Search

Cetacean surveys in the Cape Verde Islands and the use of cookiecutter shark bite lesions as a population marker for fin whales. The skin condition of cetaceans, including scars, scratches, and injuries, can tell us a lot about the exposure to natural and anthropogenic impacts on individuals or populations (Baker, 1992; Herr et al., [24]; Kiszka et al., [30]; Van Bressem et al., [58]). In addition to the rarity of scars, the complete absence of blister-like skin lesions regularly observed in other large whale populations, e.g., New Zealand blue whales, I Balaenoptera musculus i (Barlow et al., [6]) and blue, fin and sperm whales, ( I Physeter macrocephalus i ) in the Gulf of California (Martinez-Levasseur et al., [38]) is noteworthy. [Extracted from the article]

In July 2012, a ship-board double-platform line-transect survey was conducted to assess harbour porpoise (Phocoena phocoena) abundance in the Kattegat, Belt Seas and the Western Baltic. A total of 826 km of track lines were surveyed between the 2nd and 21st of July 2012, and 169 observations were made by the primary observers, comprising a total of 230 porpoises. Fifty-seven observations were identified as duplicate sightings observed by both tracker and primary observers and were used to correct for availability and perception bias of the primary detections. Using Mark-Recapture Distance Sampling analysis, we produced a model using the half-normal key function, including sightability as the only covariate to estimate the density and abundance of harbour porpoise within the 51,511 [km.sup.2] survey area. Estimated detection probability on the transect line, known as g(0), was at 0.571 (±0.074; CV = 0.130). Using a point independence model of the detection function, the abundance of harbour porpoises within the survey area was estimated at 40,475 animals (95% CI 25,614-65,041, CV = 0.235) with an associated density of 0.786 animals [km.sup.-2] (95% CI 0.498-1.242, CV = 0.235) and an average group size of 1.488 animals. These results reflect densities obtained during the SCANS surveys in 1994 and 2005, indicating no significant population trend in the area. However, it should be noted that the survey area covers more than one population and that results are therefore not necessarily reflecting local population trends. Until proper population borders are obtained, the abundance estimate provides baseline data for future monitoring and is an important input to the assessment of the conservation status of harbour porpoises in the area., Introduction At least three genetically and morphologically distinct populations of harbour porpoises (Phocoena phocoena) have been identified in the waters between the eastern North Sea and the Baltic Sea: (1) [...]

During the RV Polarstern PS 89 (ANT-XXX/2) expedition from Cape Town to Atka Bay and back, 20 sightings of 26 individual blue whales (Balaenoptera musculus) were recorded in Antarctic waters west of the Greenwich Meridian between 16-20 January 2015. These observations suggest a more westerly extension of a reported hot spot between the Greenwich Meridian and 20°E. [ABSTRACT FROM AUTHOR]

This article explores the legal regime of the protection of marine species and habitats within European waters by taking the protection of harbour porpoises in the German territorial sea and exclusive economic zone as an example. The analysis is based on a scientific assessment of the occurrence of and the anthropogenic impacts on harbour porpoises in the North Sea. The relationship between the protection of marine species within the European Union (EU) on the one hand and the Common Fisheries Policy of the EU on the other constitutes a classic example of a user-environment conflict. The article explores how such conflicts ought to be solved under the pertinent legal rules. [ABSTRACT FROM AUTHOR]

This comment presents acoustic and visual data showing deep seafloor depression chains similar to those reported in Marsh et al. ( R. Soc. open sci. 5: 180286), though from a different deep-sea setting. Marsh et al. present data collected during cruise JC120 from polymetallic nodule rich sites within the Clarion-Clipperton Fracture Zone (CCFZ), at water depths of between 3999 and 4258 m. Within this comment, we present data collected with equivalent acoustic and imaging devices on-board the RV Sonne (SO261-March/April 2018) from the Atacama Trench, approximately 4000 m depth, which shows comparable depression chains in the seafloor. In contrast with the CCFZ observations, our study area was wholly free of polymetallic nodules, an observation therefore weakening the 'ballast collection' by deep-sea diving mammals formation hypothesis discussed in their paper . We support their alternate hypothesis that if these features are indeed generated by deep-diving megafauna, then they are more likely the resultant traces of infauna feeding or marks made during opportunistic capture of benthic fish/cephalopods. We observed these potential prey fauna with lander and towed camera systems during the cruise, with example images of these presented here. Both the SO261 and JC120 cruises employed high-resolution sidescan systems at deployment altitudes seldom used routinely until the last few years during scientific deep-sea surveys. Given that both cruises found these depression chains in contrasting physical regions of the East Pacific, they may have a more ubiquitous distribution than at just these sites. Thus, the impacts of cetacean foraging behaviour on deep seafloor communities, and the potential relevance of these prey sources to deep-diving species, should be considered., Competing Interests: We have no competing interests.

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., Competing Interests: The authors have declared that no competing interests exist.

30 sperm whales (Physeter macrocephalus) stranded along the coasts of the North Sea between January and February 2016. The gastro-intestinal tracts of 22 of the carcasses were investigated. Marine debris including netting, ropes, foils, packaging material and a part of a car were found in nine of the 22 individuals. Here we provide details about the findings and consequences for the animals. While none of the items was responsible for the death of the animal, the findings demonstrate the high level of exposure to marine debris and associated risks for large predators, such as the sperm whale., (Copyright © 2016 Elsevier Ltd. All rights reserved.)