scholarly journals On factors for separation of the stock of beluga whale Delphinapterus leucas in the Anadyr Gulf of the Bering Sea

2014 ◽  
Vol 179 (4) ◽  
pp. 113-119
Author(s):  
Denis I. Litovka ◽  
Ludmila N. Khitzova
Keyword(s):  
Genetic Analysis ◽  
Sea Ice ◽  
Beluga Whale ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Oncorhynchus Keta ◽  
Polar Cod ◽  
Anthropogenic Pressure ◽  
Beluga Whales ◽  
Anadyr Estuary

New eco-ethological data on the Anadyr stock of beluga whales are presented based on 14-year (2000-2013) studies by methods of satellite tracking telemetry, multi-spectral aerial surveys and genetic analysis, as well as traditional and ecosystem-based approaches. Possible factors of the separate stock formation in the Anadyr Gulf are discussed, as geographic isolation, environmental conditions, foraging resources, elimination of the beluga whales, and biological isolation (on the results of genetic analysis). The beluga whales are well-adapted to oceanographic conditions and ice regime of the Arctic waters that is realized in their relationship with edge of the sea ice, ability to live in both salt and fresh waters (they enter rivers), and versatility in feeding. Their ice-associating, high sociality, and white protective coloration provide protection against killer whales and other predators and their eury-halinity allows to expand the feeding grounds both to the sea and rivers and hunt for both freshwater, anadromous and marine prey. The food spectrum of beluga whales in the Anadyr estuary is very wide and includes 12 fish species and 1 crustacean species. In the summer-autumn season, the salmons are the most significant part of the diet, as chum salmon Oncorhynchus keta , pink salmon O. gorbuscha and arctic char Salvelinus malma , whereas arctic smelt Osmerus mordax dentex , saffron cod Eleginus gracilis , sculpins Cottidae sp., anadyr whitefish Coregonus anaulorum , and siberian whitefish Coregonus sardinella are presented in the diet to a lesser extent. There is supposed on the base of episodic net surveys, that the beluga whales feeding in marine areas is more diverse, and the most important their prey in the sea are walleye pollock Theragra chalcogramma , pacific cod Gadus macrocephalus , flounders Pleuronectidae sp., sculpins Cottidae sp., capelin Mallotus villosus catervarius , polar cod Boreogadus saida , halibuts Pleuronectidae sp., stingrays Bathyraja , herring Clupeidae sp., and several species of decapod crustaceans Hyppolitidae sp. and Lithodidae sp. Natural enemies of beluga whales are killer whale Orcinus orca , polar bear Ursus maritimus , and predatory form of pacific walrus Odobenus rosmarus . Rather large number of beluga whales are eliminated by the sea ice, up to 80 animals annually, that exceeds in several times the aboriginal landings in Chukotka. Parasitic fauna of the beluga whale is still unclear and requires special investigations; the cases of epizooty are unknown in the Anadyr Gulf. Philopatry is proper to the Anadyr beluga whales, with preference of the Anadyr estuary and the Anadyr Gulf as their habitats, that is explained by optimal for them environments and high food capacity. Unique adaptation of beluga whales to the environments of the Anadyr estuary is their ultrasonic vocalization in the high-turbidity waters. Genetic analysis shows a differentiated distribution of the beluga whales haplotypes in different areas of the North Pacific, so the stock of the Anadyr Gulf is significantly isolated in the post-glacial times. Low anthropogenic pressure on beluga whales in the Anadyr Gulf allows them to maintain their stock there.

scholarly journals Genetic profiling links changing sea-ice to shifting beluga whale migration patterns

2016 ◽  
Vol 12 (11) ◽  
pp. 20160404 ◽  
Author(s):  
Greg O'Corry-Crowe ◽  
Andrew R. Mahoney ◽  
Robert Suydam ◽  
Lori Quakenbush ◽  
Alex Whiting ◽  
...  
Keyword(s):  
Sea Ice ◽  
Beluga Whale ◽  
Ocean Dynamics ◽  
Delphinapterus Leucas ◽  
Ecosystem Structure ◽  
Genetic Profiling ◽  
Beluga Whales ◽  
Resource Dispersion ◽  
Ice Conditions ◽  
And Shifts

There is increasing concern over how Arctic fauna will adapt to climate related changes in sea-ice. We used long-term sighting and genetic data on beluga whales ( Delphinapterus leucas ) in conjunction with multi-decadal patterns of sea-ice in the Pacific Arctic to investigate the influence of sea-ice on spring migration and summer residency patterns. Substantial variations in sea-ice conditions were detected across seasons, years and sub-regions, revealing ice–ocean dynamics more complex than Arctic-wide trends suggest. This variation contrasted with a highly consistent pattern of migration and residency by several populations, indicating that belugas can accommodate widely varying sea-ice conditions to perpetuate philopatry to coastal migration destinations. However, a number of anomalous migration and residency events were detected and coincided with anomalous ice years, and in one case with an increase in killer whale ( Orcinus orca ) sightings and reported predation on beluga whales. The behavioural shifts were likely driven by changing sea-ice and associated changes in resource dispersion and predation risk. Continued reductions in sea-ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them.

scholarly journals Results on photo identification for beluga whale Delphinapterus leucas in the Anadyr estuary of the Bering Sea

2014 ◽  
Vol 179 (4) ◽  
pp. 120-128
Author(s):  
Ekaterina A. Prasolova ◽  
Roman A. Belikov ◽  
Andrey A. Ryabov ◽  
Denis I. Litovka
Keyword(s):  
Bering Sea ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Shirshov Institute ◽  
Hunting Behavior ◽  
Beluga Whales ◽  
Photo Identification ◽  
Large Aggregation ◽  
Skin Damages ◽  
Anadyr Estuary

Definition of individual beluga whales by the method of photo identification and selection of the main types of markers are presented for beluga whales in the Anadyr estuary, western Bering Sea. The study was conducted in the aggregation of beluga whales in three different sites at Anadyr - in the Anadyr sea port and at ferry docks № 8 and № 10 in the period from August 14 to September 6, 2013 (summer feeding of the whales). The maximum number of whales (40-70 animals) was observed at the ferry dock № 10, 2-6 whales were at the ferry dock № 8, and 1-2 ones - at the port. Mother-calf pairs were observed in all sites, but the portion of adult whales was the highest at the ferry dock № 10. Photocamera Nikon D90 and Nikkor lens (70-200 mm) were used for the photo ID. Mechanical skin damages, infections, spinal ridge traces, and age spots were used as individual markers. In total, 4400 images were obtained, including 155 ones with sides of beluga whales. The markers were observed both on the left side (32 cases) and right side (97 cases) of the whales, but both sides were identified for 13 whales only, including 3 females with calves. Taking into account the risk of reassessment in case of using two sides for identification, the identification is considered as successful for 110 individuals of beluga whale. Almost all identified individuals were met only once during the whole period of observation, only 6 of them were met twice, and only 4 - three times. One whale appeared 3 days in a row: on August 16, 17 and 18, and 5 individuals came 2 days in a row. Such few recurrent meetings may indicate a weak fidelity of beluga whales to certain water areas in the estuary, though maybe the length of study is insufficient, taking into account that a strong fidelity of mother-calf pairs of beluga whales to certain areas of the Anadyr estuary, considered as their hunting areas, was determined by visual observations of Shirshov Institute of Oceanology in the 1980s. Probably, the area at the dock № 10, where the whales form large aggregation, is not assigned to individual animals but is a common feeding area. This large aggregation is similar to the aggregation of beluga whales at Cape Beluzhy of Solovetsky Island in the White Sea. However, these aggregations are fundamentally different by their nature: the reproductive aggregation at Solovetsky Island is distinguished by various forms of social interactions, including sexual activity, while the search and hunting behavior prevail in the feeding aggregation at the ferry dock № 10. The main reason for the beluga whales concentration in this area is dense concentration of freshwater fish and salmons migrating for spawning. Reproductive aggregations of beluga whales are not known yet in the Far-Eastern Seas.

scholarly journals Reproductive Parameters for Female Beluga Whales (Delphinapterus leucas) of Baffin Bay and Hudson Bay, Canada

ARCTIC ◽  
2020 ◽  
Vol 73 (4) ◽  
pp. 405-420
Author(s):  
Steven H. Ferguson ◽  
Cornelia Willing ◽  
Trish C. Kelley ◽  
David A. Boguski ◽  
David J. Yurkowski ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Growth Patterns ◽  
Beluga Whale ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Reproductive Parameters ◽  
Baffin Bay ◽  
Beluga Whales ◽  
Reproductive Patterns

Monitoring marine mammal populations and their habitats is crucial for assessing population status and defining realistic management and conservation goals. Environmental and anthropogenic changes in the Arctic have prompted the pursuit for improved understanding of female beluga whale (Delphinapterus leucas) spatial and temporal reproductive patterns. There are relatively few estimates for female reproductive parameters of beluga whale populations across the Arctic, and those few that are available are outdated. Here we summarize female reproductive data from samples collected through Inuit subsistence hunts of three eastern Canadian Arctic beluga populations: High Arctic/Baffin Bay (HA), Western Hudson Bay (HB), and Cumberland Sound (CS) from 1989 to 2014. We grouped the CS and HA populations into a Baffin Bay region (BB) population based on similar body growth patterns and genetic similarity. Asymptotic body length of BB beluga whales (370.9 cm) was greater than HB whales (354.4 cm) as established from Gompertz growth curves fitted for whales ranging in age from 1 – 89 y. We did not detect a significant difference in average number of pseudocervices (8.6) between regions. Differences in average age of sexual maturity (ASM) and length at sexual maturity (LSM) were identified, with evidence of BB females maturing earlier than females from HB (probability method BB = 9.9 y versus HB = 11.0 and logistic method ASM50% HB = 9.99 and BB unresolved). BB females were also longer than HB females at maturing age (logistic LSM50%: BB = 314.5 cm vs HB = 290.3). Total corpora counts were strongly correlated with age, although the number of corpora (≥ 10 mm) suggests reproductive senescence between 40 and 50 y. Improved understanding of female reproductive patterns and knowledge of changes in the spatial and temporal timing of reproductive processes are fundamental for effective conservation and sustainable management of beluga whale populations.

scholarly journals Polar cod in jeopardy under the retreating Arctic sea ice

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Mats Brockstedt Olsen Huserbråten ◽  
Elena Eriksen ◽  
Harald Gjøsæter ◽  
Frode Vikebø
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Keystone Species ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Biophysical Model ◽  
The Arctic ◽  
Polar Cod ◽  
Arctic Sea ◽  
Shelf Sea

Abstract The Arctic amplification of global warming is causing the Arctic-Atlantic ice edge to retreat at unprecedented rates. Here we show how variability and change in sea ice cover in the Barents Sea, the largest shelf sea of the Arctic, affect the population dynamics of a keystone species of the ice-associated food web, the polar cod (Boreogadus saida). The data-driven biophysical model of polar cod early life stages assembled here predicts a strong mechanistic link between survival and variation in ice cover and temperature, suggesting imminent recruitment collapse should the observed ice-reduction and heating continue. Backtracking of drifting eggs and larvae from observations also demonstrates a northward retreat of one of two clearly defined spawning assemblages, possibly in response to warming. With annual to decadal ice-predictions under development the mechanistic physical-biological links presented here represent a powerful tool for making long-term predictions for the propagation of polar cod stocks.

scholarly journals The summer soundscape of a shallow-water estuary used by beluga whales in the western Canadian Arctic

2020 ◽  
Vol 6 (4) ◽  
pp. 361-383 ◽  
Author(s):  
William D. Halliday ◽  
Kevin Scharffenberg ◽  
Dustin Whalen ◽  
Shannon A. MacPhee ◽  
Lisa L. Loseto ◽  
...  
Keyword(s):  
Marine Protected Area ◽  
River Estuary ◽  
Canadian Arctic ◽  
Time Of Day ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Marine Animals ◽  
Frequency Bands ◽  
Beluga Whales ◽  
Important Habitat

The soundscape is an important habitat component for marine animals. In the Arctic, marine conditions are changing rapidly due to sea ice loss and increased anthropogenic activities such as shipping, which will influence the soundscape. Here, we assess the contributors to the summer soundscape in the shallow waters of the Mackenzie River estuary within the Tarium Niryutait Marine Protected Area in the western Canadian Arctic, a core summering habitat for beluga whales (Delphinapterus leucas Pallas, 1776). We collected passive acoustic data during the summer over four years, and assessed the influence of physical variables, beluga whale vocalizations, and boat noise on sound pressure levels in three frequency bands (low: 0.2–1 kHz; medium: 1–10 kHz; high: 10–48 kHz) to quantify the soundscape. Wind speed, wave height, beluga vocalizations, and boat noise were all large contributors to the soundscape in various frequency bands. The soundscape varied to a lesser degree between sites, time of day, and with tide height, but remained relatively constant between years. This study is the first detailed description of a shallow summer soundscape in the western Canadian Arctic, an important habitat for beluga whales, and can be used as a baseline to monitor future changes during this season.

scholarly journals Temporal shifts in intraguild predation pressure between beluga whales and Greenland halibut in a changing Arctic

2017 ◽  
Vol 13 (11) ◽  
pp. 20170433 ◽  
Author(s):  
David J. Yurkowski ◽  
Nigel E. Hussey ◽  
Aaron T. Fisk ◽  
Kendra L. Imrie ◽  
Ross F. Tallman ◽  
...  
Keyword(s):  
Intraguild Predation ◽  
Prey Availability ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Forage Fish ◽  
Greenland Halibut ◽  
Predator Species ◽  
Beluga Whales ◽  
Decadal Scale ◽  
Temporal Shifts

Asymmetrical intraguild predation (AIGP), which combines both predation and competition between predator species, is pervasive in nature with relative strengths varying by prey availability. But with species redistributions associated with climate change, the response by endemic predators within an AIGP context to changing biotic–abiotic conditions over time (i.e. seasonal and decadal) has yet to be quantified. Furthermore, little is known on AIGP dynamics in ecosystems undergoing rapid directional change such as the Arctic. Here, we investigate the flexibility of AIGP among two predators in the same trophic guild: beluga ( Delphinapterus leucas ) and Greenland halibut ( Reinhardtius hippoglossoides ), by season and over 30 years in Cumberland Sound—a system where forage fish capelin ( Mallotus villosus ) have recently become more available. Using stable isotopes, we illustrate different predator responses to temporal shifts in forage fish availability. On a seasonal cycle, beluga consumed less Greenland halibut and increased consumption of forage fish during summer, contrasting a constant consumption rate of forage fish by Greenland halibut year-round leading to decreased AIGP pressure between predators. Over a decadal scale (1982–2012), annual consumption of forage fish by beluga increased with a concomitant decline in the consumption of Greenland halibut, thereby indicating decreased AIGP pressure between predators in concordance with increased forage fish availability. The long-term changes of AIGP pressure between endemic predators illustrated here highlights climate-driven environmental alterations to interspecific intraguild interactions in the Arctic.

scholarly journals Vertical sonar beam width and scanning behavior of wild belugas (Delphinapterus leucas) in West Greenland

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257054
Author(s):  
Marie J. Zahn ◽  
Kristin L. Laidre ◽  
Peter Stilz ◽  
Marianne H. Rasmussen ◽  
Jens C. Koblitz
Keyword(s):  
Beam Width ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Recording Equipment ◽  
West Greenland ◽  
Beluga Whales ◽  
Pack Ice ◽  
Scanning Behavior ◽  
Hydrophone Array ◽  
Free Ranging

Echolocation signals of wild beluga whales (Delphinapterus leucas) were recorded in 2013 using a vertical, linear 16-hydrophone array at two locations in the pack ice of Baffin Bay, West Greenland. Individual whales were localized for 4:42 minutes of 1:04 hours of recordings. Clicks centered on the recording equipment (i.e. on-axis clicks) were isolated to calculate sonar parameters. We report the first sonar beam estimate of in situ recordings of wild belugas with an average -3 dB asymmetrical vertical beam width of 5.4°, showing a wider ventral beam. This narrow beam width is consistent with estimates from captive belugas; however, our results indicate that beluga sonar beams may not be symmetrical and may differ in wild and captive contexts. The mean apparent source level for on-axis clicks was 212 dB pp re 1 μPa and whales were shown to vertically scan the array from 120 meters distance. Our findings support the hypothesis that highly directional sonar beams and high source levels are an evolutionary adaptation for Arctic odontocetes to reduce unwanted surface echoes from sea ice (i.e., acoustic clutter) and effectively navigate through leads in the pack ice (e.g., find breathing holes). These results provide the first baseline beluga sonar metrics from free-ranging animals using a hydrophone array and are important for acoustic programs throughout the Arctic, particularly for acoustic classification between belugas and narwhals (Monodon monoceros).

scholarly journals Alaska Beluga Whale Committee—a unique model of co-management

2021 ◽  
Vol 40 ◽  
Author(s):  
Kathryn J. Frost ◽  
Tom Gray ◽  
Willie Goodwin, Sr. ◽  
Roswell Schaeffer ◽  
Robert Suydam
Keyword(s):  
Local Governments ◽  
Cost Effective ◽  
Aerial Survey ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Funding Agency ◽  
Federal State ◽  
Bristol Bay ◽  
Subsistence Hunting ◽  
Beluga Whales

The Alaska Beluga Whale Committe (ABWC) was formed in 1988 to conserve beluga whales (Delphinapterus leucas) and manage beluga subsistence hunting in western and northern Alaska in cooperation with the National Marine Fisheries Service (NMFS). When the ABWC was formed, there was no consistently funded research or management programme for belugas in Alaska, and co-management was a new concept. The ABWC brought together representatives from beluga hunting communities; federal, state, tribal and local governments; and beluga researchers to develop and implement a programme to manage belugas. With funding from NMFS and others, the ABWC has collected data necessary for informed management decisions including the following: harvest data; aerial surveys of belugas in Bristol Bay and the eastern Bering and Chukchi seas; beluga tracking studies, including training hunters to attach transmitters; a pioneering genetics study of beluga stock identity that has facilitated collection of >2000 beluga skin samples; and a genetics-based mark–recapture study to estimate beluga abundance in Bristol Bay and validate aerial survey estimates. The ABWC is currently engaged in regional management planning in Kotzebue Sound and the eastern Bering Sea. It produces results that are scientifically valid, locally accepted and cost-effective and is an example of what can be achieved when Native hunters, scientists and managing agencies respect and listen to one another and work together. However, the current NMFS co-management funding process has fundamentally altered the relationship between NMFS and ABWC, with NMFS now acting more like a funding agency than a partner.

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