Stranding collections indicate broad-scale connectivity across the range of a pelagic marine predator, the Atlantic white-sided dolphin (Lagenorhynchus acutus)

Understanding the extent of population genetic connectivity in highly mobile marine species is vital for delineating management units. However, obtaining samples for generating genetic data is challenging for species inhabiting inaccessible pelagic waters. As a result, management strategies do not always align with underlying population biology. Marine strandings provide an accessible and cost-effective sample source for research on elusive cetaceans and can be used collaboratively among stranding networks to generate ecosystem-wide population genetic assessments. Here, we used samples collected from strandings and free-ranging individuals across the North Atlantic to investigate population structure, genetic diversity, and individual relatedness in the Atlantic white-sided dolphin (AWSD; Lagenorhynchus acutus), a widely distributed marine predator. Mitochondrial DNA sequences and nuclear DNA single-nucleotide polymorphisms showed a complete lack of population differentiation across the species’ range, implying an unusual pattern of strong connectivity. No differences in genetic diversity among geographic regions and weak within-group relatedness further support the existence of species-wide panmixia in AWSD. This study emphasises the value of long-term stranding collections for cetacean research and has important implications for AWSD conservation management

Examining Bergmann's rule in a cosmopolitan marine mammal, the bottlenose dolphin (Tursiops spp.)

No abstract available

Harbor Porpoise Deaths Associated with Erysipelothrix rhusiopathiae, the Netherlands, 2021

In August 2021, a large-scale mortality event affected harbor porpoises (Phocoena phocoena) in the Netherlands. Pathology and ancillary testing of 22 animals indicated that the most likely cause of death was Erysipelothrix rhusiopathiae infection. This zoonotic agent poses a health hazard for cetaceans and possibly for persons handling cetacean carcasses

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 from grey seals. We therefore conclude that these porpoises survived a grey seal predatory attack, with the bite lesions representing the subsequent portal of entry for bacteria to infect the animals causing abscesses in multiple tissues, and eventually death. We demonstrate that forensic microbiology provides a useful tool for linking a perpetrator to its victim. Moreover, N. animaloris should be added to the list of potential zoonotic bacteria following interactions with seals, as the finding of systemic transfer to the lungs and other tissues of the harbour porpoises may suggest a potential to do likewise in humans

Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea

Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England. The majority (n = 27) of the stranded animals were necropsied and/ or sampled, allowing for an international and comprehensive investigation into this mortality event. The animals were in fair to good nutritional condition and, aside from the pathologies caused by stranding, did not exhibit significant evidence of disease or trauma. Infectious agents were found, including various parasite species, several bacterial and fungal pathogens and a novel alphaherpesvirus. In nine of the sperm whales a variety of marine litter was found. However, none of these findings were considered to have been the primary cause of the stranding event. Potential anthropogenic and environmental factors that may have caused the sperm whales to enter the North Sea were assessed. Once sperm whales enter the North Sea and head south, the water becomes progressively shallower (<40 m), making this region a global hotspot for sperm whale strandings. We conclude that the reasons for sperm whales to enter the southern North Sea are the result of complex interactions of extrinsic environmental factors. As such, these large mortality events seldom have a single ultimate cause and it is only through multidisciplinary, collaborative approaches that potentially multifactorial large-scale stranding events can be effectively investigated

Dead useful; methods for quantifying baseline variability in stranding rates to improve the ecological value of the strandings record as a monitoring tool

The ecological value of the stranding record is often challenged due to the complexity in quantifying the biases associated with multiple components of the stranding process. There are biological, physical and social aspects that complicate the interpretation of stranding data particularly at a population level. We show how examination of baseline variability in the historical stranding record can provide useful insights into temporal trends and facilitate the detection of unusual variability in stranding rates. Seasonal variability was examined using harbour porpoise strandings between 1992 and 2014 on the east coast of Scotland. Generalized Additive Mixed modelling revealed a strong seasonal pattern, with numbers increasing from February towards a peak in April. Profiling seasonality this way facilitates detection of unusual variations in stranding frequencies and permits for any change in the incidence of strandings to be quantified by evaluation of the normalized model residuals. Consequently, this model can be used to identify unusual mortality events, and quantify the degree to which they deviate from baseline. With this study we demonstrate that a described baseline in strandings allows the detection of abnormalities at an early stage and can be used as a regional framework of reference for monitoring. This methodology provides means to quantify and partition the variability associated with strandings data and is a useful first step towards improving the stranding record as a management resource

SMASS/WDC Marine Forum 2020 Proceedings Report

Proceedings report for the 2020 SMASS/WDC Marine Forum. On the 29th of February, the Scottish Marine Animal Stranding Scheme (SMASS) and Whale and Dolphin Conservation (WDC) held the third Marine Forum at the Centre for Health Science in Inverness. A total of 150 people attended the one-day knowledge exchange event, which was packed with fascinating talks, workshops, discussions, and opportunities to network with a wide variety of experts actively involved with marine conservation

SMASS/WDC Marine Forum 2020 Proceedings Report

On the 29th of February, the Scottish Marine Animal Stranding Scheme (SMASS) and Whale and Dolphin Conservation (WDC) held the third Marine Forum at the Centre for Health Science in Inverness. A total of 150 people attended the one-day knowledge exchange event, which was packed with fascinating talks, workshops, discussions, and opportunities to network with a wide variety of experts actively involved with marine conservation. The marine forum was once again kindly funded by the SRUC Universities Innovations Fund. Bringing together representatives from a number of research organisations, higher education institutes, NGO’s and marine industries with policy makers and members of the public, this annual event provides a unique opportunity for the exchange of ideas between researchers, citizen scientists and other stakeholder groups concerned with the conservation of the marine environment

Dead useful; methods for quantifying baseline variability in stranding rates to improve the ecological value of the strandings record as a monitoring tool

The ecological value of the stranding record is often challenged due to the complexity in quantifying the biases associated with multiple components of the stranding process. There are biological, physical and social aspects that complicate the interpretation of stranding data particularly at a population level. We show how examination of baseline variability in the historical stranding record can provide useful insights into temporal trends and facilitate the detection of unusual variability in stranding rates. Seasonal variability was examined using harbour porpoise strandings between 1992 and 2014 on the east coast of Scotland. Generalized Additive Mixed modelling revealed a strong seasonal pattern, with numbers increasing from February towards a peak in April. Profiling seasonality this way facilitates detection of unusual variations in stranding frequencies and permits for any change in the incidence of strandings to be quantified by evaluation of the normalized model residuals. Consequently, this model can be used to identify unusual mortality events, and quantify the degree to which they deviate from baseline. With this study we demonstrate that a described baseline in strandings allows the detection of abnormalities at an early stage and can be used as a regional framework of reference for monitoring. This methodology provides means to quantify and partition the variability associated with strandings data and is a useful first step towards improving the stranding record as a management resource