Mass stranding and unusual sightings of northern bottlenose whales (Hyperoodon ampullatus) in Skjálfandi Bay, Iceland

Poster.-- World Marine Mammal Conference, Barcelona, 9-12 December 2019Peer reviewe

The common murre (Uria aalge), an auk seabird, reacts to underwater sound

Author Posting. © Acoustical Society of America, 2020. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 147(6), (2020): 4069, doi:10.1121/10.0001400.Marine mammals have fine-tuned hearing abilities, which makes them vulnerable to human-induced sounds from shipping, sonars, pile drivers, and air guns. Many species of marine birds, such as penguins, auks, and cormorants, find their food underwater where light is often limited, suggesting sound detection may play a vital role. Yet, for most marine birds, it is unknown whether they are using, and can thereby be affected by, underwater sound. The authors conducted a series of playback experiments to test whether Alcid seabirds responded to and were disrupted by, underwater sound. Underwater broadband sound bursts and mid-frequency naval 53 C sonar signals were presented to two common murres (Uria aalge) in a quiet pool. The received sound pressure levels varied from 110 to 137 dB re 1 μPa. Both murres showed consistent reactions to sounds of all intensities, as compared to no reactions during control trials. For one of the birds, there was a clearly graded response, so that more responses were found at higher received levels. The authors' findings indicate that common murres may be affected by, and therefore potentially also vulnerable to, underwater noise. The effect of man-made noise on murres, and possibly other marine birds, requires more thorough consideration.This project was funded by the U. S. Navy's Living Marine Resources Program (BAA N39433015R7203) and Woods Hole Oceanographic Institution. Birds were loaned from Copenhagen Zoo. Work was conducted under permission from the WHOI Institutional Animal Care and Use Committee, and animal permit to University of Southern Denmark No. 2300-50120-00003-09 from the Danish Ministry of Food and Agriculture. Statistical analysis was assisted by Simeon Smeele (MPI Konstanz, Germany) and Owen Jones (University of Southern Denmark).2020-12-2

A field study of auditory sensitivity of the Atlantic puffin, Fratercula Arctica

Author Posting. © Company of Biologists, 2020. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology (2020): jeb.228270, doi:10.1242/jeb.228270.Hearing is vital for birds as they rely on acoustic communication with parents, mates, chicks, and conspecifics. Amphibious seabirds face many ecological pressures, having to sense cues in air and underwater. Natural noise conditions have helped shape this sensory modality but anthropogenic noise is increasingly impacting seabirds. Surprisingly little is known about their hearing, despite their imperiled status. Understanding sound sensitivity is vital when we seek to manage manmade noise impacts. We measured the auditory sensitivity of nine wild Atlantic puffins, Fratercula arctica, in a capture-and-release setting in an effort to define their audiogram and compare these data to the hearing of other birds and natural rookery noise. Auditory sensitivity was tested using auditory evoked potential (AEP) methods. Responses were detected from 0.5 to 6 kHz. Mean thresholds were below 40 dB re 20 µPa from 0.75 to 3 kHz indicating that these were the most sensitive auditory frequencies, similar to other seabirds. Thresholds in the ‘middle’ frequency range 1-2.5 kHz were often down to 10-20 dB re 20 µPa. Lowest thresholds were typically at 2.5 kHz. These are the first in-air auditory sensitivity data from multiple wild-caught individuals of a deep-diving Alcid seabird. The audiogram was comparable to other birds of similar size, thereby indicating that puffins have fully functioning aerial hearing despite the constraints of their deep-diving, amphibious lifestyles. There was some variation in thresholds, yet animals generally had sensitive ears suggesting aerial hearing is an important sensory modality for this taxon.This work was supported by the U.S. Navy’s Living Marine Resources Program and the Woods Hole Oceanographic Institution.2021-06-1

Killer whales (Orcinus orca) produce ultrasonic whistles

This study reports that killer whales, the largest dolphin, produce whistles with the highest fundamental frequencies ever reported in a delphinid. Using wide-band acoustic sampling from both animal-attached (Dtag) and remotely deployed hydrophone arrays, ultrasonic whistles were detected in three Northeast Atlantic populations but not in two Northeast Pacific populations. These results are inconsistent with analyses suggesting a correlation of maximum frequency of whistles with body size in delphinids, indicate substantial intraspecific variation in whistle production in killer whales, and highlight the importance of appropriate acoustic sampling techniques when conducting comparative analyses of sound repertoires

Ginnerup Revisited. New Excavations at a Key Neolithic Site on Djursland, Denmark

New excavations of an enclosure-related site at Ginnerup on Djursland, Denmark, in 2020 resulted in the identification of several features containing depositions of marine shells. One of these, A4, is a natural depression with a fill comprised of four consecutively deposited layers, forming an undisturbed stratigraphy, dated by several 14C dates to between c. 3150 and 2950 BC. The oldest layer contained finds from phase MN A Ib of the Funnel Beaker culture, while the remaining three layers yielded finds from the latest Funnel Beaker culture on Djursland (MN A II/III, Ferslev style) with an upwardly increasing content of Pitted Ware culture elements, thereby allowing the emergence of this culture in Denmark to be followed for the first time. Preservation conditions for organic material were excellent due to a content of marine shells, mainly from oysters and mussels, in all layers. In this preliminary account, a survey of the material culture in the four layers is presented, together with 14C dates, zoological investigations of mammal and fish bones, isotope analyses (d13C, d15N and d34S) and aDNA analyses of mammal bones and examinations of plant macro-remains. The abundant bones of wild horses also hold a huge potential for zoological and genetic studies, the results of which can qualify the ongoing debate about the rewilding of horses in present-day Europe

Abundance of whales in West and East Greenland in summer 2015

An aerial line transect survey of whales in West and East Greenland was conducted in August-September 2015. The survey covered the area between the coast of West Greenland and offshore (up to 100 km) to the shelf break. In East Greenland, the survey lines covered the area from the coast up to 50 km offshore crossing the shelf break. A total of 423 sightings of 12 cetacean species were obtained and abundance estimates were developed for common minke whale, (Balaenoptera acutorostrata) (32 sightings), fin whale (Balaenoptera physalus) (129 sightings), humpback whale (Megaptera novaeangliae) (84 sightings), harbour porpoise (Phocoena phocoena) (55 sightings), long-finned pilot whale, (Globicephala melas) (42 sightings) and white-beaked dolphin (Lagenorhynchus albirostri) (50 sightings). The developed at-surface abundance estimates were corrected for both perception bias and availability bias if possible. Data on surface corrections for minke whales and harbour porpoises were collected from whales instrumented with satellite-linked time-depth-recorders. Options for estimation methods are presented and the preferred estimates are: minke whales: 5,095 (95% CI: 2,171-11,961) in West Greenland and 2,762 (95% CI: 1,160-6,574) in East Greenland, fin whales: 2,215 (95% CI: 1,017-4,823) in West Greenland and 6,440 (95% CI: 3,901-10,632) in East Greenland, humpback whales: 993 (95% CI: 434-2,272) in West Greenland and 4,223 (95% CI: 1,845-9,666) in East Greenland, harbour porpoises: 83,321 (95% CI: 43,377-160,047) in West Greenland and 1,642 (95% CI: 319-8,464) in East Greenland, pilot whales: 9,190 (95% CI: 3,635-23,234) in West Greenland and 258 (95% CI: 50-1,354) in East Greenland, white-beaked dolphins 15,261 (95% CI: 7,048-33,046) in West Greenland and 11,889 (95% CI: 4,710-30,008) in East Greenland. The abundance of cetaceans in coastal areas of East Greenland has not been estimated before, but the limited historical information from the area indicates that the achieved abundance estimates were remarkably high. When comparing the abundance estimates from 2015 in West Greenland with a similar survey conducted in 2007, there is a clear trend towards lower densities in 2015 for the three baleen whale species and white-beaked dolphins. Harbour porpoises and pilot whales, however, did not show a similar decline. The decline in baleen whale and white-beaked dolphin abundance is likely due to emigration to the East Greenland shelf areas where recent climate driven changes in pelagic productivity may have accelerated favourable conditions for these species

Trans fatty acids in adipose tissue and risk of myocardial infarction: A case-cohort study

BACKGROUND:The risk of coronary heart disease associated with intake of individual trans fatty acids (TFAs) is not clear. Adipose tissue content of TFAs is a biomarker of TFA intake and metabolism. OBJECTIVE:We investigated the rate of myocardial infarction (MI) associated with the adipose tissue content of total 18:1t, isomers of 18:1t (18:1 Δ6-10t and 18:1 Δ11t) and 18:2 Δ9c, 11t. METHODS:A case-cohort study, nested within the Danish Diet, Cancer and Health cohort (n = 57,053), was conducted, which included a random sample (n = 3156) of the total cohort and all incident MI cases (n = 2148) during follow-up (14 years). Information on MI cases was obtained by linkage with nationwide registers and validated. Adipose tissue was taken from the participants buttocks and the fatty acid composition was determined by gas chromatography. RESULTS:Women with higher adipose tissue content of total 18:1t had a 57% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.57; 95% confidence interval, 1.12-2.20; P-trend = 0.011) and women with higher content of 18:1 Δ6-10t had a 76% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.76; 95% confidence interval, 1.23-2.51; P-trend = 0.002). No association between 18:1 Δ11t content and MI rate was observed. In men, no associations between adipose tissue content of total 18:1t and 18:1 Δ6-10t and MI rate were observed. However, men with higher content of 18:1 Δ11t had a 48% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.48; 95% confidence interval, 1.17-1.86; P-trend = 0.003). Adipose tissue content of 18:2 Δ9c, 11t was not associated with MI rate in women or men. CONCLUSIONS:Adipose tissue content of 18:2 Δ9c, 11t was not associated with MI rate in women or men, whereas higher contents of isomers of 18:1t were associated with higher MI rates but the associations for individual 18:1t isomers differed, however, in women and men