Estimating abundance of Eastern Canada-West Greenland bowhead whales using genetic mark-recapture analyses

Biddlecombe, Brooke A.; Ferguson, Steve; Heide‐Jørgensen, Mads Peter; Gillis, Darren M.; Watt, Cortney A.

doi:10.1016/j.gecco.2023.e02524

Cited by 3 publications

(2 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dramatic decline between previous and current N e in bowhead whales could have implications for their genetic health, adaptive potential, and management actions. Although bowhead whale census numbers have increased after commercial whaling ceased, there is evidence it may be plateauing below the pre-commercial whaling carrying capacity estimate [62]. Additionally, populations experience drift at their N e and the recovery of genetic diversity will lag behind the recovery of alleles.…”

Section: Discussionmentioning

confidence: 99%

Unraveling the genetic legacy of commercial whaling in bowhead whales and narwhals

de Greef,

Müller,

Thorstensen

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

Commercial whaling decimated many whale populations over several centuries. Bowhead whales (Balaena mysticetus) and narwhal (Monodon monoceros) have similar habitat requirements and are often seen together in the Canadian Arctic. Although their ranges overlap extensively, bowhead whales experienced significantly greater whaling pressure than narwhals. The different harvest histories but similar habitat requirements of these two species provide an opportunity to examine the demographic and genetic consequences of commercial whaling. We whole-genome resequenced Canadian Arctic bowhead whales and narwhals to delineate population structure and reconstruct demographic history. Bowhead whale effective population size sharply declined contemporaneously with the intense commercial whaling period. Narwhals instead exhibited recent growth in effective population size, reflecting limited opportunistic commercial harvest. Although the genetic diversity of bowhead whales and narwhals was similar, bowhead whales had more genetic diversity prior to commercial whaling and will likely continue to experience significant genetic drift in the future. In contrast, narwhals appear to have had long-term low genetic diversity and may not be at imminent risk of the consequences of the erosion of genetic diversity. This work highlights the importance of considering population trajectories in addition to genetic diversity when assessing the genetics of populations for conservation and management purposes.

show abstract

Section: Discussionmentioning

confidence: 99%

Unraveling the genetic legacy of commercial whaling in bowhead whales and narwhals

de Greef,

Müller,

Thorstensen

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The 'East Greenland Svalbard Barents Sea' stock numbered in excess of 52,500 bowhead individuals prior to whaling 9 . Contemporary bowhead whales in the region number some few hundred individuals 9,44 , suggesting a >98% population size decline. In contrast, the pre-whaling estimates for the 'East Canada West Greenland' stock is ~18,500 individuals 45 , and the current population numbers ~6,000 individuals 46 , equivalent to ~70% population size decline.…”

Section: The Genomic Impacts Of Commercial Whalingmentioning

confidence: 99%

Four centuries of commercial whaling eroded 11,000 years of population stability in bowhead whales

Westbury,

Brown,

Cabrera

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

The bowhead whale, an Arctic endemic, was heavily overexploited during commercial whaling between the 16th-20th centuries. Current climate warming, with Arctic amplification of average global temperatures, poses a new threat to the species. Assessing the vulnerability of bowhead whales to near-future predictions of climate change remains challenging, due to lacking data on population dynamics prior to commercial whaling and responses to past climatic change. Here, we integrate palaeogenomics and stable isotope (d13C and d15N) analysis of 201 bowhead whale fossils from the Atlantic Arctic with palaeoclimate and ecological modelling based on 823 radiocarbon dated fossils, 151 of which are new to this study. We find long-term resilience of bowhead whales to Holocene environmental perturbations, with no obvious changes in genetic diversity or population structure, despite large environmental shifts and centuries of whaling by Indigenous peoples prior to commercial harvests. Leveraging our empirical data, we simulated a time-series model to quantify population losses associated with commercial whaling. Our results indicate that commercial exploitation induced population subdivision and losses of genetic diversity that are yet to be fully realised; declines in genetic diversity will continue, even without future population size reductions, compromising the species' resilience to near-future predictions of Arctic warming.

show abstract

Unraveling the Genetic Legacy of Commercial Whaling and Population Dynamics in Arctic Bowhead Whales and Narwhals

de Greef,

Müller,

Thorstensen

et al. 2024

Global Change Biology

View full text Add to dashboard Cite

Assessing genetic structure and diversity in wildlife is particularly important in the context of climate change. The Arctic is rapidly warming, and endemic species must adapt quickly or face significant threats to persistence. Bowhead whales (Balaena mysticetus) and narwhals (Monodon monoceros) are two long‐lived Arctic species with similar habitat requirements and are often seen together in the Canadian Arctic. Although their ranges overlap extensively, bowhead whales experienced significantly greater commercial whaling mortality than narwhals over several centuries. The similar habitat requirements but different harvest histories of these two species provide an opportunity to examine present‐day genetic diversity and the demographic and genetic consequences of commercial whaling. We whole‐genome resequenced contemporary Canadian Arctic bowhead whales and narwhals to delineate population structure and reconstruct demographic history. We found higher genetic diversity in bowhead whales compared to narwhals. However, bowhead whale effective population size sharply declined contemporaneously with the intense commercial whaling period. Narwhals, in contrast, exhibited recent growth in effective population size, likely reflecting exposure to limited opportunistic commercial harvest. Bowhead whales will likely continue to experience significant genetic drift in the future, leading to the erosion of genetic diversity. In contrast, narwhals do not seem to be at imminent risk of losing their current levels of genetic variation due to their long‐term low effective population size and lack of evidence for a recent decline. This work highlights the importance of considering population trajectories in addition to genetic diversity when assessing the genetics of populations for conservation and management purposes.

show abstract

Estimating abundance of Eastern Canada-West Greenland bowhead whales using genetic mark-recapture analyses

Cited by 3 publications

References 29 publications

Unraveling the genetic legacy of commercial whaling in bowhead whales and narwhals

Unraveling the genetic legacy of commercial whaling in bowhead whales and narwhals

Four centuries of commercial whaling eroded 11,000 years of population stability in bowhead whales

Unraveling the Genetic Legacy of Commercial Whaling and Population Dynamics in Arctic Bowhead Whales and Narwhals

Contact Info

Product

Resources

About