[en] Highlights: • Floating marine DDFC were analysed in relation to cetacean abundances off Portugal. • Cetaceans are exposed to DDFC at different risk levels within the study area. • The highest concentration areas of DDFC and cetaceans did not overlap. • DDFC-cetacean interaction is more probable in the centre of the study area. Floating Dangerous Debris For Cetaceans (DDFC) and cetacean abundances were assessed by shipboard visual surveys off continental Portugal. Plastic litter (other than fishing gear) was the most abundant category, corresponding to 56.53% of the total recorded DDFC. Areas of DDFC and cetacean potential overlap suggest that cetaceans are generally exposed to DDFC at different risk levels within the study area. The highest concentration areas of DDFC and cetaceans did not overlap, whereas lower DDFC concentration areas (70% kernel probability contour) overlapped with 45% of the distribution area obtained for cetaceans. Future marine litter management measures (prevention or mitigation) should be focused on the predicted high DDFC-cetacean interaction risk area in the central region of the study. DDFC are representative of the overall floating litter distribution and future floating litter assessments could be based on DDFC categories alone.

[en] This study used field data of echeneid and ectoparasitic associations with free-swimming whale sharks (Rhincodon typus) and captured mako sharks (Isurus oxyrinchus) to test whether (1) echeneid presence was positively correlated with ectoparasitic presence; and (2) the number of ectoparasitic was negatively correlated with the number of echeneid fish. Data from whale and mako sharks do not support the first hypothesis whereas data from mako sharks yields support for the second hypothesis. The results indicate that echeneids do regulate the number of ectoparasitic on at least some host species, but these benefits may be contingent on the echeneid species.

[en] Pyrethroids (PYR) and UV filters (UVF) were investigated in tissues of paired mother-fetus dolphins from Brazilian coast in order to investigate the possibility of maternal transfer of these emerging contaminants. Comparison of PYR and UVF concentrations in maternal and fetal blubber revealed Franciscana transferred efficiently both contaminants to fetuses (F/M > 1) and Guiana dolphin transferred efficiently PYR to fetuses (F/M > 1) different than UVF (F/M < 1). PYR and UVF concentrations in fetuses were the highest-ever reported in biota (up to 6640 and 11,530 ng/g lw, respectively). Muscle was the organ with the highest PYR and UVF concentrations (p < 0.001), suggesting that these two classes of emerging contaminants may have more affinity for proteins than for lipids. The high PYR and UVF concentrations found in fetuses demonstrate these compounds are efficiently transferred through placenta. This study is the first to report maternal transfer of pyrethroids and UV filters in marine mammals. - Highlights: • First time maternal transfer of pyrethroids and UV filters in mammals was reported. • Pollutants in fetus tissues characterize their transplacental transfer. • Fetuses had pyrethroid and UV filter levels 10 times higher than their mothers. • Muscle was the organ presented with the highest concentrations of PYR and UVF. - Pyrethroids and UV filter concentrations in fetus and mother dolphin tissues demonstrated placenta and milk transfer in marine mammals.

[en] Highlights: • A climate vulnerability assessment was applied to cetaceans in Macaronesia • Very High to High vulnerability scores for 62% of species management units • Very High to Moderate certainty scores for 67% of units • High potential for climate-related responses for over 50% of units • Further research on trait-based approaches is needed to support decision-makers Over the last decades global warming has caused an increase in ocean temperature, acidification and oxygen loss which has led to changes in nutrient cycling and primary production affecting marine species at multiple trophic levels. While knowledge about the impacts of climate change in cetacean's species is still scarce, practitioners and policymakers need information about the species at risk to guide the implementation of conservation measures. To assess cetacean's vulnerability to climate change in the biogeographic region of Macaronesia, we adapted the Marine Mammal Climate Vulnerability Assessment (MMCVA) method and applied it to 21 species management units using an expert elicitation approach. Results showed that over half (62%) of the units assessed presented Very High (5 units) or High (8 units) vulnerability scores. Very High vulnerability scores were found in archipelago associated units of short-finned pilot whales (Globicephala macrorhynchus) and common bottlenose dolphins (Tursiops truncatus), namely in the Canary Islands and Madeira, as well as Risso's dolphins (Grampus griseus) in the Canary Islands. Overall, certainty scores ranged from Very High to Moderate for 67% of units. Over 50% of units showed a high potential for distribution, abundance and phenology changes as a response to climate change. With this study we target current and future information needs of conservation managers in the region, and guide research and monitoring efforts, while contributing to the improvement and validation of trait-based vulnerability approaches under a changing climate.

[en] On the Newfoundland (Canada) foraging ground, humpback whales (Megaptera novaeangliae (Borowski, 1781)) are found associated with a dominant forage fish species, capelin (Mallotus villosus (Müller, 1776)), that experienced a population collapse in the early 1990s and has not recovered. Our primary goal was to reconstruct dietary proportions of humpback whales on their summer foraging grounds off the northeast coast of Newfoundland during July–August 2016 and 2017 using a Bayesian stable isotope mixing model (MixSiar). Modelled dietary proportions were similar in both years, with capelin comprising ∼90% of the diet. However, both δ¹³C and δ¹⁵N in humpback whale skin differed significantly between years, resulting in minimal isotopic niche overlap (9%). Lipid-extracted and nonlipid-extracted skin samples were used to develop a lipid normalization equation: Δ¹³C = –3.184 + 1.011(C:N). Overall, findings suggest that capelin is the primary prey type of humpback whales in coastal Newfoundland, despite the continued collapsed state of the capelin population. Findings also reiterate that dietary reconstruction from stable isotope analysis of cetacean skin can be misinterpreted without concurrently sampled isotopic ratios of potential prey types. (author)

[en] In the Arctic, warming and concomitant reductions in sea ice will affect the underwater soundscape, with the greatest changes likely being linked to anthropogenic activities. In this study, an acoustic recorder deployed on an oceanographic mooring in western Fram Strait documented the soundscape of this area, which is important habitat for the Critically Endangered Spitsbergen bowhead whale population. The soundscape was quasi-pristine much of the year, with low numbers of ships traversing the area. However, during summer/autumn, signals from airgun surveys were detected > 12 h/day. Mean received peak-to-peak SPLs for loud airgun pulses reached 160.46 ± 0.48 dB 1 μPa when seismic-survey ships were close (at ~ 57 km). Bowhead whales were present almost daily October–April in all years, with singing occurring in almost every hour November–March. Currently, loud anthropogenic sound sources do not temporally overlap the peak period of bowhead singing. This study provides important baseline data for future monitoring. - Highlights: • At present, underwater sound levels in western Fram Strait are low to moderate (< 60 dB). • Shipping activity is low, but seismic surveys occur nearby in summer/autumn. • Critically endangered bowhead whales are present in the area throughout most of the year. • Currently, little human activity overlaps with bowhead winter occurrence.

[en] Conversion factors were developed for Dall's porpoise tissues to convert trace element concentrations between dry and wet weight basis. - Concentration of trace elements measured by dry weight basis has become more commonly used in recent studies on cetaceans than wet weight basis, which was used more in earlier studies. Because few authors present moisture content data in their papers, it is difficult to compare the concentrations of trace elements between various studies. Therefore, we felt that it would be useful if a reference conversion factor (CF) for tissue types could be found to convert between wet weight and dry weight data on trace element concentrations. We determined the moisture contents of 14 tissues of Dall's porpoise (Phocoenoides dalli), and then, calculated the CF values for those tissues. Because the moisture content of each tissue differs from other tissues, it is necessary to use a specific CF for each tissue rather than a general CF for several tissues. We have also found that CF values for Dall's porpoise tissues are similar to the same tissues in other cetaceans. Therefore CF values from Dall's porpoise can be reliably used to convert between wet and dry weight concentrations for other cetacean tissues as reference data

[en] To discuss the maternal-fetal transfer of persistent organic pollutants (POPs) in viviparous fish, the whole-body burdens of POPs were determined in gravid surfperches from Otsuchi Bay, Japan, and in their fetuses. The concentrations were 2.75-15.5 times higher in the maternal tissue. To compare the characteristics of the maternal-fetal transfer between species with different gestation systems, reports on the striped dolphin and long-finned pilot whales were studied. The transfer rates of POPs in surfperches were 0.6-6.0%, while in marine mammals they were 3.0-9.4%. The difference in transfer rates may derive from the difference in their reproductive systems. On the other hand, as in marine mammals, selective transfer of POPs was seen in surfperches. The transfer rates were higher in less hydrophobic compounds such as dieldrin, and lower in more hydrophobic compounds such as DDTs. A new transfer factor is also discussed which instantly indicates the difference in the concentrations between mother and fetus. -- The reproductive transfer of POPs in matrotrophic viviparous surfperch was determined for the first time

[en] Wavy leading edge modifications of airfoils through imitating humpback whale flippers has been considered as a viable passive way to control flow separation. In this paper, flows around a baseline 63_4-021 airfoil and one with leading-edge sinusoidal protuberances were simulated using S-A turbulence model. When studying the static stall characteristics, it is found that the modified airfoil does not stall in the traditional manner, with increasing poststall lift coefficients. At high angles of attack, the flows past the wavy leading edge stayed attached for a distance, while the baseline foil is in a totally separated flow condition. On this basis, the simulations of pitch characteristic were carried out for both foils. At high angles of attack mild variations in lift and drag coefficients of the modified foil can be found, leading to a smaller area of hysteresis loop. The special structure of wavy leading edge can help maintain high consistency of the flow field in dynamic pitching station within a particular range of angles of attack

[en] Marine mammals encompass 125 species in 20 families that merge in 5 different mammalian groups: (a) Cetaceans (whales, dolphins and porpoises); (b) Sirenians (manatees and dugongs); (c) Pinnipeds (sea lions, walruses and seals); (d) Marine and sea otters; (e) Polar bears. These marine mammalian groups are more closely related to one or another terrestrial mammalian group (e.g. horses, bears or elephants) than they are to each other. However, all marine mammals have one thing in common: they derive virtually all of their food from the marine environment