Variability of Arctic Sea Ice: The View from Space, An 18-year Record

Parkinson, Claire L.

doi:10.14430/arctic866

Cited by 94 publications

(48 citation statements)

References 30 publications

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“…The record is now almost 25 years long making it one of the most valuable datasets for use in climate monitoring and other sea ice-climate process studies (Parkinson, 2000). The data are obtained from the Nimbus-7 Scanning Sensor Microwave Radiometer (SMMR) starting in late 1978 until 1987 and from the Special Sensor Microwave/Imager (SSM/I) sensors on the U.S. Defense Military Satellites starting in 1987 to the present.…”

Section: Comparativement à La Série De Cartes Hémisphériques Du Natiomentioning

confidence: 99%

The use of operational ice charts for evaluating passive microwave ice concentration data

Agnew¹,

Howell

2003

Atmosphere-Ocean

113

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Section: Comparativement à La Série De Cartes Hémisphériques Du Natiomentioning

confidence: 99%

The use of operational ice charts for evaluating passive microwave ice concentration data

Agnew¹,

Howell

2003

Atmosphere-Ocean

113

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“…Because bowhead fecundity is probably related to the strength of Calanus production, global warming and climatic perturbations are likely to have an impact on population growth, either negative or positive, through changes in the extent of sea ice. In contrast to other Arctic regions, Baffin Bay has experienced heavier than normal ice seasons in recent decades (Parkinson, 2000), with reduced Calanus production and whale feeding in years of major climatic oscillations (e.g., in 1983Finley et al, 1983, unpubl. data).…”

Section: Climate Changementioning

confidence: 99%

Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic

Finley¹

2001

ARCTIC

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ABSTRACT. One of the longest-living mammals, the Greenland whale or bowhead (Balaena mysticetus) is specialized to filter small crustaceans, especially Calanus copepods, from barren Arctic seas. Brought to near extinction by commercial whaling, the North Atlantic 'meta-population' remains at less than 5% of its former abundance, and none of its three constituent stocks has shown demonstrable recovery during the last century. Two of these stocks, the Baffin Bay and Hudson Bay populations, occur in coastal waters of the Eastern Canadian Arctic during summer. Each of these two stocks numbers in the low hundreds and exists in isolated groups segregated by age and sex, showing strong fidelity to essential habitats. A skewed age distribution, predation by killer whales (Orcinus orca), hunting, net entanglement, tourism, climate change, habitat loss, and inbreeding suppression are some of the factors that may affect the bowhead's recovery. We need local and historical knowledge to understand the bowhead's natural history. Together with scientific data, such knowledge is also useful in evaluating the status of the species and prescribing a management plan. A recovery plan must employ the precautionary principle, both within the international 'meta-population' context and at the sub-population level; it must take a historical view and seek to protect abandoned habitats. Canada has conducted whaling activities that violate international agreements and diminish the effectiveness of the International Whaling Commission.Key words: Greenland whale, bowhead whale, Balaena mysticetus, biology, conservation, management, traditional knowledge RÉSUMÉ. La baleine boréale ou baleine franche (Balaena mysticetus), l'un des mammifères qui vit le plus longtemps, est spécialisée pour filtrer les petits crustacés, des copépodes Calanus pour la plupart, vivant dans les mers arctiques peu peuplées. Amenée au bord de l'extinction par la chasse commerciale à la baleine, la «métapopulation» de l'Atlantique Nord se maintient à moins de 5 p. cent de son abondance passée, et aucun des trois stocks qui la composent n'a montré un rétablissement ferme au cours du siècle dernier. Deux de ces stocks, la population de la baie de Baffin et celle de la baie d'Hudson, se trouvent en été dans les eaux côtières de l'Arctique canadien oriental. Chacun d'eux comprend quelques centaines d'individus, répartis en groupes isolés selon l'âge et le sexe, qui démontrent une fidélité marquée pour les habitats essentiels à leur survie. Une asymétrie de la distribution par âge, la prédation par les épaulards (Orcinus orca), la chasse, l'enchevêtrement dans les filets, le tourisme, le changement climatique, la perte d'habitat et la dépression consanguine sont au nombre des facteurs qui pourraient influencer le rétablissement de l'espèce. Le savoir local et le savoir historique sont tous deux nécessaires pour comprendre l'évolution naturelle de la baleine boréale. Couplés aux données scientifiques, ces savoirs sont en outre utiles dans l'évaluation de l'état de l'espèce ...

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“…Extrinsic factors may also affect predator foraging patterns, and increasing temperatures and declining seaice coverage in many parts of the Arctic (e.g., Callaghan and Jonasson 1995, Parkinson 2000, Comiso 2002 are having significant, yet incompletely understood effects on marine ecosystems (e.g., Gaston et al 2003. Polar bears depend on the sea-ice platform to hunt, and changes in the amount and timing of ice cover may reduce bears' ability to access offshore prey (Stirling et al 1999, Stirling andParkinson 2006), as well as affect the distribution, migration patterns, and reproductive success of those prey (Ferguson et al 2005, Johnston et al 2005.…”

Section: Introductionmentioning

confidence: 99%

Polar Bear Diets and Arctic Marine Food Webs: Insights From Fatty Acid Analysis

Thiemann

Iverson

Stirling³

2008

Ecological Monographs

306

307

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Abstract. We used quantitative fatty acid signature analysis (QFASA) to examine the diets of 1738 individual polar bears (Ursus maritimus) sampled across the Canadian Arctic over a 30-year span. Polar bear foraging varied over large and small spatial and temporal scales, and between demographic groups. Diets in every subpopulation were dominated by ringed seals (Phoca hispida) and, in the eastern Arctic, secondarily by harp seals (Pagophilus groenlandica). Beluga whales (Delphinapterus leucas) were an important food source for bears in the High Arctic, which is consistent with previous anecdotal reports. Foraging patterns were most similar among neighboring subpopulations with similar prey assemblages, but also differed geographically within Western Hudson Bay. The sexual size dimorphism of polar bears had an important effect on foraging, as large bearded seals (Erignathus barbatus) and walruses (Odobenus rosmarus) were consumed most often by older, male bears, whereas ringed seals and, where available, harbor seals (P. vitulina) were most important to younger age classes. Larger, older bears also had the greatest dietary diversity, apparently because of their ability to include larger-bodied prey. During spring and summer, polar bears in some areas increased predation on migratory harp seals and beluga whales. In Western Hudson Bay, bearded seal consumption declined between 1995 and 2001 for both male and female bears and continued to decline among females up to the most recent sampling (2004). Ringed seal consumption in Western Hudson Bay increased between 1998 and 2001, perhaps in response to increased ringed seal productivity, but was not significantly affected by date of sea-ice breakup. Overall, our data indicate that polar bears are capable of opportunistically altering their foraging to take advantage of locally abundant prey, or to some degree compensating for a decline in a dominant prey species. However, in other areas polar bears are dependent on the availability of ringed and bearded seals. Recent population data suggest that polar bears with the most specialized diets may be most vulnerable to climate-related changes in ice conditions. The results of this large-scale, ecosystem-based study indicate a complex relationship between sea-ice conditions, prey population dynamics, and polar bear foraging.

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Variability of Arctic Sea Ice: The View from Space, An 18-year Record

Cited by 94 publications

References 30 publications

The use of operational ice charts for evaluating passive microwave ice concentration data

The use of operational ice charts for evaluating passive microwave ice concentration data

Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic

Polar Bear Diets and Arctic Marine Food Webs: Insights From Fatty Acid Analysis

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