Long-term Trends in the Population Ecology of Polar Bears in Western Hudson Bay in Relation to Climatic Change

Stirling, Ian; Lunn, Nicholas J.; Iacozza, John

doi:10.14430/arctic935

Cited by 431 publications

(565 citation statements)

References 31 publications

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“…Stirling et al (1999) observe that the loss of stable ice flows linked to climate warming are the major factor contributing to Hudson Bay polar bears coming ashore for several months of fasting in progressively poorer condition. Hudson Bay polar bears prey primarily on ringed seals (Phoca hispida), the population of which is in decline due to a loss of these stable ice flows (Furnell and Schweinsburg, 1984;Ramsay and Stirling, 1982;Stirling et al, 1999). Polar bears near starvation will use stored fat as an energy source, remobilizing POPs sequestered in these tissues and potentially resulting in the dual stresses of starvation and chemical toxicity (Macdonald et al, 2005).…”

Section: Altered Ecosystemsmentioning

confidence: 98%

“…▪ Pollutant-exposed ectotherms and species at the edge of their physiological tolerance range may be especially sensitive to temperature increases. Altered environmental salinity ▪ ↓ solubility and ↑ bioavailability of pesticides/POPs ("salting out effect") ( Fortin et al, 2008;Heugens et al, 2001;Moore et al, 2003;Schiedek et al, 2007;Schlenk and El-Alfy, 1998;Schwarzenbach et al, 2003;Song and Brown, 1998;Tachikawa and Sawamura, 1994;Wang et al, 2001;Waring and Moore, 2004) ▪ ↑ salinity + ↑ POP/pesticide exposure may alter osmoregulation due to altered enzymatic pathways Altered ecosystems ▪ Altered POP sequestration and/or remobilization through shifts in food sources and starvation events (AMAP, 2004;Braune et al, 2005;Furnell and Schweinsburg, 1984;Jenssen, 2006;Macdonald et al, 2005Macdonald et al, , 2003Olafsdottir et al, 1998;Ramsay and Stirling, 1982;Schiedek et al, 2007, Stirling et al, 1999) ▪ Shifts in disease vector range and severity coupled with toxicant exposure inhibiting immune response may leave wildlife more susceptible to disease ▪ Low level exposures may impair organism acclimation to ecosystem alterations induced by climate change ▪ Climate change induced changes in trophic food webs may alter POP bioaccumulation and biomagnification mykiss) exposed to the insecticide endosulfan as temperature was increased from 13°C to 16°C. In contrast to these findings, pyrethroids and DDT are generally thought to be more toxic under low temperature conditions, which may be due to a sodium channel modulated increase in nervous system vulnerability at lower temperatures (Narahashi, 2000).…”

Section: Relationships/interactions Referencesmentioning

confidence: 99%

“…Climate change producing alterations in trophic structures, food sources, migratory patterns, and feeding behavior may influence processes of bioaccumulation and biomagnification in POP-exposed animals (AMAP, 2004;Furnell and Schweinsburg, 1984;Macdonald et al, 2005;Olafsdottir et al, 1998;Ramsay and Stirling, 1982;Stirling et al, 1999). Important solvent switching and solvent depletion processes involve the partitioning of POPs from water to phytoplankton and zooplankton at the base of aquatic food chains followed by bioaccumulation and biomagnification up the food chain (Braune et al, 2005;Macdonald et al, 2005).…”

Section: Altered Ecosystemsmentioning

confidence: 99%

“…For example, polar bears (Ursus maritimus) generally have the highest concentrations of POPs of any Arctic animal (Braune et al, 2005). Stirling et al (1999) observe that the loss of stable ice flows linked to climate warming are the major factor contributing to Hudson Bay polar bears coming ashore for several months of fasting in progressively poorer condition. Hudson Bay polar bears prey primarily on ringed seals (Phoca hispida), the population of which is in decline due to a loss of these stable ice flows (Furnell and Schweinsburg, 1984;Ramsay and Stirling, 1982;Stirling et al, 1999).…”

Section: Altered Ecosystemsmentioning

confidence: 99%

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The toxicology of climate change: Environmental contaminants in a warming world

Noyes

McElwee

Miller

et al. 2009

Environment International

938

569

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Climate change induced by anthropogenic warming of the earth's atmosphere is a daunting problem. This review examines one of the consequences of climate change that has only recently attracted attention: namely, the effects of climate change on the environmental distribution and toxicity of chemical pollutants. A review was undertaken of the scientific literature (original research articles, reviews, government and intergovernmental reports) focusing on the interactions of toxicants with the environmental parameters, temperature, precipitation, and salinity, as altered by climate change. Three broad classes of chemical toxicants of global significance were the focus: air pollutants, persistent organic pollutants (POPs), including some organochlorine pesticides, and other classes of pesticides. Generally, increases in temperature will enhance the toxicity of contaminants and increase concentrations of tropospheric ozone regionally, but will also likely increase rates of chemical degradation. While further research is needed, climate change coupled with air pollutant exposures may have potentially serious adverse consequences for human health in urban and polluted regions. Climate change producing alterations in: food webs, lipid dynamics, ice and snow melt, and organic carbon cycling could result in increased POP levels in water, soil, and biota. There is also compelling evidence that increasing temperatures could be deleterious to pollutant-exposed wildlife. For example, elevated water temperatures may alter the biotransformation of contaminants to more bioactive metabolites and impair homeostasis. The complex interactions between climate change and pollutants may be particularly problematic for species living at the edge of their physiological tolerance range where acclimation capacity may be limited. In addition to temperature increases, regional precipitation patterns are projected to be altered with climate change. Regions subject to decreases in precipitation may experience enhanced volatilization of POPs and pesticides to the atmosphere. Reduced precipitation will also increase air pollution in urbanized regions resulting in negative health effects, which may be exacerbated by temperature increases. Regions subject to increased precipitation will have lower levels of air pollution, but will likely experience enhanced surface deposition of airborne POPs and increased run-off of pesticides. Moreover, increases in the intensity and frequency of storm events linked to climate change could lead to more severe episodes of chemical contamination of water bodies and surrounding watersheds. Changes in salinity may affect aquatic organisms as an independent stressor as well as by altering the bioavailability and in some instances increasing the toxicity of chemicals. A paramount issue will be to identify species and populations especially vulnerable to climate-pollutant interactions, in the context of the many other physical, chemical, and biological stressors that will be altered with climate change. Moreover, it w...

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Section: Altered Ecosystemsmentioning

confidence: 98%

Section: Relationships/interactions Referencesmentioning

confidence: 99%

Section: Altered Ecosystemsmentioning

confidence: 99%

Section: Altered Ecosystemsmentioning

confidence: 99%

See 2 more Smart Citations

The toxicology of climate change: Environmental contaminants in a warming world

Noyes

McElwee

Miller

et al. 2009

Environment International

938

569

View full text Add to dashboard Cite

show abstract

“…P olar bears (Ursus maritimus) are highly dependent on Arctic sea ice, and recent declines in sea ice availability have been associated with reduced body condition, reproduction, survival, and population size for polar bears in parts of their range (Stirling et al 1999, Obbard et al 2006, Stirling and Parkinson 2006, Regehr et al 2007a. Observed sea ice declines (Maslanik et al 1996, Overpeck et al 2005 Interfaces 39(4), pp.…”

mentioning

confidence: 99%

Rebuttal of “Polar Bear Population Forecasts: A Public-Policy Forecasting Audit”

et al. 2009

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Observed declines in the Arctic sea ice have resulted in a variety of negative effects on polar bears (Ursus maritimus). Projections for additional future declines in sea ice resulted in a proposal to list polar bears as a threatened species under the United States Endangered Species Act. To provide information for the Department of the Interior's listing-decision process, the US Geological Survey (USGS) produced a series of nine research reports evaluating the present and future status of polar bears throughout their range. In response, Armstrong et al. [Armstrong, J. S., K. C. Green, W. Soon. 2008. Polar bear population forecasts: A public-policy forecasting audit. Interfaces 38(5) 382–405], which we will refer to as AGS, performed an audit of two of these nine reports. AGS claimed that the general circulation models upon which the USGS reports relied were not valid forecasting tools, that USGS researchers were not objective or lacked independence from policy decisions, that they did not utilize all available information in constructing their forecasts, and that they violated numerous principles of forecasting espoused by AGS. AGS (p. 382) concluded that the two USGS reports were “unscientific and inconsequential to decision makers.” We evaluate the AGS audit and show how AGS are mistaken or misleading on every claim. We provide evidence that general circulation models are useful in forecasting future climate conditions and that corporate and government leaders are relying on these models to do so. We clarify the strict independence of the USGS from the listing decision. We show that the allegations of failure to follow the principles of forecasting espoused by AGS are either incorrect or are based on misconceptions about the Arctic environment, polar bear biology, or statistical and mathematical methods. We conclude by showing that the AGS principles of forecasting are too ambiguous and subjective to be used as a reliable basis for auditing scientific investigations. In summary, we show that the AGS audit offers no valid criticism of the USGS conclusion that global warming poses a serious threat to the future welfare of polar bears and that it only serves to distract from reasoned public-policy debate.

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Sea Ice: A Critical Habitat for Polar Marine Mammals and Birds

Haas¹

2003

Sea Ice

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Long-term Trends in the Population Ecology of Polar Bears in Western Hudson Bay in Relation to Climatic Change

Cited by 431 publications

References 31 publications

The toxicology of climate change: Environmental contaminants in a warming world

The toxicology of climate change: Environmental contaminants in a warming world

Rebuttal of “Polar Bear Population Forecasts: A Public-Policy Forecasting Audit”

Sea Ice: A Critical Habitat for Polar Marine Mammals and Birds

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