable by conjugation. this works aims to evaluate the contribution of these elements to gbs genome diversity. focusing on genomic islands integrated in the trna(lys) (ctt) gene, a known hotspot of recombination, an extensive in silico search ... | 2015 | 25832353 |
| human streptococcus agalactiae strains in aquatic mammals and fish. | in humans, streptococcus agalactiae or group b streptococcus (gbs) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. in addition, streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. we studied the molecular epidemiology of s. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic s ... | 2013 | 23419028 |
| human pathogens in marine mammal meat – a northern perspective. | only a few countries worldwide hunt seals and whales commercially. in norway, hooded and harp seals and minke whales are commercially harvested, and coastal seals (harbour and grey seals) are hunted as game. marine mammal meat is sold to the public and thus included in general microbiological meat control regulations. slaughtering and dressing of marine mammals are performed in the open air on deck, and many factors on board sealing or whaling vessels may affect meat quality, such as the ice use ... | 2014 | 24344685 |
| 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 |
| spatial distribution of fishes in a northwest atlantic ecosystem in relation to risk of predation by a marine mammal. | 1. numerous studies have shown that, at spatial scales of metres to several kilometres, animals balance the trade-off between foraging success and predation mortality by increasing their use of safer but less profitable habitats as predation risk increases. however, it is less clear whether prey respond similarly at the larger spatiotemporal scales of many ecosystems. 2. we determine whether this behaviour is evident in a large marine ecosystem, the southern gulf of st. lawrence (sgsl, 75 000 km ... | 2015 | 25976520 |
| 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 |
| 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 |
| 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 ... | 1997 | 23899212 |
| 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 |
| isolation and phylogenetic characterization of streptococcus halichoeri from a european badger (meles meles) with pyogranulomatous pleuropneumonia. | clinical and pathological studies in european badgers (meles meles) are limited. badgers play a significant role in the epidemiology of bovine tuberculosis (tb) in some countries and an accurate diagnosis is needed for this infection. however, the lesions of bovine tb are similar to those associated with other pathogens, making pathological diagnosis difficult. in the present study, streptococcus halichoeri was isolated from a european badger with pyogranulomatous pleuropneumonia and suspected o ... | 2015 | 25678424 |
| the use of dna barcoding to monitor the marine mammal biodiversity along the french atlantic coast. | in the last ten years, 14 species of cetaceans and five species of pinnipeds stranded along the atlantic coast of brittany in the north west of france. all species included, an average of 150 animals strand each year in this area. based on reports from the stranding network operating along this coast, the most common stranding events comprise six cetacean species (delphinus delphis, tursiops truncatus, stenella coeruleoalba, globicephala melas, grampus griseus, phocoena phocoena)and one pinniped ... | 2013 | 24453548 |
| improved reproductive success in otters (lutra lutra), grey seals (halichoerus grypus) and sea eagles (haliaeetus albicilla) from sweden in relation to concentrations of organochlorine contaminants. | we studied indices of reproductive outcome in three aquatic species in relation to organochlorine concentrations during four decades. in female otters, the frequency of signs of reproduction increased after 1990. in grey seals, pregnancy rate increased 1990-2010 and uterine obstructions ceased after 1993. the frequency of uterine tumours was highest 1980-2000. the number of sea eagle nestlings per checked nest increased 1985-2000, while the frequency of desiccated eggs decreased. organochlorine ... | 2012 | 22842056 |
| 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 |
| chlorinated herbicides in fish, birds and mammals in the baltic sea. | the aim of the present work was to determine the concentration levels, as well as accumulation and magnification coefficients, of triazine derivatives in herring gulls and baltic grey seals 11 years after a ban on their use in the eu and eight after their exclusion in poland. dead birds were collected in the coastal zone of the gulf of gdansk in the years 2010-2012. the grey seals, on the other hand, were from before 2007, when s-triazine derivatives were still in use. triazine herbicides (atraz ... | 2017 | 26246644 |
| 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 |
| effects of a large northern european no-take zone on flatfish populations. | in march 2006, a 360 km² no-take zone (ntz) was established north of gotland in the central baltic sea, with the purpose to scientifically evaluate the effects of a fishing ban on flatfish populations. a monitoring programme was set up to study the populations in the ntz and in a reference area east of gotland where the fishing pressure was high. the programme included fishing with multimesh survey nets, modelling of potential larval export and estimation of fish consumption by large marine pred ... | 2013 | 24090556 |
| 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 |
| levels of alpha-hch, lindane, and enantiomeric ratios of alpha-hch in marine mammals from the northern hemisphere. | the enantiomeric ratios of alpha-hch were determined by chiral gas chromatography in blubber of marine mammals from regions of the northern hemisphere (north sea, baltic sea, arctic and iceland). cetaceans (harbour porpoises and white-beaked dolphins) showed a preferential accumulation of (+)-alpha-hch. in blubber of harbour seals, grey seals and harp seals (+)-alpha-hch was also more abundant than (-)-alpha-hch. hooded seals formed an exception with a (+/-) enantiomeric ratio of alpha-hch < 1. | 1995 | 8528649 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| bite injuries of grey seals (halichoerus grypus) on harbour porpoises (phocoena phocoena). | bite-like skin lesions on harbour porpoises (phocoena phocoena) have been suspected to be caused by grey seals (halichoerus grypus), and a few field observations have been reported. bite-like skin lesions observed on stranded animals were characterized by two main components: large flaps of loose or missing skin and blubber with frayed edges and puncture lesions. definitive demonstration of predation by a grey seal was not reported so far in those stranded animals. in this study, five stranded p ... | 2014 | 25461599 |
| exposing the grey seal as a major predator of harbour porpoises. | harbour porpoises (phocoena phocoena) stranding in large numbers around the southern north sea with fatal, sharp-edged mutilations have spurred controversy among scientists, the fishing industry and conservationists, whose views about the likely cause differ. the recent detection of grey seal (halichoerus grypus) dna in bite marks on three mutilated harbour porpoises, as well as direct observations of grey seal attacks on porpoises, have identified this seal species as a probable cause. bite mar ... | 2015 | 25429021 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 ... | 2012 | 23001684 |
| organochlorine contamination in pinnipeds. | organochlorines, such as pcbs and ddt, are ubiquitous contaminants. most studies reporting concentrations of organochlorines in pinnipeds have investigated ringed, grey, and harbour seals. very few studies have been carried out on pinnipeds from the southern hemisphere. pre-1980, the highest mean wet-weight blubber concentrations of ddt and related metabolites (911 +/- 582 micrograms g-1) were recorded in sea lions from california. the highest pre-1980 blubber concentrations of pcbs (1470 +/- 92 ... | 1994 | 8029490 |
| growth in pinnipeds. | this review presents summary figures of, and fits growth curves to, data on body lengths (as standard length, sl, whenever possible) of pinnipeds at ages estimated to o.i y. (1) generalized von bertalanffy (vb) growth curves are fitted to most data: lx = l infinity (i - ea(x-x0)b, lx is length at age x, x0 is the origin of the curve (here chosen a priori as time of initiation of embryonic growth), l infinity is asymptotic length, a (which is negative) determines rate of approach to the asymptote ... | 1993 | 8457634 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| conspecific recognition and aggression reduction to familiars in newly weaned, socially plastic mammals. | recognising conspecifics and behaving appropriately towards them is a crucial ability for many species. grey seals (halichoerus grypus) show varying capabilities in this regard: mother-pup recognition has been demonstrated in some geographical populations but is absent in others, yet there is evidence that individuals aggregate with prior associates. the recognition capabilities of newly weaned grey seal pups were investigated using class recognition trials within the habituation/dishabituation ... | 2017 | 26246656 |
| a novel approach to quantifying the spatiotemporal behavior of instrumented grey seals used to sample the environment. | paired with satellite location telemetry, animal-borne instruments can collect spatiotemporal data describing the animal's movement and environment at a scale relevant to its behavior. ecologists have developed methods for identifying the area(s) used by an animal (e.g., home range) and those used most intensely (utilization distribution) based on location data. however, few have extended these models beyond their traditional roles as descriptive 2d summaries of point data. here we demonstrate h ... | 2015 | 26213626 |
| trends in stranding and by-catch rates of gray and harbor seals along the northeastern coast of the united states: evidence of divergence in the abundance of two sympatric phocid species? | harbor seals and gray seals are sympatric phocid pinnipeds found in coastal waters of the temperate and sub-arctic north atlantic. in the northwest atlantic, both species were depleted through a combination of subsistence hunts and government supported bounties, and are now re-occupying substantial portions of their original ranges. while both species appear to have recovered during the past 2 decades, our understanding of their population dynamics in us waters is incomplete. here we describe tr ... | 2015 | 26200461 |
| a novel tool to mitigate by-catch mortality of baltic seals in coastal fyke net fishery. | developing methods to reduce the incidental catch of non-target species is important, as by-catch mortality poses threats especially to large aquatic predators. we examined the effectiveness of a novel device, a "seal sock", in mitigating the by-catch mortality of seals in coastal fyke net fisheries in the baltic sea. the seal sock developed and tested in this study was a cylindrical net attached to the fyke net, allowing the seals access to the surface to breathe while trapped inside fishing ge ... | 2015 | 25993534 |
| adiponectin and insulin in gray seals during suckling and fasting: relationship with nutritional state and body mass during nursing in mothers and pups. | animals that fast during breeding and/or development, such as phocids, must regulate energy balance carefully to maximize reproductive fitness and survival probability. adiponectin, produced by adipose tissue, contributes to metabolic regulation by modulating sensitivity to insulin, increasing fatty acid oxidation by liver and muscle, and promoting adipogenesis and lipid storage in fat tissue. we tested the hypotheses that (1) circulating adiponectin, insulin, or relative adiponectin gene expres ... | 2015 | 25860828 |
| distance measures and optimization spaces in quantitative fatty acid signature analysis. | quantitative fatty acid signature analysis has become an important method of diet estimation in ecology, especially marine ecology. controlled feeding trials to validate the method and estimate the calibration coefficients necessary to account for differential metabolism of individual fatty acids have been conducted with several species from diverse taxa. however, research into potential refinements of the estimation method has been limited. we compared the performance of the original method of ... | 2015 | 25859330 |
| 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 ... | 2015 | 25524165 |
| by-catch of grey seals (halichoerus grypus) in baltic fisheries--a bayesian analysis of interview survey. | baltic seals are recovering after a population decline. the increasing seal stocks cause notable damage to fisheries in the baltic sea, with an unknown number of seals drowning in fishing gear every year. thus, sustainable seal management requires updated knowledge of the by-catch of seals--the number of specimens that die in fishing gear. we analyse the by-catch of grey seals (halichoerus grypus) in finland, sweden, and estonia in 2012. we collect data with interviews (35 in finland, 54 in swed ... | 2014 | 25423168 |
| grey seals use anthropogenic signals from acoustic tags to locate fish: evidence from a simulated foraging task. | anthropogenic noise can have negative effects on animal behaviour and physiology. however, noise is often introduced systematically and potentially provides information for navigation or prey detection. here, we show that grey seals (halichoerus grypus) learn to use sounds from acoustic fish tags as an indicator of food location. in 20 randomized trials each, 10 grey seals individually explored 20 foraging boxes, with one box containing a tagged fish, one containing an untagged fish and all othe ... | 2015 | 25411449 |
| hsp70 abundance and antioxidant capacity in feeding and fasting gray seal pups: suckling is associated with higher levels of key cellular defenses. | heat shock proteins (hsps) and antioxidants are key cellular defenses against stress. seals routinely undergo protracted fasting, which is normally associated with physiological stress in other animals. we tested the hypotheses that (1) relative hsp70 protein abundance is higher in liver and blubber of fasting relative to suckling wild gray seal pups; (2) differences in hsp70 are mirrored in tissue superoxide dismutase (sod) and catalase activity, as well as glutathione levels; (3) extracellular ... | 2014 | 25244378 |
| molecular biomarkers in grey seals (halichoerus grypus) to evaluate pollutant exposure, health and immune status. | grey seals as top-predators bioaccumulate contaminants and can be considered as sentinels of eco-system health. pups are weaned after a short nursing period, characterised by an enormous lipid transfer and exposure to contaminants. this study established molecular biomarkers of the xenobiotic metabolism and immune system to help assess health and immune status. mrna transcription of ahr, arnt, pparα and cytokine il-2 and heat-shock-protein hsp70 was measured in blood of grey seal pups and adults ... | 2014 | 25220314 |
| an optimized computed tomography protocol for metallic gunshot head trauma in a seal model. | computed tomography (ct) is commonly used to assess animals with head trauma. however, strongly attenuating objects such as metallic gunshot cause artifacts that may make accurate localization of shrapnel pieces difficult. the purpose of this study was to develop an optimized ct protocol for minimizing metal artifacts in an animal model of gunshot head trauma. a cadaver head of a stranded gray seal (halichoerus grypus) was shot post-mortem with a 0.223-inch caliber rifle. the head was frozen, th ... | 2016 | 25184173 |
| global population structure and demographic history of the grey seal. | although the grey seal halichoerus grypus is one of the most familiar and intensively studied of all pinniped species, its global population structure remains to be elucidated. little is also known about how the species as a whole may have historically responded to climate-driven changes in habitat availability and anthropogenic exploitation. we therefore analysed samples from over 1500 individuals collected from 22 colonies spanning the western and eastern atlantic and the baltic sea regions, r ... | 2014 | 25041117 |
| probability of detecting marine predator-prey and species interactions using novel hybrid acoustic transmitter-receiver tags. | understanding the nature of inter-specific and conspecific interactions in the ocean is challenging because direct observation is usually impossible. the development of dual transmitter/receivers, vemco mobile transceivers (vmt), and satellite-linked (e.g. gps) tags provides a unique opportunity to better understand between and within species interactions in space and time. quantifying the uncertainty associated with detecting a tagged animal, particularly under varying field conditions, is vita ... | 2014 | 24892286 |
| 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 ... | 2014 | 24845148 |
| in-air evoked potential audiometry of grey seals (halichoerus grypus) from the north and baltic seas. | in-air anthropogenic sound has the potential to affect grey seal (halichoerus grypus) behaviour and interfere with acoustic communication. in this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (abr) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. thresholds were measured at 10 frequencies between 1-20 khz. measu ... | 2014 | 24632891 |
| 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. | 2014 | 24485867 |
| behavioral responses by grey seals (halichoerus grypus) to high frequency sonar. | the use of high frequency sonar is now commonplace in the marine environment. most marine mammals rely on sound to navigate, and for detecting prey, and there is the potential that the acoustic signals of sonar could cause behavioral responses. to investigate this, we carried out behavioral response tests with grey seals to two sonar systems (200 and 375 khz systems). results showed that both systems had significant effects on the seals behavior; when the 200 khz sonar was active, seals spent si ... | 2014 | 24445129 |
| a study on the effect of different rifle calibres in euthanisation of grey seals (halichoerus grypus) in seal traps in the baltic sea. | in recent years, the euthanasia of seals has been discussed internationally and concern has been raised regarding the use of rifles, the effect of different calibres, and which calibres are sufficient for humane euthanasia. this study therefore investigated the effect of different firearm calibres on euthanasia of grey seals (halichoerus grypus) in traps, and provides information for the development and refinement of regulations for hunting seals in the wild. | 2013 | 24219864 |
| behavioral signature of intraspecific competition and density dependence in colony-breeding marine predators. | in populations of colony-breeding marine animals, foraging around colonies can lead to intraspecific competition. this competition affects individual foraging behavior and can cause density-dependent population growth. where behavioral data are available, it may be possible to infer the mechanism of intraspecific competition. if these mechanics are understood, they can be used to predict the population-level functional response resulting from the competition. using satellite relocation and dive ... | 2013 | 24198943 |
| control control control: a reassessment and comparison of genbank and chromatogram mtdna sequence variation in baltic grey seals (halichoerus grypus). | genetic data can provide a powerful tool for those interested in the biology, management and conservation of wildlife, but also lead to erroneous conclusions if appropriate controls are not taken at all steps of the analytical process. this particularly applies to data deposited in public repositories such as genbank, whose utility relies heavily on the assumption of high data quality. here we report on an in-depth reassessment and comparison of genbank and chromatogram mtdna sequence data gener ... | 2013 | 23977362 |