The State and Future of Mammal Populations in The State and Future of Mammal Populations in the Beaufort Sea and Arctic Oceanthe Beaufort Sea and Arctic Ocean

Polar Bears and Walrus as Sentinels ofPolar Bears and Walrus as Sentinels ofPolar Bears and Walrus as Sentinels of Polar Bears and Walrus as Sentinels of Arctic ChangeArctic Change

Dan James, Chad Jay, Steven Amstrup, and Dave DouglasDan James, Chad Jay, Steven Amstrup, and Dave Douglas, y, p, g, y, p, gU.S. Geological SurveyU.S. Geological Survey

U.S. Department of the InteriorU.S. Geological Survey

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Habitat LossHabitat LossIndustryIndustrySubsistenceSubsistence

TourismTourism

Why polar bears and walrus?y pArctic undergoing rapid change

Both species are symbols of the Arctic

Both species integrate change at lower trophic levels

Both species tightly tied to sea ice – proxies for the status of the arctic ecosystem

Lif Hi tLife History

Atlantic

Pacific walrus

(90% of the

Atlantic walrus

(90% of the world

population)

G l Bi lGeneral Biology

General Biology ...

Life HistoryLife History

RANGE OF POLAR BEARSIN THE POLAR BASIN

RUSSIAIN THE POLAR BASIN

GREENLANDNORTHNORTH POLE

CANADAALASKA

U.S.A

Polar Bears Polar Bears Utilize three Utilize three Ecological Ecological ggStrategiesStrategies

Life history dependence on sea iceLife history dependence on sea ice

••ForagingForaging

••ReproductionReproductionpp

Like all bears, polar bears begin life very small.Like all bears, polar bears begin life very small.

••Females can weigh 800 pounds and males 1400 pounds Females can weigh 800 pounds and males 1400 pounds

P l b li f 30P l b li f 30••Polar bears live for 30 years.Polar bears live for 30 years.

••There are 22,000 There are 22,000 -- 25,000 polar bears in the Arctic.25,000 polar bears in the Arctic.

DiatomsDiatoms

PolarPolarPolarPolarbearbear

ArcticArcticf d h if d h ifood chainfood chain

CopepodsCopepodsArctic codArctic cod

Ringed sealRinged seal

CopepodsCopepods

Research ChallengesResearch Challengesgg

I d t 80% f tiI d t 80% f ti Live on surfaceLive on surfaceIn or under water 80% of timeIn or under water 80% of time Live on surfaceLive on surface

Research ChallengesResearch Challengesgg

t 1997*

Can

ice extent 16 Sept. 1997

Beaufort Sea

Chukchi

Males to land

Russia Alaska Sea

Bering Sea

Females stay with ice

ice extent11 March1997*

WALRUSWALRUSLarge, segregated migrationsLarge, segregated migrations

POLAR BEARSPOLAR BEARSMixed populationsMixed populations

*Source: National I

g , g g gg , g g g p pp p

Research ChallengesResearch Challengesgg

Harder to capture Harder to capture or handleor handle

Easier to capture Easier to capture or handleor handle

Sea Ice, Arctic Climate, andSea Ice, Arctic Climate, andSea Ice, Arctic Climate, and Sea Ice, Arctic Climate, and Wildlife HabitatWildlife Habitat

Al k S i C tU.S. Department of the InteriorU.S. Geological Survey

Alaska Science Center