Whaling in Iron Age to post-medieval Scotland

Cetacean remains have been recovered from archaeological sites all over Europe, but are especially abundant in Scotland. These remains originate from all periods and have often been worked into artefacts or tools, including chopping blocks, plaques, combs, pegs, snecks and perforated vertebral epiphyseal discs. It still remains unclear which species were exploited and to what extent active whaling was undertaken in the region. To address these questions Zooarchaeology by Mass Spectrometry (ZooMS) was undertaken on 35 cetacean specimens from five sites in Scotland (Jarlshof, Brough of Birsay, Quoygrew, Deerness and Freswick Links), dating from the Iron Age to the post-medieval period. Furthermore, morphological analysis was performed on the material in order to optimise the ZooMS identifications. A large variety of species were identified, including high numbers of Balaenidae sp and Globicephalinae sp. Comparison with other ZooMS studies in north-western Europe revealed equally high specimen numbers for these species, but also fin whale (Balaenoptera physalus), sperm whale (Phy-seter macrocephalus) and humpback whale (Megaptera novaeangliae). Moreover, one grey whale (Eschrichtius robustus) was identified in the Scottish specimens, adding to an increasing number of specimens indicating that the grey whale was once abundant in European waters. Furthermore, only one specimen of the common minke whale (Balaenoptera acutorostrata) was identified, despite modern stranding data which suggests this is the most common large whale species in Scottish waters. The large variety of species identified suggests that opportunistic scavenging was likely the primary method of acquiring cetaceans, though historical and ethnographic sources suggest that two distinct forms of active whaling may have occasionally been undertaken. The high number of Globicephalinae specimens from Jarlshof raise the possibility that drive-hunting might have already been undertaken at the site during the Iron Age. View supplementary materials here: Table 1 | Table 2 | Table 3 |

Morphological differences in skulls and feeding apparatuses between Antarctic and common minke whales, and the implication for their feeding ecology

The differences in rorqual feeding ecology have been linked to the presence of different morphological markers. The Antarctic minke whale (Balaenoptera bonaerensis Burmeister, 1867) and common minke whale (Balaenoptera acutorostrata Lacépède, 1804) are closely related species, but their morphological differences have not been fully investigated. In this study, we compared 21 skull and 11 feeding apparatuses (baleen and mouth-related parts) measurement points between these two species using hundreds of individuals covering a wide range of body lengths in both sexes. Their engulfment capacities were estimated using these measurements. Our results show that Antarctic minke whales have (1) proportionally larger skulls to the body length, (2) more dorsoventrally and laterally curved rostra, (3) proportionally larger feeding apparatuses to the condylobasal length, and (4) significantly larger engulfment capacity than common minke whales. These differences could indicate that Antarctic minke whales have developed a feeding strategy suitable for feeding on krill, which forms large schools. In contrast, common minke whales have adapted to prey on small pelagic fishes that are agile and form small schools.

Changes in the Movement and Calling Behavior of Minke Whales (Balaenoptera acutorostrata) in Response to Navy Training

Many marine mammals rely on sound for foraging, maintaining group cohesion, navigation, finding mates, and avoiding predators. These behaviors are potentially disrupted by anthropogenic noise. Behavioral responses to sonar have been observed in a number of baleen whale species but relatively little is known about the responses of minke whales (Balaenoptera acutorostrata). Previous analyses demonstrated a spatial redistribution of localizations derived from passive acoustic detections in response to sonar activity, but the lack of a mechanism for associating localizations prevented discriminating between movement and cessation of calling as possible explanations for this redistribution. Here we extend previous analyses by including an association mechanism, allowing us to differentiate between movement responses and calling responses, and to provide direct evidence of horizontal avoidance responses by individual minke whales to sonar during U.S. Navy training activities. We fitted hidden Markov models to 627 tracks that were reconstructed from 3 years of minke whale (B. acutorostrata) vocalizations recorded before, during, and after naval training events at the U.S. Navy’s Pacific Missile Range Facility, Kauai, Hawaii. The fitted models were used to identify different movement behaviors and to investigate the effect of sonar activity on these behaviors. Movement was faster and more directed during sonar exposure than in baseline phases. The mean direction of movement differed during sonar exposure, and was consistent with movement away from sonar-producing ships. Animals were also more likely to cease calling during sonar. There was substantial individual variation in response. Our findings add large-sample support to previous demonstrations of horizontal avoidance responses by individual minke whales to sonar in controlled exposure experiments, and demonstrate the complex nature of behavioral responses to sonar activity: some, but not all, whales exhibited behavioral changes, which took the form of horizontal avoidance or ceasing to call.

Measurement error model for the Norwegian common minke whale (Balaenoptera acutorostrata acutorostrata) surveys 2008-2013

A discrete measurement error model for radial distance and angle to detected objects in line transect surveys is considered. This approach directly quantifies the effect of measurement error on the estimated effective strip half-width. We apply the method to experimental data collected over the period 2008-2013 in North Atlantic both under the assumption of multiplicative and additive measurement errors. Our results indicate that the abundance estimates considering the measurement error are consistently larger than the abundance estimates without any measurement error correction.

Cetaceans of the Barents Sea: Fauna and population status at the beginning of the XXI century

The Polar branch of Russian Federal Research Institute of Fisheries and Oceanography (VNIRO) carries out annually comprehensive surveys in the Barents Sea. This allows obtaining relevant data on distribution and occurrence of marine mammals, in particular cetaceans – the key link in the World Ocean ecosystem. In recent years, marine mammals monitoring has become increasingly important due to climate change and temperature rise in seas and oceans, that can result in habitat displacement and even possible extinction of certain species. This article summarizes the results of the vessel surveys of cetaceans carried out by the Polar branch of VNIRO in the Barents Sea in 2010–2019, as well as provides retrospective data on baleen whales (Mysticeti) and toothed whales (Odontoceti). Based on vessel survey material and taking into account data from literature sources, the current composition of the Barents Sea cetacean fauna is presented; at the beginning of the XXI century, it may include up to 16 species of 7 families. The analysis of vessel survey data made it possible to determine the status of marine mammals of this water area and to identify the frequency of their occurrence. The article presents population abundance for most species of baleen and toothed whales and shows the most likely spots of cetacean occurrence. According to the data obtained, white-beaked dolphin Lagenorhynchus albirostris is the most abundant, frequently sighted, and a year-round species: it accounts for more than 80 % of the total number of surveyed animals and about 50 % of all sighted cetaceans. Beluga whale Delphinapterus leucas and harbor porpoise Phocoena phocoena are also classified as permanent residents of the water area, and their localization is mainly confined to the Kola Peninsula coastal zone. May to October, the Barents Sea is regularly visited by species arriving from other Atlantic Ocean areas for feeding: minke whale Balaenoptera acutorostrata, fin whale Balaenoptera physalus, and humpback whale Megaptera novaeangliae. Narwhal Monodon monoceros and northern bottlenose whale Hyperoodon ampullatus are rarely sighted in the Russian Arctic western area.

What a stranded whale with scoliosis can teach us about human idiopathic scoliosis

Scoliosis is a deformation of the spine that may have several known causes, but humans are the only mammal known to develop scoliosis without any obvious underlying cause. This is called ‘idiopathic’ scoliosis and is the most common type. Recent observations showed that human scoliosis, regardless of its cause, has a relatively uniform three-dimensional anatomy. We hypothesize that scoliosis is a universal compensatory mechanism of the spine, independent of cause and/or species. We had the opportunity to study the rare occurrence of scoliosis in a whale (Balaenoptera acutorostrata) that stranded in July 2019 in the Netherlands. A multidisciplinary team of biologists, pathologists, veterinarians, taxidermists, radiologists and orthopaedic surgeons conducted necropsy and imaging analysis. Blunt traumatic injury to two vertebrae caused an acute lateral deviation of the spine, which had initiated the development of compensatory curves in regions of the spine without anatomical abnormalities. Three-dimensional analysis of these compensatory curves showed strong resemblance with different types of human scoliosis, amongst which idiopathic. This suggests that any decompensation of spinal equilibrium can lead to a rather uniform response. The unique biomechanics of the upright human spine, with significantly decreased rotational stability, may explain why only in humans this mechanism can be induced relatively easily, without an obvious cause, and is therefore still called ‘idiopathic’.

Ecological habitat partitioning and feeding specialisations of coastal minke whales (Balaenoptera acutorostrata) using a designated MPA in northeast Scotland

In the design of protected areas for cetaceans, spatial maps rarely take account of the life-history and behaviour of protected species relevant to their spatial ambit, which may be important when modelling population trends or assessing susceptibility to anthropogenic threats. In the present study, we examined the distribution and feeding behaviours of minke whales by age-class (adults versus juveniles) from long-term studies in the Moray Firth in northeast Scotland, where a Marine Protected Area (MPA) has recently been designated. Data were collected from dedicated boat surveys between 2000 and 2019, during which 657 encounters with 774 whales of confirmed age-class (444 juveniles and 330 adults) were recorded from 50,041 km of survey effort, resulting in 224 individual follows. Feeding/foraging whales were documented in 84% of the encounters. Adults and juveniles were occasionally seen together, but their distributions were not statistically correlated, and GIS revealed spatial separation by age-class―with juveniles preferring shallow, inshore waters with sandy-gravel sediments and adults preferring deeper, offshore waters with steep benthic slope. Whilst adult minkes employed a range of “active” prey-entrapment specialisations, showing seasonal flexibility in their targeted prey with interindividual variation, juveniles almost exclusively used “passive” (low energy) feeding methods, targeting low-density patches of inshore prey. These findings corroborate the need to incorporate demographic/behavioural data into spatial models when identifying priority areas for protected cetaceans and may be important to adaptive management objectives for the species in the Moray Firth MPA.

What a Stranded Whale With Scoliosis Can Teach us About Human Idiopathic Scoliosis

Scoliosis is a deformation of the spine that may have several known causes, but humans are the only mammal known to develop scoliosis without any obvious underlying cause. This is called ‘idiopathic’ and is the most common type. Recent observations showed that human scoliosis, regardless of its cause, has a relatively uniform three-dimensional anatomy. We hypothesize that scoliosis is a universal compensatory mechanism of the spine, independent of cause and/or species. We had the opportunity to study the rare occurrence of scoliosis in a whale (Balaenoptera acutorostrata) that stranded in July 2019 in the Netherlands. A multidisciplinary team of biologists, pathologists, veterinarians, taxidermists, radiologists and orthopaedic surgeons conducted necropsy and imaging analysis. (Dorso-)lateral blunt traumatic injury to two vertebrae caused an acute lateral deviation of the spine, which had initiated the development of compensatory curves in regions of the spine without anatomical abnormalities. Three-dimensional analysis of these compensatory curves showed strong resemblance with different types of human scoliosis, amongst which idiopathic. This suggests that any decompensation of spinal equilibrium can lead to a uniform response, regardless of underlying cause or species. The unique biomechanics of the upright human spine, with significantly decreased rotational stability, explains why only in humans this universal mechanism of scoliosis can occur without an obvious cause, and is thus still called ‘idiopathic’.