Changing Sea Ice Conditions in Hudson Bay, 1980–2005

Hochheim, Klaus P.; Barber, David G.; Lukovich, Jennifer V.

doi:10.1007/978-90-481-9121-5_2

Cited by 32 publications

(21 citation statements)

References 22 publications

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“…The Hudson Bay marine ecosystem has experienced physical (e.g., Gagnon and Gough , Hochheim et al. ) and biological (e.g., Stirling et al. , Ferguson et al.…”

Section: Discussionmentioning

confidence: 99%

“…) is a relatively shallow inland sea that is ice‐covered in winter and ice‐free in summer (Hochheim et al. ). Based on extensive capture and harvest records of marked bears (Stirling et al.…”

Section: Methodsmentioning

confidence: 99%

“…Increasing spring temperatures in the region have resulted in trends toward earlier sea ice break‐up and later freeze‐up (Gagnon and Gough , Stirling and Parkinson , Hochheim et al. ), forcing WH polar bears to spend progressively longer periods on land (Cherry et al. ).…”

Section: Introductionmentioning

confidence: 99%

“…The Western Hudson Bay (WH) subpopulation occurs near the southern limit of the species' range (PBSG [IUCN/SSC Polar Bear Specialist Group] 2015). Increasing spring temperatures in the region have resulted in trends toward earlier sea ice break-up and later freeze-up (Gagnon and Gough 2005, Stirling and Parkinson 2006, Hochheim et al 2010, forcing WH polar bears to spend progressively longer periods on land (Cherry et al 2013). Longer ice-free periods have been linked to declines in body condition, reproduction, survival, and abundance (Derocher and Stirling 1995, Stirling et al 1999).…”

Section: Introductionmentioning

confidence: 99%

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Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay

Lunn

Servanty

Regehr

et al. 2016

Ecological Applications

166

158

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Changes in the abundance and distribution of wildlife populations are common consequences of historic and contemporary climate change. Some Arctic marine mammals, such as the polar bear (Ursus maritimus), may be particularly vulnerable to such changes due to the loss of Arctic sea ice. We evaluated the impacts of environmental variation on demographic rates for the Western Hudson Bay (WH), polar bear subpopulation from 1984 to 2011 using live-recapture and dead-recovery data in a Bayesian implementation of multistate capture-recapture models. We found that survival of female polar bears was related to the annual timing of sea ice break-up and formation. Using estimated vital rates (e.g., survival and reproduction) in matrix projection models, we calculated the growth rate of the WH subpopulation and projected population responses under different environmental scenarios while accounting for parametric uncertainty, temporal variation, and demographic stochasticity. Our analysis suggested a long-term decline in the number of bears from 1185 (95% Bayesian credible interval [BCI] = 993-1411) in 1987 to 806 (95% BCI = 653-984) in 2011. In the last 10 yr of the study, the number of bears appeared stable due to temporary stability in sea ice conditions (mean population growth rate for the period 2001-2010 = 1.02, 95% BCI = 0.98-1.06). Looking forward, we estimated long-term growth rates for the WH subpopulation of ~1.02 (95% BCI = 1.00-1.05) and 0.97 (95% BCI = 0.92-1.01) under hypothetical high and low sea ice conditions, respectively. Our findings support previous evidence for a demographic linkage between sea ice conditions and polar bear population dynamics. Furthermore, we present a robust framework for sensitivity analysis with respect to continued climate change (e.g., to inform scenario planning) and for evaluating the combined effects of climate change and management actions on the status of wildlife populations.

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“…The Hudson Bay marine ecosystem has experienced physical (e.g., Gagnon and Gough , Hochheim et al. ) and biological (e.g., Stirling et al. , Ferguson et al.…”

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay

Lunn

Servanty

Regehr

et al. 2016

Ecological Applications

166

158

View full text Add to dashboard Cite

show abstract

“…• Sources: Hochheim, Barber, and Lukovich (2010);Canadian Coast Guard (2012 • There is significant correlation between fall surface air temperatures and both freeze-up dates and late-fall sea ice extent. Variation in spring sea ice extent and breakup dates are linked with fall and spring surface air temperatures and spring wind strengths ).…”

Section: B Sea Ice V Trends and Variabilitymentioning

confidence: 99%

Climate Change in the Hudson Bay Complex: Opportunities and Vulnerabilities for the Port of Churchill's Marine Operations

Andrews¹,

Babb²,

McKernan³

et al.

Climate Change in the Hudson Bay Complex: Opportunities and Vulnerabilities for the Port of Churchill's Marine Operations

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Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator

Galicia

Thiemann

Dyck

et al. 2016

Ecology and Evolution

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Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability. Adipose tissue samples were collected from 103 polar bears harvested during 2010–2012. Polar bear diet composition varied spatially within the region with ringed seal (Pusa hispida) comprising the primary prey in northern and southern Foxe Basin, whereas polar bears in Hudson Strait consumed equal proportions of ringed seal and harp seal (Pagophilus groenlandicus). Walrus (Odobenus rosmarus) consumption was highest in northern Foxe Basin, a trend driven by the ability of adult male bears to capture large‐bodied prey. Importantly, bowhead whale (Balaena mysticetus) contributed to polar bear diets in all areas and all age and sex classes. Bowhead carcasses resulting from killer whale (Orcinus orca) predation and subsistence harvest potentially provide an important supplementary food source for polar bears during the ice‐free period. Our results suggest that the increasing abundance of killer whales and bowhead whales in the region could be indirectly contributing to improved polar bear foraging success despite declining sea ice habitat. However, this indirect interaction between top predators may be temporary if continued sea ice declines eventually severely limit on‐ice feeding opportunities for polar bears.

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Changing Sea Ice Conditions in Hudson Bay, 1980–2005

Cited by 32 publications

References 22 publications

Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay

Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay

Climate Change in the Hudson Bay Complex: Opportunities and Vulnerabilities for the Port of Churchill's Marine Operations

Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator

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