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

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.

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

Izvestiya TINRO ◽

10.26428/1606-9919-2014-179-113-119 ◽

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.

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

Polar Research ◽

10.33265/polar.v40.5611 ◽

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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The effect of sea-ice loss on beluga whales (Delphinapterus leucas) in West Greenland

Polar Research ◽

10.1111/j.1751-8369.2009.00142.x ◽

2010 ◽

Vol 29 (2) ◽

pp. 198-208 ◽

Cited By ~ 24

Author(s):

M.P. Heide-Jørgensen ◽

K.L. Laidre ◽

D. Borchers ◽

T.A. Marques ◽

H. Stern ◽

...

Keyword(s):

Sea Ice ◽

Delphinapterus Leucas ◽

West Greenland ◽

Beluga Whales

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Prey selection of polar bears in Foxe Basin, NU, Canada: evidence of dietary flexibility in a specialized predator

Oxford Open Climate Change ◽

10.1093/oxfclm/kgab002 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

M P Galicia ◽

G W Thiemann ◽

M G Dyck ◽

S H Ferguson ◽

I Stirling

Keyword(s):

Sea Ice ◽

Polar Bear ◽

Prey Availability ◽

Bowhead Whale ◽

Food Sources ◽

Foraging Strategies ◽

Delphinapterus Leucas ◽

Polar Bears ◽

Foxe Basin ◽

Ice Conditions

Abstract Ecological flexibility of a species reflects its ability to cope with environmental change. Although polar bears (Ursus maritimus) are experiencing changes in foraging opportunities due to sea ice loss, regional prey availability and environmental conditions will influence the rate and severity of these effects. We examined changes in polar bear diet and the influence of sea ice characteristics in Foxe Basin over an 18-year period. We combined previous fatty acid data from bears harvested from 1999 to 2003 (n = 82) with additional data from 2010 to 2018 (n = 397). Polar bear diets were diverse; however, ringed seal (Pusa hispida) was the primary prey throughout the sample period. Prey contribution varied temporally and spatially, and by intrinsic factors, while the frequency of prey in diets varied over time suggesting that diet estimates reflect the variability in available prey. Bowhead whale (Balaena mysticetus), although still a minor dietary component, has more than doubled in frequency of occurrence in diets in recent years in association with increased scavenging opportunities. Higher dietary levels of beluga whale (Delphinapterus leucas) and harbour seal (Phoca vitulina) were linked to later breakup date suggesting heavier ice conditions may promote access to both prey species. The flexible foraging strategies of bears in Foxe Basin may help mitigate their vulnerability to changes in prey distribution and habitat conditions. Our results provide insights into the importance of alternative and supplemental food sources for polar bears during phenological changes in ice conditions that will likely have consequences to Arctic community structure as warming continues.

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Larger body size leads to greater female beluga whale reproductive activity at the southern periphery of their range

10.22541/au.161885692.23949677/v1 ◽

2021 ◽

Author(s):

Steven Ferguson ◽

David Yurkowski ◽

Justine Hudson ◽

Tera Edkins ◽

Cornelia Willing ◽

...

Keyword(s):

Body Size ◽

Body Length ◽

Reproductive Activity ◽

Food Competition ◽

Beluga Whale ◽

Delphinapterus Leucas ◽

Hudson Bay ◽

Beluga Whales ◽

Future Challenges ◽

Variation Explained

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to reproductive activity (RA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared RA patterns the of the two populations’ with age and body length. Female beluga whale RA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whale accounted for considerably more of the total variation (12 vs 1%) in RA compared to BB whales. We speculate that female HB beluga whale RA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how RA, and potentially fitness, varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

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

Izvestiya TINRO ◽

10.26428/1606-9919-2014-179-120-128 ◽

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.

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

ARCTIC ◽

10.14430/arctic71435 ◽

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.

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Larger body size leads to greater female beluga whale ovarian reproductive activity at the southern periphery of their range

10.22541/au.162602013.36012267/v1 ◽

2021 ◽

Author(s):

Steven Ferguson ◽

David Yurkowski ◽

Justine Hudson ◽

Tera Edkins ◽

Cornelia Willing ◽

...

Keyword(s):

Body Size ◽

Body Length ◽

Reproductive Activity ◽

Food Competition ◽

Beluga Whale ◽

Delphinapterus Leucas ◽

Hudson Bay ◽

Beluga Whales ◽

Future Challenges ◽

Variation Explained

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to ovarian reproductive activity (ORA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared ORA patterns of the two populations with age and body length. Female beluga whale ORA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whales accounted for considerably more of the total variation (12 vs 1%) in ORA compared to BB whales. We speculate that female HB beluga whale ORA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how ORA varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

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