Caribou, Whales, and Environmental Variability

Craig NicolsonUMass Amherst, Natural Res.Conservation

IPY Polar Connections Workshop

June 2009Photo: Craig George

Caribou migration…

How do we know where they go?

Photo: Gary Kofinas

Population dynamics…

How many caribou are there?Increasing or decreasing?Carrying capacity?

Population dynamics

Porcupine Caribou Herd Size

140000

178000

160000

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129000

165000

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123000

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1953 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003

# of caribou

Porcupine Caribou calf ratios

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1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

calves:100 cowsBirth rateJuly calf:cow

March calf:cow

• Birth rates aren’t declining in an obvious way• Calf survival rates don’t account for the decline• Computer models show high sensitivity to adult survival rates

Compare PCH with other Alaskan herds

• Much slower growth rate (lambda) over same time period

Habitat Condition and Caribou Forage

How do we measure habitat quality??

Large areas Difficult to estimate forage abundance

only with traditional fieldwork Satellite imagery…

Beaufort Sea

Extent of Calving 1983-2000

Annual Calving Ground

Concentrated Calving

r2 = 0.85

Griffith et al 2003.

4. Caribou and oil-fieldsCentral Arctic Herd analogy

Two effects: behavior & displacement

1. altered activity and behavior higher energy expenditure

2. displacement to poorer foragereduced food intake less energygreater exposure to predators

Impacts of negative energy budget lower probability of calf survival lower probability of conceptionlower probability of survival of the individual

Effects of Development on Activity(Field study)

Effects of Development on Activity(Field study)

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%Feed%Feed%Feed%Feed %Lie%Lie%Lie%Lie %Stand%Stand%Stand%Stand %Walk%Walk%Walk%Walk %Run%Run%Run%Run

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Murphy 1998

And now for something…

… completely different

                                                                                                            

                              

40 ft

Icebreaking Skull (bow…)

Blubber layer 2 ft thick

(floating thermos flask)

Eat around 1,800 kg of plankton / day

Weigh up to 60 tons

(tongue alone weighs 900 kg)

Enurmino

InchounUelen

Lavrentia

Yanrakinnot

SirenikiEnmelenNuneigran

Nutepelmen

Lorino

Annual Bowhead Whale migration cycle…

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Spring whaling (ice leads)

Fall whaling (open water)

winter• repair boat frame• clothing (parkas)• hunt caribou

spring• ugruk skin (umiaq)• cover boat• clean ice cellar• cut ice road to campsummer

• ugruk hunting• meat, skin, oil• motorboat mainten.

Whaling is a year-round activity…

Spring hunting April 20 – May 31

– set up camps on shorefast ice – umiaqs perched on edge– whales swim in ice leads

Fall hunting Sep 1 – Oct 15

– early at Kaktovik (Sep 1 – 15)– later at Barrow (Sep 10 – Oct 20)– whales migrating west and feeding at plankton ‘hotspots’– hunting done in open water before sea freezes over– motorized boats, hunt collectively and tow back to shore– BIG job!

The Institutional Context Whaling crews: husband/wife, co-captain, 10-15

Barrow Whaling Captains’ Association (BWCA)– Community leaders: Elders– Decide collectively on local best practice for whaling

International Whaling Commission– 1946: Intl’ Convention for the Regulation of Whaling– Purpose: conservation of whale stocks whaling industry– 60 member nations

Alaska Eskimo Whaling Commission– Created in 1978; 10 commissioners (locally elected)– Divide the IWC quota between villages– Keep track of inter-village quota transfers

Policy Context/History (IWC) Aboriginal subsistence whaling is seen as being

different to commercial whaling

Three goals:– Ensure risks of extinction not seriously increased – Enable harvests for cultural and nutritional requirements;– Maintain stocks at highest net recruitment level and if below

that ensure they move towards it.

1977: scientific stock assessment 1,300 whales– IWC banned all harvest until NOAA had better numbers– AEWC formed, argued successfully for a small quota (1978)– North Slope Borough Wildlife Management Dept– Gradually increased quota from 18 (1978) to 70 (today)

The Cultural Context “We have developed a kindred relationship with this

great animal. We have a familiarity with the whale that no other people has…” – George Ahmaogak

“Iñupiaq food is social food” - Fanny Akpik

The whale’s gift…– “the bowhead is a very distinguished animal. It can give

itself up, which can make it very easy for the captain and crew, or it can withhold itself from another captain and crew and be struck and lost” - Ida Koonik

– Ice cellars: must be cleaned, prepared, meat shared– Words are important– “When you hunt in harmony, you don’t have trouble

catching the animals”

…how this research began

Whales are essential to culture & subsistence The demand for meat is constant year to year. Effort put into hunting is roughly the same year to year So then…

…why does whale harvest vary so much??

A puzzling question

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1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Whales Landed at Barrow in Spring

Spring hunt Bowhead harvest

(Barrow )

Environmental conditions

Whale availability

Good quality meat and maktak

Quota

What factors affect hunting success?

– Craig George & Harry Brower Jr spoke to captains

– Four main themes emerged

Lead condition

Ice condition (camp, transport)Environmental

conditions

Ice conc. in lead

Rough water

Lead widthFog

Fall freeze-up

TemperatureBlowing

snowSea smoke

Wind (speed, dir)

Multi-year ice

Ocean currents (speed, dir)

Abrupt sea level change

Spring hunt Bowhead harvest

(Barrow )

Quota

Lead condition

Ice condition (camp, transport)Environmental

conditions

Ice conc. in lead

Rough water

Lead widthFog

Fall freeze-up

TemperatureBlowing

snowSea smoke

Wind (speed, dir)

Multi-year ice

Ocean currents (speed, dir)

Abrupt sea level change

Spring hunt Bowhead harvest

(Barrow )

Quota

What factors affect harvest success?

Wind speed

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Daily average wind speed (km/h)

Frequency

All days

Harvest days

Spring daily wind speed in Barrow

Wind direction

Daily wind speed and direction(Vector plot)

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Wind speed from east (km/hr)

Wind speed from north (km/hr)

We have daily wind data for Barrow airport…

Plot each day’s average wind conditions on a vector plot to show both speed and direction…

N

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Apr 20

Apr 23, 1997ESE, 23km/h

Apr 22

Apr 21

Spring hunting season in Barrow April 20 – May 31 From 1990 to 1997

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Look at the wind direction on successful harvest days

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All days

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Red dots: days with whale harvest

Note how winds are almost always from the east when whales are taken in spring (east winds open the ice lead).

Scientific and quantified representation of the captains’ understanding of effect of wind.

Climate strongly impacts spring hunting…

Policy Implications – International Whaling Commission– Subsistence quota may be reduced if it is not used– This shows that there may be good reasons why whale

harvest is low in some years: not a function of need

y = 0.0794e0.049x

R2 = 0.9602

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'Good wind' day weighted index (Apr-20 to May31)

% of quota filled

Fall whaling hypotheses… Driven by quota: they get ‘x’ in spring, and

then in the fall they make up the balance of the annual quota (Q-x)

Wind, ocean, ice conditions

Whale migration patterns– Distance offshore (ice, oil activity)– Timing (stop to feed, ice could come in)

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Wind speed (km/h)

Harvest days

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Fall wind speed frequency distribution

Spring wind vector plot 1990-1997

Fall wind vector plot 1990-1997

Wind conditions in fall

Bowhead Migration Fall hunt

– Minerals Management Service: BWASP– Fall aerial surveys, 1987-2005– Sighting locations by date and # seen– Need to correct for flight transect effort

Migration is affected by sea ice…

Mapping activity…

Groups of 2 Before lunch:

– Plot up transect lines– … and sightings on that flight

After lunch– Add in other observations– Compare