Bob and Paul go to the Arctic to work with Kit Kovacs, Christian Lydersen, et al. Norwegian Polar Institute, Tromsø, Norway
Impacts are usually projected on a speciesby-species basis Do they have broad ecological tolerances? Are they limited by temperature? (or ph? Or?) General perception is that it will be a major factor, in the future Projections not yet included in Red List process Templates for how to consider CC explicitly are few
Sea ice declining in extent and seasonal duration (much faster than had been projected) Arctic will have ice-free summers within a few decades Arctic temperature change will be much more than in other regions So polar bears won t have ice floes from which to feed
Polar bears feed mostly on ringed seals Ringed seals are getting very little attention Ringed seals keep pups in snow lairs, requiring good snow cover on stable ice Glacier ice calves along shore Pack ice off-shore Requires solid ice to form early enough to accumulate snow before pups are born otherwise fat bears and fox (for now) Ringed seals feed on abundant polar cod under ice margin but only if ice margin is over the continental shelf!
Ringed Seal
Polar cod
Ice cover (with snow) largely absent from Svalbard fjords in recent years Glaciers retreating from coast less calving Recent pup survival about 0% (and bears are fat) Ringed seals mate on maritories patrolled by males around pupping sites Many ringed seals not mating Feeding grounds out on pack ice are nearing the margin of the continental shelf
Walrus
Normally, walrus males stay near shore, while females head out to pack ice to raise pups Both dependent on shallow waters for feeding When walrus females can t get to pack ice (or when it is beyond continental margin) they stay on shore with males to raise their pups Crowding, disturbance among colony leads to trampling of pups (and even females)
Bearded Seal
Alternate food (huge blobs of blubber) for polar bears Raise pups (quickly!) on fast ice at shore edge Bottom feeders like walrus Can t just go north because need to be over the continental shelf to be able to feed
Greenland shark
Little studied, but abundant and Eat seals sleeping on open water, maybe a lot of them So, although seals don t need summer ice for resting spots, they may need ice floes for protection
Bowhead whales Narwhal Beluga Hooded seal Harp seal Cod and other fish stocks
Bowhead whale
Narwhal
Beluga
Hooded Seal
Harp Seal
Bowhead whales Narwhal Beluga Hooded seal Harp seal Cod and other fish stocks The arctic is NOT a simple ecological community! (but it is still simpler than most)
Pack ice extent Distance of pack ice from shore Position relative to continental shelf Glacier calving rate Timing of shore-fast ice formation Snowfall Winter, spring, summer, fall ice Changing water currents and nutrient flows
whales, walrus, bears, seals, sharks are all recovering from former heavy harvest Climate change impacts may be obscured for awhile in simple surveys of numbers
100 90 80 70 60 50 40 Historic N K Future N 30 20 10 0
Ringed seal = Least Concern? Bearded seal = Least Concern? Walrus = Least Concern? Need to look not just at recent distribution, numbers, or even trends But rather at threatening processes and projections
A3. A population size reduction of 80%, projected or suspected to be met within the next 10 years or three generations, B1b. Range Continuing decline, observed, inferred or projected C2. A continuing decline, observed, projected, or inferred, in numbers of mature individuals E. Quantitative analysis showing the probability of extinction in the wild is at least 50% within 10 years or three generations, whichever is the longer (up to a maximum of 100 years).
More southern species are moving in already (not just a future possibility) species that can t live under the ice pack, but can live in the new Arctic Blue whales, humpback whales, killer whales, others Atlantic cod, other more southern fish Harbor seals, grey seals Disease? People! What will be the impacts on the formerly more isolated arctic ice fauna (polar cod, walrus, ringed seals, polar bears, belugas)?
Harbor Seal
Orca
Foraging needs of species Reproduction needs Predator-prey dynamics Energetics Habitat use Dispersal patterns Requirements for ice conditions, and snow conditions at critical times and places Changes are already here!
How the interactions among arctic species will unfold: cascade of impacts Timeline of changes Impacts of newcomers Impacts on local cultures Economic impacts (e.g., on fisheries) Impacts of much increased commercial shipping Impacts of oil and other mineral exploration
Bob, Paul, Kit, and Christian continue to work via email to develop good species models conceptual representations of linkages among species, ice, and snow obtain projections for regional climate changes ice projections from Nat. Snow & Ice Data Center Gather small group back in Tromsø in March to refine parameters and test metamodels (funding from Norwegian Polar Institute) Larger workshop with stakeholders (in fall?) (funding from Arctic Council) to examine projections and test scenarios
Software and draft manual available at www.vortex10.org Concept paper is in press in PLOS ONE
Simple 2-species dynamics To be developed and extended!
Global Warming O c e a n c u r r e n t s People Whales Cod, capelin Ringed seal Polar cod Polar bear Walrus Molluscs Sharks S n o w f a l l Sea ph, salinity, nutrients
Demonstration of major impacts of CC already occurring, with much more to come Template for analyses of impacts in other regions of the Arctic (different time courses) Showcase the kinds of effects that will soon hit many more systems Case for proactive consideration of climate change in Red List process, with methodology for doing so (Pinniped SG is very eager!)
We have the methodology to look at species interactions, impacts of climate change, disease, etc. Concepts and methods being disseminated Methods being applied But it is hard to get the information on specific mechanisms! We are making the links to key experts and groups who have the data and the needs We are ready to lead IUCN and authorities