Fatal systemic bacterial infections in two harbour porpoises (Phocoena phocoena) secondary to bite wounds from grey seals (Halichoerus grypus).

Mycoplasma phocicerebrale, the causative agent of seal ('speck') finger, a zoonotic disease, is a common commensal in the oral cavity of various seal species. Historically associated with seal hunters, it remains a significant risk for those handling or rehabilitating marine mammals. While primarily known for causing severe cellulitis in humans, M.

Intravascular central nervous system T-cell lymphoma in a common dolphin (Delphinus delphis) with cerebral infarction.

Lymphoid and haematopoietic neoplasms are rare in cetaceans. This report describes intravascular lymphoma in an adult common dolphin that presented with neurological signs prior to stranding. Intravascular lymphoma is a rare neoplasm previously recorded in humans, dogs, a cat and a horse.

Emaciated enigma: Decline in body conditions of common dolphins in the Celtic Seas ecoregion.

Monitoring the nutritional health of cetaceans has become increasingly important in a changing environment, where multiple stressors impact animals. Particularly for those species that require consumption of energy-dense prey, such as the common dolphin. Thus far, no uniform measure for monitoring body condition has been recommended across cetaceans, and species-specific measures may need to be developed if employed as a population condition indicator under Descriptor 1 of the Marine Strategy Framework Directive.

Network analysis to reveal the most commonly detected compounds in predator-prey pairs in freshwater and marine mammals and fish in Europe.

Marine and freshwater mammalian predators and fish samples, retrieved from environmental specimen banks (ESBs), natural history museum (NHMs) and other scientific collections, were analysed by LIFE APEX partners for a wide range of legacy and emerging contaminants (2545 in total). Network analysis was used to visualize the chemical occurrence data and reveal the predominant chemical mixtures for the freshwater and marine environments. For this purpose, a web tool was created to explore these chemical mixtures in predator-prey pairs.

Toxic arsenolipids bioaccumulate in the developing brain of pilot whales.

Arsenic-containing hydrocarbons (AsHC), a subclass of arsenolipids (AsL), have been proven to exert neuro- and cytotoxic effects in in-vitro and in-vivo studies and were shown to pass through biological barriers like the blood-brain barrier. However, there has been no connection as to the environmental relevance of these findings, meaning there is no study based on samples from free living animals that are exposed to these compounds. Here, we report the identification of two AsHC as well as 3 arsenosugar phospholipids (AsPL) in the brains of a pod of stranded long-finned pilot whales (Globicephala melas) as well as the absence of arsenobetaine (AsB) which is often found to be a dominant As species in fish.

Population genomics of the white-beaked dolphin (Lagenorhynchus albirostris): Implications for conservation amid climate-driven range shifts.

Climate change is rapidly affecting species distributions across the globe, particularly in the North Atlantic. For highly mobile and elusive cetaceans, the genetic data needed to understand population dynamics are often scarce. Cold-water obligate species such as the white-beaked dolphin (Lagenorhynchus albirostris) face pressures from habitat shifts due to rising sea surface temperatures in addition to other direct anthropogenic threats.

High resolution visualisation of tiemannite microparticles, essential in the detoxification process of mercury in marine mammals.

The North Sea is an ecologically rich habitat for marine wildlife which has also been impacted by industrial developments and anthropogenic emissions of contaminants such as mercury. Marine mammals are particularly susceptible to mercury exposure, due to their trophic position, long lifespan, and dependence on (increasingly contaminated) aquatic prey species. To mitigate impact, marine mammals can detoxify methylmercury by binding it to selenium-containing biomolecules, creating insoluble mercury selenide granules.

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.

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.

The concentration and biomagnification of PCBs and PBDEs across four trophic levels in a marine food web.

Contracting Parties to the OSPAR Convention for the Protection of the Maine Environment of the North-East Atlantic are required to undertake monitoring and assessment of both inorganic and organic contaminants. There is a requirement to assess contaminants across different trophic levels on an ecosystem-specific basis. However, this is currently constrained by the availability of relevant samples to cover the full range of trophic levels.

Development of Mercury Analysis by NanoSIMS for the Localization of Mercury-Selenium Particles in Whale Liver.

Nanoscale secondary ion mass spectrometry (NanoSIMS) is a dynamic SIMS technique, which offers high spatial resolution allowing the mapping of chemical elements at the nanometer scale combined with high sensitivity. However, SIMS for mercury analysis is a challenging issue due to the low secondary ion yield and has never been done on NanoSIMS. The introduction of an rf plasma oxygen primary ion source on NanoSIMS enabled higher lateral resolution and higher sensitivity for electropositive elements such as most metals.

Runs of homozygosity in killer whale genomes provide a global record of demographic histories.

Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale (Orcinus orca) demographic history is reflected in genome-wide heterozygosity and ROH length distributions, using a global data set of 26 genomes representative of geographic and ecotypic variation in this species, and two F1 admixed individuals with Pacific-Atlantic parentage.

First confirmed reports of the isolation of Brucella ceti from a Risso's dolphin Grampus griseus and a killer whale Orcinus orca.

Brucella ceti has been recovered from a number species of cetaceans worldwide over the last 25 yr. Here we report, for the first time, the recovery of B. ceti from a Risso's dolphin Grampus griseus and a killer whale Orcinus orca.

Meningoencephalitis in a common minke whale Balaenoptera acutorostrata associated with Brucella pinnipedialis and gamma-herpesvirus infection.

Fatal marine Brucella infections with histologic lesions specific to the central nervous system (CNS), known as neurobrucellosis, have been described in 5 species of odontocete cetaceans in the UK: striped dolphins Stenella coeruleoalba, Atlantic white-sided dolphins Lagenorhynchus acutus, short-beaked common dolphins Delphinus delphis, long-finned pilot whale Globicephala melas and Sowerby's beaked whale Mesoplodon bidens. To date, these CNS lesions have only been associated with Brucella ceti ST26 and not with B. pinnipedialis, which is rarely isolated from cetaceans and, although commonly found in various seal species, has never been associated with any pathology.

Novel Dermatitis and Relative Viral Nucleic Acid Tissue Loads in a Fin Whale (Balaenoptera physalus) with Systemic Cetacean Morbillivirus Infection.

Cetacean morbilliviruses (CeMVs) are significant causes of mortality in many cetacean species in epizootics and smaller outbreaks. Despite the prominence of skin lesions in seals and terrestrial animals, including humans, affected by other morbilliviruses, they have not been reported in CeMV-infected cetaceans. Here we report CeMV-associated skin lesions in a fin whale (Balaenoptera physalus) with subacute, systemic CeMV infection that live-stranded in Scotland, UK.

Neurobrucellosis due to Brucella ceti ST26 in Three Sowerby's Beaked Whales (Mesoplodon bidens).

Fatal meningoencephalitis due to Brucella ceti infection has been described in striped dolphins (Stenella coeruleoalba), Atlantic white-sided dolphins (Lagenorhynchus acutus), short-beaked common dolphins (Delphinus delphis) and long-finned pilot whales (Globicephala melas), which are all within the family Delphinidae. We report B. ceti-associated neurobrucellosis in three juvenile male Sowerby's beaked whales (Mesoplodon bidens) that all had typical lesions of lymphocytic meningoencephalitis, which increased in severity from rostral to caudal regions of the brain.

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.

Intrasarcoplasmic Polyglucosan Inclusions in Heart and Skeletal Muscles of Long-Finned Pilot Whales (Globicephala melas) may be Age-Related.

Polysaccharide storage myopathies have been described in several animal species and are characterized by periodic acid-Schiff (PAS)-positive, diastase-resistant intrasarcoplasmic inclusions in myocytes. Skeletal and cardiac muscle samples from a subset of a single pod of stranded long-finned pilot whales (Globicephala melas) were evaluated by light and transmission electron microscopy. Twelve individuals demonstrated sporadic basophilic packets of PAS-positive, diastase-resistant complex polysaccharide material, either centrally or peripherally, in skeletal and cardiac myocytes.

Campylobacter pinnipediorum subsp. caledonicus and C. pinnipediorum subsp. pinnipediorum recovered from abscesses in pinnipeds.

Campylobacter pinnipediorum was described recently for isolates recovered from pinnipeds. The novel species was further split into 2 subspecies based on host and geography, with C. pinnipediorum subsp.

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.