Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| 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 |