Population genetic structure of beluga whales (Delphinapterus leucas): mitochondrial DNA sequence variation within and among North American populations

1997 ◽  
Vol 75 (5) ◽  
pp. 795-802 ◽  
Author(s):  
Ree Brennin ◽  
Brent W. Murray ◽  
Bradley N. White ◽  
James W. Clayton ◽  
Margaret K. Friesen ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Structure ◽  
North American ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Genetic Structuring ◽  
Lawrence Estuary ◽  
Beluga Whales ◽  
Western Hudson Bay

Beluga whales (Delphinapterus leucas) are migratory over much of their range, congregating in small groups around shallow river estuaries in summer and overwintering in areas of broken pack ice. To investigate the potential genetic structuring within North American beluga, we analyzed variation in mitochondrial DNA (mtDNA). Using 10 restriction enzymes, eight haplotypes were identified among 95 beluga from 12 sampling locations. The haplotypes formed two lineages, one occurring primarily in whales from the St. Lawrence estuary and eastern Hudson Bay and the other primarily in beluga sampled in the waters of western Hudson Bay, southern Baffin Island, western Greenland, the Canadian High Arctic, and the eastern Beaufort Sea. The genetic difference between these lineages and the high-level genetic structure among the sample locations, [Formula: see text] (p ≤ 0.0001), indicate that these lineages may represent the original Pacific and Atlantic "refugial" stocks that colonized the Arctic after deglaciation. Further, the present segregation of these lineages between populations summering in eastern and western Hudson Bay (p ≤ 0.005) is consistent with the hypothesis that the mitochondria of the beluga summering in western Hudson Bay are descended from those of a Pacific "refugial" stock and those of beluga summering in eastern Hudson Bay are descended from those of an Atlantic "refugial" stock. The clear differentiation of beluga from different summering locations provides evidence for strong maternally directed philopatry to the summering locations.

CYP1A localization in Beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary and the Arctic

2000 ◽  
Vol 50 (1-5) ◽  
pp. 67 ◽  
Author(s):  
J.Y. Wilson ◽  
S.R. Cooke ◽  
M.M. Moore ◽  
D. Martineau ◽  
I. Mikaelian ◽  
...  
Keyword(s):  
The Arctic ◽  
Delphinapterus Leucas ◽  
Lawrence Estuary ◽  
Beluga Whales ◽  
St Lawrence Estuary

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 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 Tumors in St. Lawrence Beluga Whales (Delphinapterus leucas)

1994 ◽  
Vol 31 (4) ◽  
pp. 444-449 ◽  
Author(s):  
S. De Guise ◽  
A. Lagacé ◽  
P. Béland
Keyword(s):  
Small Population ◽  
Delphinapterus Leucas ◽  
Carcinogenic Effect ◽  
Lawrence Estuary ◽  
Beluga Whales ◽  
High Prevalence ◽  
Endangered Population ◽  
High Concentrations ◽  
St Lawrence Estuary ◽  
St Lawrence River

A population of 450–500 belugas ( Delphinapterus leucas) resides in the polluted estuary of the St. Lawrence River. Stranded carcasses of this endangered population were recovered and necropsied. High concentrations of organochlorines, heavy metals, and benzo-a-pyrene exposure were demonstrated in tissues of these whales. Between 1988 and 1990, 21 tumors were found in 12 out of 24 carcasses. Among these tumors, six were malignant and 15 were benign. The animals were between 1.5 and >29 years of age, and the ages of animals with and without tumors did not differ when two juvenile animals (1.5 and 3.5 years of age) were excluded. Seven other neoplasms had been reported previously in six out of 21 well-preserved carcasses examined in the same laboratory between 1982 and 1987. Overall, 28 of the 75 confirmed tumors reported so far in cetaceans (37%) were from this small population of beluga whales in the St. Lawrence Estuary. Such a high prevalence of tumors would suggest an influence of contaminants through a direct carcinogenic effect and/or a decreased resistance to the development of tumors in this population.

Sign in / Sign up

Export Citation Format

Share Document