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Caribou, Whales, and Environmental Variability

Caribou, Whales, and Environmental Variability. Craig Nicolson UMass Amherst, Natural Res.Conservation IPY Polar Connections Workshop June 2009. Photo: Craig George. Caribou migration… How do we know where they go?. Photo: Gary Kofinas.

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Caribou, Whales, and Environmental Variability

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  1. Caribou, Whales, and Environmental Variability Craig Nicolson UMass Amherst, Natural Res.Conservation IPY Polar Connections Workshop June 2009 Photo: Craig George

  2. Caribou migration…How do we know where they go?

  3. Photo: Gary Kofinas

  4. Population dynamics…How many caribou are there?Increasing or decreasing?Carrying capacity?

  5. Population dynamics

  6. 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

  7. Compare PCH with other Alaskan herds • Much slower growth rate (lambda) over same time period

  8. Habitat Condition and Caribou Forage • How do we measure habitat quality?? • Large areas • Difficult to estimate forage abundance only with traditional fieldwork • Satellite imagery…

  9. Beaufort Sea Concentrated Calving Annual Calving Ground Extent of Calving 1983-2000

  10. r2 = 0.85 Griffith et al 2003.

  11. 4. Caribou and oil-fields Central Arctic Herd analogy

  12. Two effects: behavior & displacement • altered activity and behavior  higher energy expenditure 2.displacement to poorer forage reduced food intake  less energy greater exposure to predators Impacts of negative energy budget lower probability of calf survival lower probability of conception lower probability of survival of the individual

  13. Effects of Development on Activity (Field study) 50% NoDevelopment 40% High Development 30% Percent Time 20% 10% 0% %Feed %Lie %Stand %Walk %Run Murphy 1998

  14. And now for something… … completely different

  15. 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) 40 ft

  16. Nutepelmen Enurmino Inchoun Uelen Lavrentia Lorino Yanrakinnot Enmelen Sireniki Nuneigran Annual Bowhead Whale migration cycle…

  17. winter • repair boat frame • clothing (parkas) • hunt caribou Fall whaling (open water) D J N O F spring S M • ugruk skin (umiaq) • cover boat • clean ice cellar • cut ice road to camp A A summer J M J • ugruk hunting • meat, skin, oil • motorboat mainten. Spring whaling (ice leads) Whaling is a year-round activity…

  18. Spring hunting • April 20 – May 31 • set up camps on shorefast ice • umiaqs perched on edge • whales swim in ice leads

  19. 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!

  20. 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

  21. 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)

  22. 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

  23. A puzzling question • 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??

  24. What factors affect hunting success? • Craig George & Harry Brower Jr spoke to captains • Four main themes emerged Whale availability Spring hunt Bowhead harvest (Barrow ) Environmental conditions Good quality meat and maktak Quota

  25. Blowing snow Sea smoke Temperature Wind (speed, dir) Rough water Lead width Ice conc. in lead Fog Ocean currents (speed, dir) Lead condition Abrupt sea level change Ice condition (camp, transport) Spring hunt Bowhead harvest (Barrow ) Environmental conditions Multi-year ice Fall freeze-up Quota

  26. Blowing snow Sea smoke Temperature Wind (speed, dir) Rough water Lead width Ice conc. in lead Fog Ocean currents (speed, dir) Lead condition Abrupt sea level change Ice condition (camp, transport) Spring hunt Bowhead harvest (Barrow ) Environmental conditions Multi-year ice Fall freeze-up Quota

  27. What factors affect harvest success? • Wind speed

  28. Wind direction • 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 Apr 20 Apr 21 E W Apr 22 Apr 23, 1997 ESE, 23km/h S

  29. N E W S Spring hunting season in Barrow • April 20 – May 31 • From 1990 to 1997

  30. Look at the wind direction on successful harvest days 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.

  31. 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

  32. 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)

  33. Fall wind vector plot 1990-1997 Spring wind vector plot 1990-1997 Wind conditions in fall

  34. 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…

  35. Mapping activity… • Groups of 2 • Before lunch: • Plot up transect lines • … and sightings on that flight • After lunch • Add in other observations • Compare

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