Search

Abstract: Thirty alternative flame retardant compounds and a suite of 17 brominated diphenyl ether (BDE) congeners were determined in the blubber of 21 harbour porpoises stranded or bycaught around UK coasts during 2008 using GC-MS/MS. Of the 30 compounds, 19 were not detected. Of the remaining 11 compounds, some fell below the lowest calibration level and so were recorded as less than values, but were certainly present in the blubber samples (examples include tetrabromo-p-xylene (TBX), tetrabromo-o-chlorotoluene (TBCT) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (TBP-DBPE). Concentrations were low, the highest concentration being only 35μgkg−1 wet weight. This contrasted with those of the BDEs, summed concentrations which ranged from 54.6 to 913μgkg−1 wet weight, although levels in porpoise blubber have been declining since 1998. Both Dechlorane Plus (DDC-CO) isomers were detected in some samples, suggesting either that this product has been used in the UK or that its presence may result from atmospheric transport from source regions. BDE183, a marker for the octa-mix PBDE product, was found at low concentrations (0.63 to 1.7μgkg−1 wet weight) and the four nona- and deca-BDE congeners were not detected in any sample. [Copyright &y& Elsevier]

Ecological indicators for monitoring strategies are expected to combine three major characteristics: ecological significance, statistical credibility, and cost-effectiveness. Strategies based on stranding networks rank highly in cost-effectiveness, but their ecological significance and statistical credibility are disputed. Our present goal is to improve the value of stranding data as population indicator as part of monitoring strategies by constructing the spatial and temporal null hypothesis for strandings. The null hypothesis is defined as: small cetacean distribution and mortality are uniform in space and constant in time. We used a drift model to map stranding probabilities and predict stranding patterns of cetacean carcasses under H0 across the North Sea, the Channel and the Bay of Biscay, for the period 1990–2009. As the most common cetacean occurring in this area, we chose the harbour porpoise Phocoena phocoena for our modelling. The difference between these strandings expected under H0 and observed strandings is defined as the stranding anomaly. It constituted the stranding data series corrected for drift conditions. Seasonal decomposition of stranding anomaly suggested that drift conditions did not explain observed seasonal variations of porpoise strandings. Long-term stranding anomalies increased first in the southern North Sea, the Channel and Bay of Biscay coasts, and finally the eastern North Sea. The hypothesis of changes in porpoise distribution was consistent with local visual surveys, mostly SCANS surveys (1994 and 2005). This new indicator could be applied to cetacean populations across the world and more widely to marine megafauna. [ABSTRACT FROM AUTHOR]

Hearing is one of the major senses in whales and dolphins (cetaceans). This is the first report of severe mycotic otitis media in a cetacean, a juvenile female harbour porpoise ( Phocoena phocoena) from British waters that stranded alive. Gross examinations were followed by histological and microbiological investigations of the auditory apparatus. Both tympanic cavities and periotic sinuses displayed copious greenish-yellow purulent and caseous material . Severe fungal infestation by Aspergillus terreus was documented in the otic region but not in any other site of the body. Adjacent to the promontorium, massive accumulation of fibrinous secretion and infiltration of clusters of inflammatory cells were present. Newly formed cysts and vessels replaced the round window membrane location, reminiscent of granulation tissue. Inflammatory cells and a severe fibrin net were noted within the perilymphatic spaces of scala tympani and scala vestibuli, indicative of an acute fibrinous otitis. Inflammatory reactions have probably been caused by this fungal organism. The basilar membrane was solely covered by a simple cuboidal epithelium. Complete absence of sensory cells of the Organ of Corti characterised a further severe phenomenon, which possibly led to the animal's poor nutritional status and stranding. Potential portals of entry are being discussed. [ABSTRACT FROM AUTHOR]

Controls were placed on the production and use of the pentamix polybrominated diphenyl ether (PBDE) formulation within the European Union in 2004. In porpoises stranded or bycaught around the U.K., BDE congeners from this product predominate. Lipid-normalized concentrations of 9 (summed) BDE congeners in the blubber of 415 porpoises sampled during the period 1992-2008 have been investigated for possible time trends resulting from the regulatory action. Our analysis suggests that overall, median Σ9BDE concentrations peaked around 1998 and have since reduced by between 53.8% and 73.5% to 2008. Our best point estimate is that the reduction has been 67.6%. This decline was highly statistically significant (p < 0.001) and was not confounded by a range of other factors which were also considered (area, season, nutritional status, bycaught/stranded, and age class). [ABSTRACT FROM AUTHOR]

With global increases in anthropogenic pressures on wildlife populations comes a responsibility to manage them effectively. The assessment of marine ecosystem health is challenging and often relies on monitoring indicator species, such as cetaceans. Most cetaceans are however highly mobile and spend the majority of their time hidden from direct view, resulting in uncertainty on even the most basic population metrics. Here, we discuss the value of long-term and internationally combined stranding records as a valuable source of information on the demographic and mortality trends of the harbour porpoise (Phocoena phocoena) in the North Sea. We analysed stranding records (n = 16,181) from 1990 to 2017 and demonstrate a strong heterogeneous seasonal pattern of strandings throughout the North Sea, indicative of season-specific distribution or habitat use, and season-specific mortality. The annual incidence of strandings has increased since 1990, with a notable steeper rise particularly in the southern North Sea since 2005. A high density of neonatal strandings occurred specifically in the eastern North Sea, indicative of areas important for calving, and large numbers of juvenile males stranded in the southern parts, indicative of a population sink or reflecting higher male dispersion. These findings highlight the power of stranding records to detect potentially vulnerable population groups in time and space. This knowledge is vital for managers and can guide, for example, conservation measures such as the establishment of time-area-specific limits to potentially harmful human activities, aiming to reduce the number and intensity of human-wildlife conflicts. • International data synthesis to understand wildlife mortality and demographic trends • We demonstrate the value of long-term surveillance exemplified by stranding records. • Our analyses indicate potential vulnerable population groups in time and space. • Analytical methods allow establishment of robust baseline of spatiotemporal variation. • Results guide conservation measures aiming to reduce human-wildlife conflicts at sea. [ABSTRACT FROM AUTHOR]