| selective blubber fatty acid mobilization in lactating gray seals (halichoerus grypus). | during negative energy balance periods, fatty acids (fas) are mobilized to cover the metabolic demands of the body. fas from adipose tissue are selectively mobilized according to their carbon length (cl) and number of double bonds (dbs); however, studies in vivo have focused only on fasting and nonlactating animals. during lactation, uk gray seals fast for 18 d, mobilizing a large amount of lipid from blubber to sustain their own metabolic demands and the nutritional requirements of pups. we inv ... | 2013 | 23799838 |
| liver glucose-6-phosphatase proteins in suckling and weaned grey seal pups: structural similarities to other mammals and relationship to nutrition, insulin signalling and metabolite levels. | phocid seals have been proposed as models for diabetes because they exhibit limited insulin response to glucose, high blood glucose and increasing insulin resistance when fasting. liver glucose-6-phosphatase (g6pase) catalyses the final step in glucose production and is central to glucose regulation in other animals. g6pase comprises a translocase (slc37a4) and a catalytic subunit (g6pc). g6pc and slc37a4 expression and activity are normally regulated by nutritional state and glucostatic hormone ... | 2013 | 23743798 |
| habitat-mediated dive behavior in free-ranging grey seals. | understanding the links between foraging behaviour and habitat use of key species is essential to addressing fundamental questions about trophic interactions and ecosystem functioning. eight female grey seals (halichoerus grypus) were equipped with time-depth recorders linked to fastloc gps tags following the annual moult in southwest ireland. individual dives were coupled with environmental correlates to investigate the habitat use and dive behaviour of free-ranging seals. dives were characteri ... | 2013 | 23667663 |
| imaging diagnosis-ultrasonographic and ct findings in a gray seal (halichoerus grypus) with hepatic cirrhosis, pyelonephritis, and nephrolithiasis. | an immature gray seal was presented with lethargy, weight loss, vomiting and hematuria. hepatic disease and urinary tract infection were suspected. abdominal ultrasound showed hyperechoic structures with marked acoustic shadowing spread throughout both kidneys, but incomplete visualization of the liver. abdominal ct showed mineral densities scattered throughout both kidneys and poor delineation of the liver. due to the poor quality of life, the seal was euthanized. postmortem examination showed ... | 2016 | 23578275 |
| the role of glucocorticoids in naturally fasting grey seal (halichoerus grypus) pups: dexamethasone stimulates mass loss and protein utilisation, but not departure from the colony. | seals must manage their energy reserves carefully while they fast on land to ensure that they go to sea with sufficient fuel to sustain them until they find food. glucocorticoids (gcs) have been implicated in the control of fuel metabolism and termination of fasting in pinnipeds. here we tested the hypothesis that dexamethasone, an artificial gc, increases fat and protein catabolism, and induces departure from the breeding colony in wild, fasting grey seal pups. a single intramuscular dose of de ... | 2013 | 23197086 |
| cyclic volatile methylsiloxanes in fish from the baltic sea. | laboratory studies suggest that the cyclic volatile methylsiloxanes (cvms) octamethylcyclotetrasiloxane (d4), decamethylcyclopentasiloxane (d5) and dodecamethylcyclohexasiloxane (d6) will persist in the aquatic environment and bioaccumulate in fish. here these cvms were measured in herring collected in the swedish waters of the baltic sea and the north sea and in grey seals from the baltic proper. d4, d5, and d6 were present in herring muscle at concentrations around 10, 200, and 40ngg(-1) lipid ... | 2013 | 23177719 |
| variation in female grey seal (halichoerus grypus) reproductive performance correlates to proactive-reactive behavioural types. | consistent individual differences (cids) in behaviour, indicative of behavioural types or personalities, have been shown in taxa ranging from cnidaria to mammalia. however, despite numerous theoretical explanations there remains limited empirical evidence for selective mechanisms that maintain such variation within natural populations. we examined behavioural types and fitness proxies in wild female grey seals at the north rona breeding colony. experiments in 2009 and 2010 employed a remotely-co ... | 2012 | 23166723 |
| animal-borne acoustic transceivers reveal patterns of at-sea associations in an upper-trophic level predator. | satellite telemetry data have substantially increased our understanding of habitat use and foraging behaviour of upper-trophic marine predators, but fall short of providing an understanding of their social behaviour. we sought to determine whether novel acoustic and archival gps data could be used to examine at-sea associations among grey seals (halichoerus grypus) during the fall foraging period. fifteen grey seals from sable island, canada were deployed with vemco mobile transceivers and satel ... | 2012 | 23155435 |
| surgical repair of a tibial fracture in a two-week-old grey seal (halichoerus grypus). | to report the successful management of a suspected infected tibial fracture in a common grey seal. | 2013 | 23154822 |
| entanglement of grey seals halichoerus grypus at a haul out site in cornwall, uk. | entanglement in marine debris has been internationally recognised as a potential threat to marine species. sightings records and a photo identification catalogue from a haul out site in southwest england were used to establish entanglement records for grey seals halichoerus grypus. between 2004 and 2008 the annual mean entanglement rates varied from 3.6% to 5%. the maximum recapture period for entangled seals compared to paired control seals was significantly less (p=0.045) suggesting an increas ... | 2012 | 23117201 |
| effects of polychlorobiphenyls, polybromodiphenylethers, organochlorine pesticides and their metabolites on vitamin a status in lactating grey seals. | polychlorobiphenyls (pcbs), polybromodiphenylethers (pbdes) and organochlorine pesticides (ocps), such as dichlorodiphenyltrichloroethane (ddt) and hexachlorobenzene (hcb), are considered as endocrine disruptors in laboratory and wild animals. this study investigated whether these compounds and their hydroxylated metabolites (ho-pcbs and ho-pbdes) may affect the homoeostasis of vitamin a, a dietary hormone, in the blubber and serum of twenty lactating grey seals sampled at early and late lactati ... | 2013 | 23051620 |
| sink fast and swim harder! round-trip cost-of-transport for buoyant divers. | efficient locomotion between prey resources at depth and oxygen at the surface is crucial for breath-hold divers to maximize time spent in the foraging layer, and thereby net energy intake rates. the body density of divers, which changes with body condition, determines the apparent weight (buoyancy) of divers, which may affect round-trip cost-of-transport (cot) between the surface and depth. we evaluated alternative predictions from external-work and actuator-disc theory of how non-neutral buoya ... | 2012 | 23014571 |
| changes in trace elements during lactation in a marine top predator, the grey seal. | lactation in pinnipeds represents the most significant cost to mothers during the reproductive cycle. dynamics of trace elements and their mobilization associated with energy reserves during such an intense physiological process remains poorly understood in marine mammals. the changes in tissue concentrations of 11 elements (ca, cd, cr, cu, fe, hg, ni, pb, se, v, and zn) were investigated in a longitudinal study during the lactation period and during the post-weaning fast period. blood, milk, bl ... | 2013 | 23010392 |
| mhc genotype and near-deterministic mortality in grey seals. | the major histocompatability complex (mhc) is one of the best known and best characterised components of the immune system, yet its functions remain somewhat enigmatic, including both anti-pathogen activity and kin recognition. to explore the importance of the mhc relative to literally hundreds of other components of the immune system, we compared mhc genotype frequencies between pups and adults in the grey seal (halichoerus grypus), one of many marine mammals that exhibit low allelic diversity. ... | 2012 | 22997548 |
| primiparous and multiparous females differ in mammary gland alveolar development: implications for milk production. | mammary gland capacity is influenced by the number of secretory cells in the gland, the activity of those cells and the size and arrangement of the alveoli that they form. although reproductive experience has been shown to affect the total number of secretory cells in the gland, its potential effect on the structural development of lobulo-alveolar tissues has not been directly investigated. to examine whether reproductive experience affects lobulo-alveolar development, we took mammary gland biop ... | 2012 | 22837465 |
| selective transfer of persistent organic pollutants and their metabolites in grey seals during lactation. | twenty grey seal (halichoerus grypus) mother-pup pairs from the colony of the isle of may (scotland) were sampled at early and late lactation in order to study the transfer of polychlorinated biphenyls (pcbs), polybrominated diphenyl ethers (pbdes) and their metabolites (ho-pcbs and ho-pbdes) as well as organochlorine pesticides (ocps), such as ddt and metabolites (ddxs) and hexachlorobenzene (hcb). the transfer of the naturally produced meo-pbdes was also investigated. generally, concentrations ... | 2012 | 22659007 |
| phocid seal leptin: tertiary structure and hydrophobic receptor binding site preservation during distinct leptin gene evolution. | the cytokine hormone leptin is a key signalling molecule in many pathways that control physiological functions. although leptin demonstrates structural conservation in mammals, there is evidence of positive selection in primates, lagomorphs and chiropterans. we previously reported that the leptin genes of the grey and harbour seals (phocids) have significantly diverged from other mammals. therefore we further investigated the diversification of leptin in phocids, other marine mammals and terrest ... | 2012 | 22536379 |
| fused traditional and geometric morphometrics demonstrate pinniped whisker diversity. | vibrissae (whiskers) are important components of the mammalian tactile sensory system, and primarily function as detectors of vibrotactile information from the environment. pinnipeds possess the largest vibrissae among mammals and their vibrissal hair shafts demonstrate a diversity of shapes. the vibrissae of most phocid seals exhibit a beaded morphology with repeating sequences of crests and troughs along their length. however, there are few detailed analyses of pinniped vibrissal morphology, a ... | 2012 | 22509310 |
| likely effects of construction of scroby sands offshore wind farm on a mixed population of harbour phoca vitulina and grey halichoerus grypus seals. | scroby sands offshore wind farm was built close to a haul-out and breeding site for harbour seal, a species of conservation concern. an aerial survey programme conducted during a five-year period spanning wind farm construction, revealed a significant post-construction decline in haul-out counts. multivariate model selection suggested that the decline was not related to the environmental factors considered, nor did it mirror wider population trends. although cause and effect could not be unequiv ... | 2012 | 22333892 |
| detecting density dependence in recovering seal populations. | time series of abundance estimates are commonly used for analyses of population trends and possible shifts in growth rate. we investigate if trends in age composition can be used as an alternative to abundance estimates for detection of decelerated population growth. both methods were tested under two forms of density dependence and different levels of environmental variation in simulated time series of growth in baltic gray seals. under logistic growth, decelerating growth could be statisticall ... | 2011 | 21404823 |
| blood cell composition of gray seals of different ages. | | 2016 | 20665155 |
| comparative sensitivity of harbour and grey seals to several environmental contaminants using in vitro exposure. | in this study, we investigated the effects of cadmium chloride (cdcl(2)), mercury chloride (hgcl(2)), methylmercury chloride (ch(3)hgcl), and pcbs on lymphocyte proliferation in phocids. pbmcs isolated from harbour and grey seals were exposed in vitro to varying concentrations of contaminants. a reduction of viability occurred when cells were exposed to 10(-4)m hgcl(2) or ch(3)hgcl or to 50ppm of aroclor 1254. in both grey and harbour seals, t-lymphocyte proliferation was suppressed when their c ... | 2010 | 19945719 |
| how fast does a seal swim? variations in swimming behaviour under differing foraging conditions. | the duration of breath-hold dives and the available time for foraging in submerged prey patches is ultimately constrained by oxygen balance. there is a close relationship between swim speed and oxygen utilisation, so it is likely that breath-holding divers optimise their speeds to and from the feeding patch to maximise time spent feeding at depth. optimal foraging models suggest that transit swim speed should decrease to minimum cost of transport (mct) speed in deeper and longer duration dives. ... | 2007 | 17766306 |
| eat now, pay later? evidence of deferred food-processing costs in diving seals. | seals may delay costly physiological processes (e.g. digestion) that are incompatible with the physiological adjustments to diving until after periods of active foraging. we present unusual profiles of metabolic rate (mr) in grey seals measured during long-term simulation of foraging trips (4-5 days) that provide evidence for this. we measured extremely high mrs (up to almost seven times the baseline levels) and high heart rates during extended surface intervals, where the seals were motionless ... | 2007 | 17443975 |
| stomach temperature telemetry reveals temporal patterns of foraging success in a free-ranging marine mammal. | 1. we studied feeding frequency in free-ranging grey seals using stomach temperature telemetry to test if previously reported sex differences in the diving, movement and diet were reflected in the temporal pattern of foraging success. 2. data were retrieved from 21 of 32 grey seals from 1999 to 2001, totalling 343 days and 555 feeding events, with individual record length varying from 2 to 40 days (mean: 16.33 +/- 2.67 days/seal). 3. seals fed on 57.8 +/- 6.46% of days sampled and had an average ... | 2006 | 16637994 |
| seasonal variation in the metabolic rate and body composition of female grey seals: fat conservation prior to high-cost reproduction in a capital breeder? | many animals rely on stored energy through periods of high energy demand or low energy availability or both. a variety of mechanisms may be employed to attain and conserve energy for such periods. wild grey seals demonstrate seasonal patterns of energy storage and foraging behaviour that appear to maximize the allocation of energy to reproduction--a period characterized by both high energy demand and low food availability. we examined seasonal patterns in resting rates of oxygen consumption as a ... | 2006 | 16506041 |
| an unexpected parallelism between vitamin a and pcbs in seal milk. | bioaccumulating pollutants such as polychlorinated biphenyls (pcbs) induce a range of adverse effects in mammals. vitamin a metabolism is prone to such pollutant disruption which may be particularly harmful for young animals. during lactation, maternal pcbs are transferred to the offspring through the milk. seal milk is very fatty and consequently contains large amounts of these persistent lipophilic contaminants. in the present study, we investigated the relationships between pcbs and vitamins ... | 2004 | 15145227 |
| metabolic rates of captive grey seals during voluntary diving. | the energetic cost of diving in marine mammals is a difficult value to derive given the problems of assessing metabolic rate for an animal at sea. nevertheless, it is fundamental to our understanding of the foraging strategies of air-breathers exploiting underwater food sources. we measured the metabolic rates of eight captive grey seals, voluntarily diving in a quasi-natural setting. oxygen consumption during post-dive surface periods was measured using open-flow respirometry, and dive behaviou ... | 2004 | 15073194 |
| contrasting changes of sensitivity by lymphocytes and neutrophils to mercury in developing grey seals. | mercury is the principal metal contaminant in the st lawrence estuary. it impairs humoral, cellular and non-specific immune responses in many species. since the immune system of juvenile seals is immature, it should react differently to the effects of contamination compared to that of mature animals. phagocytosis and lymphoblastic transformation responses have been evaluated in the peripheral blood leukocytes of eight juvenile grey seals at different intervals of time over 11 weeks. dose-respons ... | 2003 | 12798369 |
| the immunocompetence handicap hypothesis in two sexually dimorphic pinniped species--is there a sex difference in immunity during early development? | the 'immunocompetence handicap hypothesis' predicts that highly sexually dimorphic and polygynous species will exhibit sex differences in immunity. we tested this hypothesis in southern elephant and grey seals during their early development by measuring the following parameters: leucocyte counts, serum igg levels, erythrocyte sedimentation rate and haematocrit. we failed to find any differences due to sex as assessed by the parameters investigated. animals were sampled longitudinally during thei ... | 2006 | 12697319 |
| patterns of colonization in a metapopulation of grey seals. | the colonization of a new habitat is a fundamental process in metapopulation biology, but it is difficult to study. the emigration of colonists from established populations might be induced by resource competition owing to high local population density. migration distances are also important because they determine the frequency and scale of recolonization and hence the spatial scale of the metapopulation. traditionally, these factors have been investigated with demographic approaches that are la ... | 2002 | 11919630 |
| distribution of cytochrome p4501a (cyp1a) in the tissues of baltic ringed and grey seals. | information about the expression of cyp1a in wildlife species is essential for understanding the impact of organochlorine exposure on the health status of an exposed population. therefore, we aimed at characterising a putative cyp1a enzyme expression in both hepatic and extrahepatic tissues of ringed and grey seals from the baltic sea and from less polluted waters. the cellular localisation of cyp1a was identified using a monoclonal antibody against scup p4501a1 (mab 1-12-3). immunohistochemical ... | 2001 | 11488512 |
| polychlorinated diphenyl ethers, dibenzo-p-dioxins, dibenzofurans and biphenyls in seals and sediment from the gulf of finland. | polychlorinated diphenyl ethers (pcdes), 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (pcdds) and dibenzofurans (pcdfs), and polychlorinated biphenyls (pcbs) were analyzed in seals from the gulf of finland and in sediments from the gulf of finland and near gotland. the sediments included one surface core from both sampling sites. the seal material consisted of 14 ringed seals and 6 grey seals that all were found dead and examined for pathology. the main aims were to scrutinize levels an ... | 1997 | 9308160 |
| organochlorine residues in two seal species from western iceland. | harbour seals and grey seals from faxaflói (western iceland) were analyzed for contamination with organochlorines (hcb, pcbs, p,p'-ddt,p,p'-dde, chlordanes and the enantiomers of alpha-hch). although the values strongly varied, both harbour seals and grey seals on averaged showed comparable levels of pcbs, p,p'-ddt, p,p'-dde and alpha-hch, as well as chlordanes (sigma cd). differences were measured in the hcb content of the seal species. the hcb/alpha-hch ratio in harbour seals was < 1 and in gr ... | 1995 | 7481739 |
| identification, characterisation, and measurement of immunoglobulin concentrations in grey (haliocherus grypus) and common (phoca vitulina) seals. | concentrations of macroglobulin, total gammaglobulin, and a gammaglobulin subclass were measured in grey and common seals. in pups, immunoglobulin m (igm) was found to rise rapidly, concentrations reaching adult values by approximately 14 days postpartum. total igg concentrations increased more slowly, only approaching 50% of juvenile and adult male values by 30 days after birth. concentrations of the igg subclass did not change significantly postpartum. total igg concentrations measured in adul ... | 2006 | 7535255 |
| skin lesions on grey seals. | | 1991 | 1659023 |
| pathological findings indicative of distemper in european seals. | the first recorded cases of the recent epizootic were harbour seals observed at the danish island of anholt, 12 april 1988. the disease then spread throughout the sea waters of north-western europe. the total mortality in europe up to november 1988, was estimated to be at least 17,000 seals. the mortality rate in danish-swedish waters was about 60%. autopsies including sampling for histology of most organs were performed on 37 harbour seals and 12 grey seals, collected mainly at the swedish west ... | 1990 | 2402876 |
| pollution-associated uterine lesions in grey seals from the liverpool bay area of the irish sea. | | 1989 | 2510393 |
| [post-mortem findings in seals which died in nature (author's transl)]. | the findings in seals submitted to the research institute for nature management, arnhem, for post-mortem examination during the period from 1960 to 1981 are reviewed with reference to three tables. a striking feature was the large proportion (55 per cent) of young seals, well over 38 percent of which died in the first two months of life. there also was a large proportion of young seals and yearlings with parasitic infections, which would appear to suggest that it is difficult for the young anima ... | 1982 | 7101258 |
| red cell and serum protein systems of grey seals and habour seals. | | 1975 | 1122728 |
| blood values in young gray seals. | | 1971 | 5571825 |
| breeding behavior in a colony of western atlantic gray seals. | | 1967 | 6073489 |
| 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 |
| could biotransport be an important pathway in the transfer of phenol derivatives into the coastal zone and aquatic system of the southern baltic? | bird guano and the faeces of marine mammals appear to be a significant yet undisclosed biotransporter of endocrine disrupting compounds in the marine environment. the authors determined the concentration of bisphenol a (bpa), 4-tert-octylphenol (4-t-op) and 4-nonylphenol (4-np) removed from birds and seals in their droppings into the coastal zone of the gulf of gdansk (southern baltic sea).the research was carried out on samples of bird guano collected during the breeding season and after in 201 ... | 2020 | 32443210 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| after the bite: bacterial transmission from grey seals (halichoerus grypus) to harbour porpoises (phocoena phocoena). | recent population growth of the harbour porpoise (phocoena phocoena), grey seal (halichoerus grypus) and common seal (phoca vitulina) in the north sea has increased potential interaction between these species. grey seals are known to attack harbour porpoises. some harbour porpoises survive initially, but succumb eventually, often showing severely infected skin lesions. bacteria transferred from the grey seal oral cavity may be involved in these infections and eventual death of the animal. in hum ... | 2020 | 32537205 |
| comparison of streptococcus halichoeri isolates from canine and fur animal infections: biochemical patterns, molecular characteristics and genetic relatedness. | streptococcus halichoeri infections have been reported in grey seals, a european badger, a stellar sea lion and humans, but its presence in companion and fur animals is unknown. since 2010, s. halichoeri-like bacteria (shl) have been isolated from fur animals and dogs in finland. our aim was to retrospectively investigate laboratory records for shl from canine and fur animal infections, characterize the isolates and compare their genetic relatedness in relation to three reference strains: ccug 4 ... | 2020 | 32493395 |
| detection of h3n8 influenza a virus with multiple mammalian-adaptive mutations in a rescued grey seal (halichoerus grypus) pup. | avian influenza a viruses (iavs) in different species of seals display a spectrum of pathogenicity, from sub-clinical infection to mass mortality events. here we present an investigation of avian iav infection in a 3- to 4-month-old grey seal (halichoerus grypus) pup, rescued from st michael's mount, cornwall in 2017. the pup underwent medical treatment but died after two weeks; post-mortem examination and histology indicated sepsis as the cause of death. iav np antigen was detected by immunohis ... | 2020 | 32211197 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| exploring causal components of plasticity in grey seal birthdates: effects of intrinsic traits, demography, and climate. | change in breeding phenology is often a response to environmental forcing, but less is known of the mechanism underlying such changes and their fitness consequences. here, we report on changes in the breeding phenology from a 27-year longitudinal study (1991-2017) of individually marked, known-aged grey seals (halichoerus grypus) on sable island, nova scotia, canada. we used generalized linear mixed models and a 3-step process to develop a model that includes interactions between intrinsic and e ... | 2020 | 33144980 |
| foraging behaviour of a continental shelf marine predator, the grey seal (halichoerus grypus), is associated with in situ, subsurface oceanographic conditions. | the heterogeneous oceanographic conditions of continental shelf ecosystems result in a three-dimensionally patchy distribution of prey available to upper-trophic level predators. the association of bio-physical conditions with movement patterns of large marine predators has been demonstrated in diverse taxa. however, obtaining subsurface data that are spatio-temporally relevant to the decisions made by benthically-foraging species can be challenging. | 2020 | 33093960 |
| life cycle bioenergetics of the gray seal (halichoerus grypus) in the baltic sea: population response to environmental stress. | wildlife population dynamics are shaped by multiple natural and anthropogenic factors, including predation, competition, stressful life history events, and external environmental stressors such as diseases and pollution. marine mammals such as gray seals rely on extensive blubber layers for insulation and energy storage, making this tissue critical for survival and reproduction. this lipid rich blubber layer also accumulates hazardous fat soluble pollutants, such as polychlorinated biphenyls (pc ... | 2020 | 33038624 |
| assessing harbour porpoise carcasses potentially subjected to grey seal predation. | as a follow-up on the data presented for seals, we herein report and discuss outcomes resulting from a retrospective evaluation of harbour porpoise stranding and necropsy data from schleswig-holstein, germany (n = 4463) to enable an objective evaluation of potential ecological effects of grey seal predation on porpoises. results are compared to a recent case of definite grey seal predation as well as to reports from other countries. porpoise carcasses potentially subject to grey seal predation s ... | 2020 | 33004890 |
| liver histopathology of baltic grey seals (halichoerus grypus) over three decades. | the liver plays an important role in the metabolism and elimination of endogenic and exogenic lipid-soluble compounds. multiple studies have shown that polychlorinated biphenyls (pcb) and dichlorodiphenyl trichloroethane (ddt) lead to morphological changes in liver cells. the aim of the present study was therefore to analyse liver changes over time in baltic grey seals (halichoerus grypus) and to correlate these with historical pcb and ddt contaminations. a total of 191 liver samples were collec ... | 2020 | 32937284 |
| alimentary exposure and elimination routes of rare earth elements (ree) in marine mammals from the baltic sea and antarctic coast. | marine mammals found at the top of the trophic pyramid are excellent bioindicators of pollutants in the marine environment, the concentrations of which increase along with the trophic level of the organism. as these animals are usually protected species, their contamination has to be assessed non-invasively by analysing excrement and epidermal structures such as fur or claws. the present study involved testing the excrement and fur of the grey seal (halichoerus grypus) from the southern baltic c ... | 2020 | 32916487 |
| energetic limits: defining the bounds and trade-offs of successful energy management in a capital breeder. | judicious management of energy can be invaluable for animal survival and reproductive success. capital breeding mammals typically transfer energy to their young at extremely high rates while undergoing prolonged fasting, making lactation a tremendously energy demanding period. effective management of the competing demands of the mother's energy needs and those of her offspring is presumably fundamental to maximizing lifetime reproductive success. how does the mother maximize her chances of succe ... | 2020 | 32895978 |
| predicting the exposure of diving grey seals to shipping noise. | there is high spatial overlap between grey seals and shipping traffic, and the functional hearing range of grey seals indicates sensitivity to underwater noise emitted by ships. however, there is still very little data regarding the exposure of grey seals to shipping noise, constraining effective policy decisions. particularly, there are few predictions that consider the at-sea movement of seals. consequently, this study aimed to predict the exposure of adult grey seals and pups to shipping nois ... | 2020 | 32873039 |
| fatty acid composition in blubber, liver, and muscle of marine mammals in the southern baltic sea. | to date, only limited results on the fatty composition in different tissues of the top predators in the baltic sea are available. in the current study, tissue samples of blubber, skeletal muscle, and liver from 8 harbour porpoise (phocoena phocoena) and 17 grey seals (halichoerus grypus) in the baltic sea off mecklenburg-western pomerania were included in the investigation. while the total fatty acid content in liver and blubber tissue revealed no differences between both species, the total fatt ... | 2020 | 32859039 |
| organohalogen compounds of emerging concern in baltic sea biota: levels, biomagnification potential and comparisons with legacy contaminants. | while new chemicals have replaced major toxic legacy contaminants such as polychlorinated biphenyls (pcbs) and dichlorodiphenyltrichloroethane (ddt), knowledge of their current levels and biomagnification potential in baltic sea biota is lacking. therefore, a suite of chemicals of emerging concern, including organophosphate esters (opes), short-chain, medium-chain and long-chain chlorinated paraffins (sccps, mccps, lccps), halogenated flame retardants (hfrs), and per- and polyfluoroalkyl substan ... | 2020 | 32835922 |
| male grey seal commits fatal sexual interaction with adult female harbour seals in the german wadden sea. | males of several seal species are known to show aggressive copulating behaviour, which can lead to injuries to or suffocation of females. in the north sea, grey seal predation on harbour seals including sexual harassment is documented and represents violent interspecific interaction. in this case series, we report pathological and molecular/genetic findings of 11 adult female harbour seals which were found dead in schleswig-holstein, germany, within 41 days. several organs of all animals showed ... | 2020 | 32792537 |
| census data aggregation decisions can affect population-level inference in heterogeneous populations. | conservation and population management decisions often rely on population models parameterized using census data. however, the sampling regime, precision, sample size, and methods used to collect census data are usually heterogeneous in time and space. decisions about how to derive population-wide estimates from this patchwork of data are complicated and may bias estimated population dynamics, with important implications for subsequent management decisions.here, we explore the impact of site sel ... | 2020 | 32760543 |
| contracaecum osculatum (sensu lato) infection of gadus morhua in the baltic sea: inter- and intraspecific interactions. | the subpopulation of atlantic cod, gadus morhua, in the eastern part of the baltic sea has experienced a significant increase in infections with anisakid nematode larvae of the species contracaecum osculatum sensu lato (s.l.) since the year 2000. the life cycle of the parasite includes seals and especially the grey seal, halichoerus grypus, as final hosts, carrying the adult nematodes in the stomach, crustaceans (copepods, amphipods) as first intermediate hosts and various fish species (clupeids ... | 2020 | 32681931 |
| nematode parasites in baltic sea mammals, grey seal (halichoerus grypus (fabricius, 1791)) and harbour porpoise (phocoena phocoena (l.)), from the german coast. | endoparasitic nematodes of six harbour porpoises phocoena phocoena and four grey seals halichoerus grypus, stranded at the eastern coast of the baltic sea in germany in winter 2019, were analysed in order to identify nematode parasites and to compare with recent studies from the same area. | 2020 | 32642980 |
| reactive stress-coping styles show more variable reproductive expenditure and fitness outcomes. | stress-coping styles dictate how individuals react to stimuli and can be measured by the integrative physiological parameter of resting heart-rate variability (hrv); low resting hrv indicating proactive coping styles, while high resting hrv typifies reactive individuals. over 5 successive breeding seasons we measured resting hrv of 57 lactating grey seals. mothers showed consistent individual differences in resting hrv across years. we asked whether proactive and reactive mothers differed in the ... | 2020 | 32533041 |
| baltic cod endohelminths reflect recent ecological changes. | we suggest helminthological investigations of cod as a supplement to traditional biological and hydrographical methods for elucidation of ecological changes in the baltic sea. it is under discussion if oxygen deficit or seal abundance should explain the present critical situation of baltic cod. a comparative investigation of endoparasitic helminths in baltic cod (gadus morhua), captured in the same marine habitat with an interval of 35 years (1983/2018) recorded 11 species of helminths comprisin ... | 2020 | 32410718 |
| stockpiling by pups and self-sacrifice by their fasting mothers observed in birth to weaning serum metabolomes of atlantic grey seals. | during the uniquely short lactations of true seals, pups acquire a greater proportion of maternal body resources, at a greater rate, than in any other group of mammals. mothers in many species enter a period of anorexia but must preserve sufficient reserves to fuel hunting and thermoregulation for return to cold seas. moreover, pups may undergo a period of development after weaning during which they have no maternal care or nutrition. this nutritionally closed system presents a potentially extre ... | 2020 | 32366923 |
| health effects from contaminant exposure in baltic sea birds and marine mammals: a review. | here we review contaminant exposure and related health effects in six selected baltic key species. sentinel species included are common eider, white-tailed eagle, harbour porpoise, harbour seal, ringed seal and grey seal. the review represents the first attempt of summarizing available information and baseline data for these biomonitoring key species exposed to industrial hazardous substances focusing on anthropogenic persistent organic pollutants (pops). there was only limited information avail ... | 2020 | 32311628 |
| intestinal displacements in older harbour and grey seals. | intestinal displacements including volvulus, torsion and invagination have been reported in various terrestrial and marine mammals. we conducted pathological investigations on 157 seals that had either stranded on the coasts of the north or baltic sea between 1996 and 2015 (115 harbour seals, >19 mo old; 21 grey seals, >13 mo old) or died while in human care (18 harbour seals, >19 mo old; 3 grey seals, >13 mo old). intestinal displacements were found in 23% of the examined free-living harbour se ... | 2020 | 32213669 |
| serum biochemical and hematologic reference intervals for weanling northwest atlantic gray seals (halichoerus grypus). | baseline health parameters are limited in the primary literature for gray seals (halichoerus grypus) in the northwest atlantic. accurate normal physiologic reference ranges for both species and specific geographic populations are vital tools for assessing the health of individuals and understanding the health of the entire population. this study developed comprehensive reference intervals for biochemical and hematologic parameters of recently weaned gray seal pups on cape cod, massachusetts from ... | 2020 | 32212568 |
| streptococcus halichoeri: comparative genomics of an emerging pathogen. | streptococcus halichoeri is an emerging pathogen with a variety of host species and zoonotic potential. it has been isolated from grey seals and other marine mammals as well as from human infections. beginning in 2010, two concurrent epidemics were identified in finland, in fur animals and domestic dogs, respectively. the fur animals suffered from a new disease fur animal epidemic necrotic pyoderma (fenp) and the dogs presented with ear infections with poor treatment response. s. halichoeri was ... | 2020 | 32149071 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |