Spatiotemporal Trends Spanning Three Decades Show Toxic Levels of Chemical Contaminants in Marine Mammals.

Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures.

Centralized red muscle in and the prevalence of regional endothermy in sharks.

The order Lamniformes contains charismatic species such as the white shark and extinct megatooth shark , and is of particular interest given their influence on marine ecosystems, and because some members exhibit regional endothermy. However, there remains significant debate surrounding the prevalence and evolutionary origin of regional endothermy in the order, and therefore the development of phenomena such as gigantism and filter-feeding in sharks generally. Here we show a basal lamniform shark, the smalltooth sand tiger shark , has centralized skeletal red muscle and a thick compact-walled ventricle; anatomical features generally consistent with regionally endothermy.

An investigation into the effects of climate change on baleen whale distribution in the British Isles.

Climate change is predicted to impact the distribution of many marine species. In the North-East Atlantic and elsewhere in the world, studies indicate that climate change is leading to poleward shifts in cetacean distribution. Here, strandings data collected in the British Isles from 1990 to 2020 were used to assess whether there is evidence of a shift in baleen whale distribution.

Evaluation of a marine mammal status and trends contaminants indicator for European waters.

Marine mammals are vulnerable to the bioaccumulation, biomagnification and lactational transfer of specific types of pollutants, such as industrial polychlorinated biphenyls (PCBs), due to their long-life spans, feeding at a high trophic level and unique fat stores that can serve as depots for these lipophilic contaminants. Currently, European countries are developing indicators for monitoring pollutants in the marine environment and assessing the state of biodiversity, requirements under both Regional Seas Conventions and European legislation. As sentinel species for marine ecosystem and human health, marine mammals can be employed to assess bioaccumulated contaminants otherwise below current analytical detection limits in water and lower trophic level marine biota.

Somatic mutation rates scale with lifespan across mammals.

The rates and patterns of somatic mutation in normal tissues are largely unknown outside of humans. Comparative analyses can shed light on the diversity of mutagenesis across species, and on long-standing hypotheses about the evolution of somatic mutation rates and their role in cancer and ageing. Here we performed whole-genome sequencing of 208 intestinal crypts from 56 individuals to study the landscape of somatic mutation across 16 mammalian species.

Systemic Erysipelothrix rhusiopathiae in seven free-ranging delphinids stranded in England and Wales.

Microbiology records for 1127 cetaceans stranded on English and Welsh beaches and examined at the Institute of Zoology between 1990 and 2019 were reviewed to identify cases of Erysipelothrix rhusiopathiae, an uncommon but potentially fatal zoonotic pathogen. Once cases were identified, prevalence was calculated, corresponding postmortem reports were reviewed, common gross and histopathological findings were identified, and antibiotic susceptibilities were determined. Overall prevalence for E.

Novel Presentation of DMV-Associated Encephalitis in a Long-Finned Pilot Whale (Globicephala melas).

Cetacean morbillivirus (CeMV) is an important global cause of morbidity and mortality in cetacean populations, with four pathological presentations including non-suppurative encephalitis. We describe an unusual case of dolphin morbillivirus (DMV)-associated non-suppurative encephalitis in a long-finned pilot whale (Globicephala melas), in which the lesions were orientated on the periventricular white matter and comprised prominent multifocal syncytia formation in the absence of systemic lesions. DMV RNA was detected in brain tissue by qRT-PCR and immunohistochemistry for morbillivirus antigen yielded intense labelling of syncytia in periventricular sites, with sparse involvement of the deeper neuroparenchyma.

Polychlorinated biphenyls are associated with reduced testes weights in harbour porpoises (Phocoena phocoena).

Polychlorinated biphenyls (PCBs) are highly toxic and persistent aquatic pollutants that are known to bioaccumulate in a variety of marine mammals. They have been associated with reduced recruitment rates and population declines in multiple species. Evidence to date documents effects of PCB exposures on female reproduction, but few studies have investigated whether PCB exposure impacts male fertility.

Levels of Polychlorinated Biphenyls Are Still Associated with Toxic Effects in Harbor Porpoises () Despite Having Fallen below Proposed Toxicity Thresholds.

Polychlorinated biphenyls (PCBs) are toxic, persistent, and lipophilic chemical compounds that accumulate to high levels in harbor porpoises () and other cetaceans. It is important to monitor PCBs in wildlife, particularly in highly exposed populations to understand if concentrations are declining and how levels relate to toxicological thresholds and indices of health like infectious disease mortality. Here we show, using generalized additive models and tissue samples of 814 U.

Phylogenomic Resolution of the Cetacean Tree of Life Using Target Sequence Capture.

The evolution of cetaceans, from their early transition to an aquatic lifestyle to their subsequent diversification, has been the subject of numerous studies. However, although the higher-level relationships among cetacean families have been largely settled, several aspects of the systematics within these groups remain unresolved. Problematic clades include the oceanic dolphins (37 spp.

Reproductive Failure in UK Harbour Porpoises Phocoena phocoena: Legacy of Pollutant Exposure?

Reproductive failure in mammals due to exposure to polychlorinated biphenyls (PCBs) can occur either through endocrine disrupting effects or via immunosuppression and increased disease risk. To investigate further, full necropsies and determination of summed 25 polychlorinated biphenyls congeners (∑PCBs lipid weight) in blubber were undertaken on 329 UK-stranded female harbour porpoises (1990-2012). In sexually mature females, 25/127 (19.

Enhancer evolution across 20 mammalian species.

The mammalian radiation has corresponded with rapid changes in noncoding regions of the genome, but we lack a comprehensive understanding of regulatory evolution in mammals. Here, we track the evolution of promoters and enhancers active in liver across 20 mammalian species from six diverse orders by profiling genomic enrichment of H3K27 acetylation and H3K4 trimethylation. We report that rapid evolution of enhancers is a universal feature of mammalian genomes.

Helicobacter cetorum infection in striped dolphin (Stenella coeruleoalba), Atlantic white-sided dolphin (Lagenorhynchus acutus), and short-beaked common dolphin (Delphinus delphus) from the southwest coast of England.

Helicobacter infection in cetaceans was first reported from the US in 2000 when the isolation of a novel Helicobacter species was described from two Atlantic white-sided dolphins (Lagenorhynchus acutus). Since then, Helicobacter species have been demonstrated in cetaceans and pinnipeds from around the world. Since 1990, the Animal Health and Veterinary Laboratories Agency Polwhele, Truro, has been involved in the UK Cetacean Strandings Investigation Programme to establish the cause of death of cetacean species stranded along the coast of Cornwall, England.

Meningoencephalitis and arthritis associated with Brucella ceti in a short-beaked common dolphin (Delphinus delphis).

Brucella species infection in marine mammal species has been reported to have a global distribution. In 2007, the description of Brucella ceti was published and formally adopted for those isolates originating from cetaceans and pathologic lesions similar to those seen in terrestrial mammals infected with Brucella spp. have been associated with its isolation.

What caused the UK's largest common dolphin (Delphinus delphis) mass stranding event?

On 9 June 2008, the UK's largest mass stranding event (MSE) of short-beaked common dolphins (Delphinus delphis) occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury.

Using network theory to identify the causes of disease outbreaks of unknown origin.

The identification of undiagnosed disease outbreaks is critical for mobilizing efforts to prevent widespread transmission of novel virulent pathogens. Recent developments in online surveillance systems allow for the rapid communication of the earliest reports of emerging infectious diseases and tracking of their spread. The efficacy of these programs, however, is inhibited by the anecdotal nature of informal reporting and uncertainty of pathogen identity in the early stages of emergence.

Poxviral disease in red squirrels Sciurus vulgaris in the UK: spatial and temporal trends of an emerging threat.

The squirrel poxvirus (SQPV) is the probable mediator of apparent competition between the introduced invading gray squirrel (Sciurus carolinensis) and the red squirrel (Sciurus vulgaris) in the UK, and modeling studies have shown that this viral disease has had a significant impact on the decline of the red squirrel in the UK. However, given our limited understanding of the epidemiology of the disease, and more generally the effects of invasive species on parasite ecology, there is a need to investigate the transmission dynamics and the relative pathogenicity of the virus between species. We aimed to increase our knowledge of these processes through an empirical study in which we: (i) used pathological signs and transmission electron microscopy (TEM) to diagnose SQPV disease in red squirrels found dead during scanning surveillance between 1993 and 2005; (ii) detected antibody to SQPV using an enzyme-linked immunosorbent assay (ELISA) in the same animals; and (iii) mapped cases of the disease, and the gray squirrel distribution, using a geographical information system.

The risk of infection from polychlorinated biphenyl exposure in the harbor porpoise (Phocoena phocoena): a case-control approach.

The objective of this study was to determine whether the risk of mortality from infectious disease in harbor porpoise in U.K. waters increased with high exposure to polychlorinated biphenyls (PCBs), using a case-control study design.

Isolation and characterisation of main olfactory and vomeronasal receptor gene families from the Atlantic salmon (Salmo salar).

The Atlantic salmon (Salmo salar) has been widely used as a model species in studies of olfactory signal transduction and processing. Here we report the isolation and characterisation of salmon olfactory receptor (SOR) and salmon vomeronasal receptor (SVR) partial sequences from Atlantic salmon. Six groups of SOR sequences (SORA-F) and three groups of SVR sequences (SVRA-C) were identified.

Relationships between polychlorinated biphenyls and health status in harbor porpoises (Phocoena phocoena) stranded in the United Kingdom.

To investigate possible relationships between polychlorinated biphenyl (PCB) exposure and infectious disease mortality in harbor porpoises (Phocoena phocoena) in United Kingdom waters, summed blubber concentrations of 25 chlorobiphenyl congeners (sigma25CB) in healthy harbor porpoises that died of acute physical trauma (mainly by-catch; n = 175) were compared with sigma25CB values in animals that died of infectious disease (n = 82). The infectious disease group had significantly greater sigma25CB values (mean, 27.6 mg/kg lipid) than the physical trauma group (mean, 13.