Hyperoodon Research Articles

The genome sequence of the Northern Bottlenose Whale, Hyperoodon ampullatus (Forster, 1770)

We present a genome assembly from an individual female Hyperoodon ampullatus (the Northern Bottlenose Whale; Chordata; Mammalia; Artiodactyla; Ziphiidae). The genome sequence spans 2,828.70 megabases. Most of the assembly is scaffolded into 21 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.34 kilobases in length.

Acoustic occurrence of beaked whales off eastern Canada, 2015-2017

Several beaked whale species occur off eastern Canada. However, except for the northern bottlenose whale (NBW; Hyperoodon ampullatus), their distribution and annual occurrence remain largely unknown, which complicates management efforts to assess the status of poorly known species and effectively protect those species considered at risk. The main objective of this paper is to provide a year-round and pluriannual description of the minimum acoustic occurrence of the NBW, Sowerby’s (SBW; Mesoplodon bidens), Cuvier’s (CBW; Ziphius cavirostris), True’s (TBW; M. mirus) and Gervais’ (GBW; M. europaeus) beaked whales. Twenty-five acoustic recorders were deployed off eastern Canada between May 2015 and November 2017. Beaked whale echolocation clicks were detected using a combination of automated detectors and manual validation at 12 of these stations. Detections were generally restricted to deep continental slope waters. All detected species occurred in the southern part of the study area (off the Scotian Shelf and southern Grand Banks), while only NBWs were detected at the northern edge, off southern Labrador. Clicks identified as TBW or GBW were restricted to, but occurred annually in, the southern areas. All other species were present, at least seasonally, east and north of the Grand Banks. NBWs occurred every day in the Gully Canyon, where SBWs also occurred regularly. While these results should be interpreted as minimum species presence and considered with regards to detector performance, they provide important information regarding beaked whales’ use of areas off eastern Canada where these species have generally received no or very limited monitoring effort.

Quantifying northern bottlenose and sperm whale acoustic behavioural responses to anthropogenic noise in Baffin Bay, Canada

Marine mammals rely on their auditory system for a myriad of life functions (e.g., navigating, foraging, socializing) and consequently, are vulnerable to loud human activities (e.g., vessel traffic, fishing, military activities). These activities can impede communication, cause behavioural disturbances, and can even cause injuries. As the Arctic warms and sea ice coverage decreases, more opportunities for human activities are arising. How noise impacts the acoustic behaviour of Arctic marine mammals is unclear. In October 2022 and 2023 controlled noise exposure experiments were conducted using military sonar (source level of 176.4 dB re 1 μPa) on northern bottlenose and sperm whales in Baffin Bay while they were foraging around vessels actively fishing. Hydrophone suction-cup biologgers (DTAGs; n = 5, ∼72 cumulative hours) were used to capture vessel and sonar noises, and whale vocalizations before, during, and after the noise exposure periods. Using a click detector, focal whale clicks were identified and quantitatively compared to received noise levels. This information will then be used to determine noise thresholds for acoustical behavioural responses. These results will support risk-mitigation strategies for the Department of National Defence Canada and Fisheries and Oceans Canada, as well as address Inuit concerns about the effects of military sonar on marine mammals.

Identifying important habitat for northern bottlenose and Sowerby's beaked whales in the western North Atlantic

Abstract Understanding habitat requirements for species at risk is crucial for effective conservation management, even though the location and extent of vital habitats may be unknown for rare or elusive species. In the case of marine species, determining important habitat often relies on limited occurrence data or extrapolation from species distribution models (SDMs). SDMs predict habitat by associating species records with environmental variables, assuming a functional ecological relationship. This study focuses on northern bottlenose whales (NBW; Hyperoodon ampullatus) and Sowerby's beaked whales (SBW; Mesoplodon bidens) in the western North Atlantic. As both NBW and SBW are at risk in Canada, the objective was to identify the extent and function of important habitats to guide conservation efforts. The analysis mapped all available geographic occurrence data and used passive acoustic monitoring (PAM) data to inform the development of ensemble SDMs to predict potential habitat and assess the persistence of realized habitat use. Important habitats for NBW and SBW were found primarily concentrated along the continental shelf edges, at an average depth of 1200 m ± 460 SD. All habitat areas support foraging and movement and critical life history functions for both species. The Gully and other submarine canyons off eastern Nova Scotia emerged as important areas for both species, validating the existing Critical Habitat for NBW. However, spatial–temporal patterns diverged on either side of this region. North‐eastern Newfoundland was identified as the next closest area of near‐year‐round presence for NBW, whereas the south‐western Scotian Shelf region, Georges Bank and the Fundian Channel supported persistent foraging by SBW. By integrating multiple data sources (sightings, acoustic detections and SDMs) and demonstrating the temporal persistence of habitat use by NBW and SBW, this study provides valuable insights for identifying, protecting and managing important habitat for beaked whales.

Sperm and northern bottlenose whale interactions with deep-water trawlers in the western North Atlantic.

Commercial fisheries have increased in all the world's oceans with diverse unintended impacts on marine ecosystems. As a result of resource overlap, interactions between cetaceans and fisheries are a common occurrence and, in many cases, can give rise to significant conservation issues. Research on the distribution and types of such interactions is important for efficient management. In this study, we describe the behaviors of two whale species: sperm whales (Physeter macrocephalus) and northern bottlenose whales (Hyperoodon ampullatus), interacting with benthic trawlers fishing off the eastern Grand Banks of the western North Atlantic in 2007. Whale interactions were only observed when vessels were targeting Greenland halibut (Reinhardtius hippoglossoides) in deep-water fishing areas and were most common during net hauling. Sperm whales and northern bottlenose whales appeared to engage in feeding behavior close to the surface during hauling, especially during the latter stages, suggesting they targeted fish escapees rather than discards. Using photo-identification methods, seven individual sperm whales were identified with multiple resights of six individuals being recorded over an almost two month period. The maximum distance between two resights was 234 km, suggesting individual sperm whales were repeatedly targeting and even following fishing vessels over multiple days and between fishing areas. By contrast, there were no photographic resights of individual northern bottlenose whales within this study, or with substantial photo-identification catalogues from other adjacent high density areas, suggesting that individuals of this species may be less likely to follow vessels or move between areas. This study documents the earliest confirmed records of northern bottlenose whales in this remote region. These interactions and high encounter rates may indicate that adjacent populations are recovering from the previous century of commercial whaling. Our study provides new insights and details on whale-fisheries interactions, which can inform future research and help managers understand the real and perceived impacts of depredation behaviour on fisheries and whales.

Population size and residency patterns of northern bottlenose whales (Hyperoodon ampullatus) using the Gully, Nova Scotia

A population of northern bottlenose whales (Hyperoodon ampullatus) uses the Gully, a submarine canyon off the coast of Nova Scotia, Canada. Eleven years of photo-identification records has permitted estimation of population size using mark-recapture techniques. The population estimate was small (133 individuals, 95% CI = 111-166 from left side identifications; 127 individuals, 95% CI = 106-160 from right side identifications). The population was not closed, with the combined mortality, mark change and emigration rate estimated at 13% per year for left side identifications (95% CI = 9-17) and 14% for right side identifications (95% CI = 10-18). There was no significant increase or decrease in the population size between 1988-1999 (change in population size: left side: –0.13% per year, 95% CI = -3.4 to 3.9; right side: –0.43% per year, 95% CI = -4.5 to 3.1). The sex ratio was roughly 1:1, with equal numbers of sub-adult and mature males. Over the summer field season, individuals emigrated from, and re-immigrated into the Gully, spending an average of 20 days within the Gully before leaving (left side identifications 19 days, SE = 17; right side identifications 23 days, SE = 10). Approximately 34% of the population was present in the Gully at any time. Individuals of all age and sex classes displayed similar residency patterns although there were annual differences as individuals spent less time in the Gully in 1996 than in 1990 and 1997. Sighting rates were similar in all years with extensive fieldwork, indicating little variability in the number of whales in the Gully each summer. Accurate estimates of population size and residency patterns will be useful in determining the regulations and required coverage for a marine protected area in the Gully.

Estimates of abundance south of 60°S for cetacean species sighted frequently on the 1978/79 to 1997/98 IWC/IDCR-SOWER sighting surveys

Estimates of abundance are calculated for six cetacean species in the Southern Ocean south of 60° in the austral summer, using the IWC database estimation package (DESS). The sightings data in DESS were collected during the 1978/79 to 1997/98 IWC/IDCR and SOWER circumpolar surveys. Abundance estimates are developed for the first (1978/79–1983/84), second (1985/86–1990/91) and currently incomplete third (1991/92–1997/98) circumpolar sets of surveys. The strata surveyed in these three sets cover about 65%, 81% and 68% respectively of the open ocean area south of 60°S. The surveys were designed for Antarctic minke whales and may not be optimal for all these species. Furthermore, the estimates presented below (CVs in brackets) should not necessarily be considered as estimates for the whole Southern Hemisphere. Some results are also presented for hourglass dolphins and sei whales, but estimates of abundance are not considered reliable for those two species. Effective search half-width and mean school size were estimated by pooling across strata and years. Pooling is effected separately for each circumpolar set of surveys. Additional pooling across closing and passing modes did not introduce substantial bias. The most frequently sighted species were minke, southern bottlenose, sperm, humpback and killer whales; the effective search half-widths for all five increase over time. The sensitivity of the abundance estimates to a number of factors is investigated, none of which appears to impact the results substantially, except that the incorporation of ‘like species’ would increase the estimate for blue whales from the third circumpolar set of surveys by 25% and for fin whales by 61%. In general, the assumption that 100% of schools on the trackline are sighted introduces variable negative bias to estimates for all species. Only two significant trends in abundance over time (for comparable areas) were detected, but both may be artefacts of changes in survey design.

Long term trends in floating plastic pollution within a marine protected area identifies threats for Endangered northern bottlenose whales

“The Gully”, situated off Nova Scotia, Canada, is the largest submarine canyon in the western North Atlantic. This unique oceanographic feature, which became a Marine Protected Area (MPA) in 2004, is rich in marine biodiversity and is part of the critical habitat of Endangered northern bottlenose whales (Hyperoodon ampullatus). To understand the potential impact of plastic pollution in the MPA and on this Endangered cetacean, we evaluated trends over time in the abundance and composition of plastics and compared these to the stomach contents of recently stranded northern bottlenose whales. From the 1990s–2010s, the median abundance of micro-sized (<5 mm) and small plastics (5 mm–2.5 cm) increased significantly, while the median abundance of large plastics (>2.5 cm) decreased significantly. Plastic abundance from the 2010s for micro-sized and small plastics varied from 5586–438 196 particles km−2, higher than previously measured estimates for surrounding offshore areas. Polymers identified using FTIR spectroscopy included polyethylene, polypropylene, polyethylene terephthalate polyester, nylon, alkyds (paint), and natural and semi-synthetic cellulosic fibers. The abundance of large debris ranged from 0 to 108.6 items km−2 and consisted of plastic sheets and bags, food wrappers and containers, rope, fishing buoys, and small plastic fragments. Whale stomach contents contained fragments of fishing nets, ropes, bottle caps, cups, food wrappers, smaller plastic fragments, fibers, and paint flakes, consistent with the composition and character of items collected from their critical habitat. Despite being far from centres of human population, the unique oceanographic features of The Gully (i.e. currents and bathymetric complexity) may concentrate plastic debris, increasing exposure rates of whales to plastic pollution. The increase in micro-sized and small plastics over time suggests associated health and welfare impacts of ingested plastics should be accounted for in future recovery plans for this Endangered species.

Geographic and temporal variations in strandings of beaked whales (Ziphiidae) on the coasts of the UK and the Republic of Ireland from 1800-2002

This study analyses published records of beaked whale strandings from the coasts of the UK and the Republic of Ireland between 1800 and 2002. Strandings of northern bottlenose whales (Hyperoodon ampullatus) were lowest in April and highest in September. The number of strandings between months differed significantly from an even spread over all months of the year, with more strandings between July and October. Most strandings in late summer and autumn occurred on North Sea coasts and their stomach contents included the squid Gonatus fabricii, which is found only in more northern waters. This suggests that these whales may be migrating southward at this time of year. Most strandings of Sowerby’s beaked whales (Mesoplodon bidens) also occurred in late summer and autumn, although this was not significant. Strandings of Cuvier’s beaked whales (Ziphius cavirostris) occurred almost exclusively on the Atlantic coasts of the UK and in Ireland. There were significantly more Cuvier’s beaked whale strandings than expected in January and February and in June and July. A Cuvier’s beaked whale which stranded in northern Scotland in February contained similar prey to two whales stranded in north-western Spain at the same time of year, suggesting this animal could have been feeding in more southern waters prior to stranding. Seasonal patterns of strandings of northern bottlenose and Cuvier’s beaked whales were significantly different with more of the former stranding in August to October and more of the latter from November to July. This is consistent with a hypothesis of temporal segregation between the two species to reduce potential competition for prey.

How big is a beaked whale? A review of body length and sexual size dimorphism in the family Ziphiidae

There is a paucity of data on the family Ziphiidae (the beaked whales) and even basic information, such as body length, is not available for some species. This review examines published records of body length for 20 of the 21 currently recognised species of beaked whale. It considers maximum, median and modal body lengths, where possible by sex. For Cuvier’s, Blainville’s and Gray’s beaked whales, modal and median lengths were much shorter than the maximum reported lengths; this may reflect misidentification of the largest animals. Although males of some species reached a greater maximum size, there was only a significant difference in median body length for three species: True’s beaked whale; the strap-toothed whale; and Gervais’ beaked whale. In all three cases, females had a significantly larger median length. The apparent lack of consistent sexual dimorphism in body length suggests that, while male beaked whales use their tusks as weapons to compete aggressively for access to receptive females, large size does not give a competitive advantage. This may be a result of the way the sexually dimorphic tusks are used during combat. The only exception to this rule appears to be the northern bottlenose whale, for which males consistently reach greater body lengths than the largest females. Male-male combat appears to take a different form in this species.

Abundance and densities of beaked and bottlenose whales (family Ziphiidae)

Estimating the abundance and density of beaked whales is more difficult than for most other cetacean species. Consequently few estimates appear in the published literature. Field identification is problematic, especially for the smaller species, and visual detection rates decrease dramatically with Beaufort sea state; prior experience is very important to an observer’s ability to detect beaked whales. Passive acoustics may hold future promise for detecting beaked whales from their vocalisations, especially for the larger species. Most published estimates of abundance or density are based on visual line-transect studies that found narrower effective strip widths and lower trackline detection probabilities for beaked whales than for most other cetaceans. Published density estimates range from 0.4-44 whales per 1,000km2 for small beaked whales and up to 68 whales per 1,000km2 for large beaked whales. Mark-recapture methods based on photo-identification have been used to estimate abundance in a few cases in limited geographical areas. Focused research is needed to improve beaked whale abundance and density estimates worldwide.

Opportunistic sightings from fisheries surveys inform habitat suitability for northern bottlenose whales Hyperoodon ampullatus and sperm whales Physeter macrocephalus in Baffin Bay and Davis Strait, Canadian Arctic

Knowledge of spatial habitat patterns is critical for understanding the ecology of cetaceans and informing conservation efforts. However, this can be difficult to obtain for species that live in deep, offshore Arctic waters where they are not easily observed. We investigated habitat suitability for 2 cetacean species, northern bottlenose whale Hyperoodon ampullatus and sperm whale Physeter macrocephalus, in Baffin Bay and Davis Strait, eastern Canadian Arctic. Presence locations were obtained from a unique marine mammal sightings data set where observations were opportunistically recorded during annual government-led fisheries surveys (1999-2017). Environmental variable data were used as predictors in presence-only habitat suitability modelling in Maxent software. A total of 12 sperm whales were observed at 9 unique locations, and 282 northern bottlenose whales were observed at 66 unique locations. The best habitat suitability model for sperm whale (area under the curve [AUC] = 0.72) and for northern bottlenose whale (AUC = 0.88) indicated higher suitability for both species in the central portion of the study area; higher suitability for sperm whales was also present in the southern part of the study area. A future projections scenario using environmental data from 2021 forecasted an increase in suitability in northern regions for both species. Post-model comparisons identified significant relationships between survey effort and habitat suitability, and squid biomass and habitat suitability for both species, although the variance explained by these models was low. We discuss the importance of monitoring cetacean range expansion of temperate whales in the Arctic and how this could lead to shifts in ecosystem dynamics and increased conflict with commercial fisheries.

Habitat use of the northern bottlenose whale Hyperoodon ampullatus near Jan Mayen, North Atlantic

Habitat use of the northern bottlenose whaleHyperoodon ampullatusin the Northeast Atlantic is poorly understood. This study aimed to identify locally utilised habitat features and create predictions of northern bottlenose whale habitat use over a wider area around the island of Jan Mayen, Norway. Bottlenose whales were sighted regularly near Jan Mayen in June 2014-2016 at higher rates than over a wider study region reported in other studies, indicating that the Jan Mayen habitat may be a hotspot of bottlenose whale presence in early boreal summer. Habitat models were created by fitting generalised additive models of selected environmental variables to sighting occurrence and additional whale sightings given a first encounter (total number of sightings - 1) recorded in June 2014-2016. Higher occurrence was estimated at steeper topography and April-average chlorophyll concentration below 0.4 mg m-3. Additional whale sightings given a first encounter were predicted to be higher at water depths (&lt;1000 m) with steep topography, and deeper water (depths between 1300 and 2000 m) with a gentle seafloor slope. Spatial predictions largely corresponded with field observations that indicated high usage around the submarine canyon regions in the east and southeast of Jan Mayen Island. This study highlights the likely importance of steep and deep bathymetric features in shaping patterns of habitat use of this deep-diving species. Predictions of habitat use over a wider area not covered by the analysed surveys require validation; however, these data could inform conservation and management efforts to minimise spatial overlap between potential high-use areas and potentially disruptive anthropogenic activities.

Genomics reveal population structure, evolutionary history, and signatures of selection in the northern bottlenose whale, Hyperoodon ampullatus.

Information on wildlife population structure, demographic history, and adaptations are fundamental to understanding species evolution and informing conservation strategies. To study this ecological context for a cetacean of conservation concern, we conducted the first genomic assessment of the northern bottlenose whale, Hyperoodon ampullatus, using whole-genome resequencing data (n=37) from five regions across the North Atlantic Ocean. We found a range-wide pattern of isolation-by-distance with a genetic subdivision distinguishing three subgroups: the Scotian Shelf, western North Atlantic, and Jan Mayen regions. Signals of elevated levels of inbreeding in the Endangered Scotian Shelf population indicate this population may be more vulnerable than the other two subgroups. In addition to signatures of inbreeding, evidence of local adaptation in the Scotian Shelf was detected across the genome. We found a long-term decline in effective population size for the species, which poses risks to their genetic diversity and may be exacerbated by the isolating effects of population subdivision. Protecting important habitat and migratory corridors should be prioritized to rebuild population sizes that were diminished by commercial whaling, strengthen gene flow, and ensure animals can move across regions in response to environmental changes.

Bycatch of marine mammals in the Northwest Atlantic during commercial fishery (based on literature materials and observations by the Polar branch of VNIRO in 2013-2020)

This paper describes one of the most acute problem for both environmental companies and fisheries - bycatch of marine mammals caused by bioresource exploitation in the Northwest Atlantic (NWA). There is no doubt that fishing has some impact on marine mammals, but information on bycatch of marine mammals is needed to understand the extent of the impact of different fishing gears. The paper is based on data from reports of observers of the Polar branch of VNIRO from fishing vessels in the 3LMNO NAFO zone (Newfoundland Island), as well as literary materials. As a result of the analysis, it has been found that small species of marine mammals, such as gray, common, harp seals from the Phocidae family, common dolphin, short-finned pilot whale (Delphinidae family) as well as harbour porpoise from the Phocoenidae family are most often injured by various fishing gears. Toothed whales (sperm whale, bottlenose whale) are the least susceptible to bycatch. Among the baleen whales, humpback whale, northern right whale and minke whale are often the victims of fishing. Gillnets, trawl fishing, and longlines are the greatest threats to small marine mammal species, while baleen whales are most vulnerable to traps, usually to catch ten-legged crustaceans Decapoda. Analysis of the literature has shown that, in general, the stocks of most marine mammal species in the NWA, excluding the northern right whale, are in a stable condition. The manuscript considers measures aimed at reducing bycatch of marine mammals.

Beaked whales and state-dependent decision-making: how does body condition affect the trade-off between foraging and predator avoidance?

Body condition is central to how animals balance foraging with predator avoidance—a trade-off that fundamentally affects animal fitness. Animals in poor condition may accept greater predation risk to satisfy current foraging ‘needs’, while those in good condition may be more risk averse to protect future ‘assets’. These state-dependent behavioural predictions can help interpret responses to human activities, but are little explored in marine animals. This study investigates the influence of body condition on how beaked whales trade-off foraging and predator avoidance. Body density (indicating lipid-energy stores) was estimated for 15 foraging northern bottlenose whales tagged near Jan Mayen, Norway. Composite indices of foraging (diving and echolocation clicks) and anti-predation (long ascents, non-foraging dives and silent periods reducing predator eavesdropping) were negatively related. Experimental sonar exposures led to decreased foraging and increased risk aversion, confirming a foraging/perceived safety trade-off. However, lower lipid stores were not related to a decrease in predator avoidance versus foraging, i.e. worse condition animals did not prioritize foraging. Individual differences (personalities) or reproductive context could offer alternative explanations for the observed state-behaviour relationships. This study provides evidence of foraging/predator-avoidance trade-offs in a marine top predator and demonstrates that animals in worse condition might not always take more risks.

Acoustic detections of beaked whales, narrow-band high-frequency pulses and other odontocete cetaceans in the Southern Ocean using an autonomous towed hydrophone recorder

Encased in a streamlined, flooded housing, a SoundTrap ST300HF hydrophone recording system was towed on voyages to South Georgia Island and the South Sandwich Islands and to the Antarctic Peninsula in December 2019–February 2020. Recordings were analyzed to identify acoustic detections of cetacean species. Acoustically identified species included sperm whales (Physeter macrocephalus), southern bottlenose whales (Hyperoodon planifrons), Arnoux's beaked whales (Berardius arnuxii), killer whales (Orcinus orca), and long-finned pilot whales (Globicephala melas). Acoustic detections also included several recognized types of beaked whale echolocation pulses (BW37/39 and BW58) as well as two likely beaked whale echolocation pulse types that do not match any previous descriptions. Narrow-band high-frequency echolocation signals (NBHF) (typical of porpoises and some dolphin species) were detected in many locations, and one of these coincided with a sighting of hourglass dolphins (Lagenorhynchus cruciger). This study shows the utility of an autonomous towed hydrophone system on a vessel of opportunity to study the distribution of cetaceans in rough seas that are difficult to study by visual survey methods.

Китообразные Баренцева моря: фауна и состояние популяций в начале XXI века

Комплексные научно-исследовательские работы, ежегодно проводимые Полярным филиалом ВНИРО (ПИНРО имени Н. М. Книповича) в Баренцевом море, позволяют получать актуальную информацию о распределении и встречаемости морских млекопитающих, в частности китообразных, которые являются важнейшим звеном в экосистеме Мирового океана. В последние годы необходимость проведения мониторинга морских млекопитающих приобретает всё бόльшую актуальность в связи с изменением климата и повышением температуры морей и океанов, что может привести к смещению ареалов и даже к возможному исчезновению тех или иных видов. В настоящей работе обобщены результаты судовых учётов китообразных, выполненных Полярным филиалом ВНИРО в Баренцевом море в 2010–2019 гг., а также приведены ретроспективные данные по фауне усатых (Mysticeti) и зубатых (Odontoceti) китов. На основе материалов судовых исследований и с учётом сведений из литературных источников определён современный состав китообразных Баренцева моря, который в начале XXI века может быть представлен 16 видами китообразных из 7 семейств. Анализ материалов судовых учётов позволил определить статус пребывания морских млекопитающих в акватории моря и выявить частоту их встречаемости. Приведена численность популяций большинства видов усатых и зубатых китов, указаны наиболее вероятные места их встреч. По данным исследований, самым массовым, часто и круглогодично встречающимся видом определён беломордый дельфин Lagenorhynchus albirostris: на его долю приходится более 80 % от общего количества учтённых морских млекопитающих и около 50 % от всех встреченных китообразных. К постоянно присутствующим в акватории моря видам также отнесены белуха Delphinapterus leucas и обыкновенная морская свинья Phocoena phocoena, местá локализации которых приурочены преимущественно к прибрежной зоне Кольского полуострова. С мая по октябрь в акватории Баренцева моря регулярно встречаются виды, прибывающие сюда для нагула из других районов Атлантики, — малый полосатик Balaenoptera acutorostrata, финвал Balaenoptera physalus и горбач Megaptera novaeangliae. Крайне редко в западном секторе Российской Арктики можно увидеть нарвала Monodon monoceros и высоколобого бутылконоса Hyperoodon ampullatus.

Origin and Persistence of Markings in a Long-Term Photo-Identification Dataset Reveal the Threat of Entanglement for Endangered Northern Bottlenose Whales (Hyperoodon ampullatus)

Photo-identification methods depend on markings that are stable over time. Using a large dataset of photographs taken over a 31-year period, we evaluate the reliability, rate of change and demographic trends in different mark types on northern bottlenose whales (Hyperoodon ampullatus) in the Endangered Scotian Shelf population, and assess the prevalence and severity of anthropogenically caused markings. Only fin notches and back indentations were stable over long timescales, leading to 48% of the overall population being assessed as reliably marked. Males and mature males were found to have higher incidence of most mark types compared to females and juveniles. The proportion of reliably marked individuals increased over time, a trend that should be accounted for in any temporal analysis of population size using mark-recapture methods. An overall increase in marked individuals may reflect the accumulation of scars on an aging population post whaling. Anthropogenic markings, including probable entanglement and propeller-vessel strike scars, occurred at a steady rate over the study period and were observed on 6.6% of the population. The annual gain rate for all injuries associated with anthropogenic interactions was over 5 times the annual potential biological removal (PBR) calculated for the endangered population. As entanglement incidents and propeller-vessel strike injuries are typically undetected in offshore areas, we provide the first minimum estimate of harmful human interactions for northern bottlenose whales. With low observer effort for fisheries across the Canadian Atlantic, photo-identification offers an important line of evidence of the risks faced by this Endangered whale population.

Cetacean strandings along the German North Sea coastline 1604–2017

AbstractThe occurrence of 19 cetacean species along the German North Sea coastline as well as the lower reaches of the major rivers discharging into the German Bight is reviewed for the period 1604–2017 based on records of dead animals, either stranded dead or put to death. The harbour porpoise (Phocoena phocoena) is considered the most abundant and only native species in German coastal and riverine waters. Based on written sources its presence can be traced back to at least 1651, although with statistical data only available from 1990. Finds of further 18 species have been documented: white-beaked dolphin (Lagenorhynchus albirostris), bottlenose dolphin (Tursiops truncatus), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), striped dolphin (Stenella coeruleoalba), Risso's dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas), killer whale (Orcinus orca), beluga whale (Delphinapterus leucas), narwhal (Monodon monoceros), Sowerby's beaked whale (Mesoplodon bidens), northern bottlenose whale (Hyperoodon ampullatus), sperm whale (Physeter macrocephalus), minke whale (Balaenoptera acutorostrata), sei whale (Balaenoptera borealis), fin whale (Balaenoptera physalus), blue whale (Balaenoptera musculus) and humpback whale (Megaptera novaeangliae). This review corrects several false species assignments earlier introduced in literature based on incorrect scientific or ambiguous German vernacular names and recovers lost records of beluga whale, northern bottlenose whale, sperm whale and fin whale.