Campus Map

Kristin Laidre

Principal Oceanographer

Assistant Professor, Fisheries





Department Affiliation

Polar Science Center


B.S. Zoology, University of Washington - Seattle, 1999

Ph.D. Aquatic & Fishery Sciences, University of Washington - Seattle, 2003

Kristin Laidre's Website



2000-present and while at APL-UW

Accelerated sea ice loss in the Wandel Sea points to a change in the Arctic's Last Ice Area

Schweiger, A.J., M. Steele, J. Zhang, G.W.K. Moore, and K.L. Laidre, "Accelerated sea ice loss in the Wandel Sea points to a change in the Arctic's Last Ice Area," Comm. Earth Environ., 2, doi:, 2021.

More Info

1 Jul 2021

The Arctic Ocean's Wandel Sea is the easternmost sector of the Last Ice Area, where thick, old sea ice is expected to endure longer than elsewhere. Nevertheless, in August 2020 the area experienced record-low sea ice concentration. Here we use satellite data and sea ice model experiments to determine what caused this record sea ice minimum. In our simulations there was a multi-year sea-ice thinning trend due to climate change. Natural climate variability expressed as wind-forced ice advection and subsequent melt added to this trend. In spring 2020, the Wandel Sea had a mixture of both thin and — unusual for recent years — thick ice, but this thick ice was not sufficiently widespread to prevent the summer sea ice concentration minimum. With continued thinning, more frequent low summer sea ice events are expected. We suggest that the Last Ice Area, an important refuge for ice-dependent species, is less resilient to warming than previously thought.

Do wild polar bears (Ursus maritimus) use tools when hunting walruses (Odobenus rosmarus)?

Stirling, I., K.L. Laidre, and E.W. Born, "Do wild polar bears (Ursus maritimus) use tools when hunting walruses (Odobenus rosmarus)?" Arctic, 74, 175-187, doi:10.14430/arctic72532, 2021.

More Info

8 Jun 2021

Since the late 1700s, reports of polar bears (Ursus maritimus) using tools (i.e., pieces of ice or stones) to kill walruses (Odobenus rosmarus) have been passed on verbally to explorers and naturalists by their Inuit guides, based on local traditional ecological knowledge (TEK) as well as accounts of direct observations or interpretations of tracks in the snow made by the Inuit hunters who reported them. To assess the possibility that polar bears may occasionally use tools to hunt walruses in the wild, we summarize 1) observations described to early explorers and naturalists by Inuit hunters about polar bears using tools, 2) more recent documentation in the literature from Inuit hunters and scientists, and 3) recent observations of a polar bear in a zoo spontaneously using tools to access a novel food source. These observations and previously published experiments on brown bears (Ursus arctos) confirm that, in captivity, polar and brown bears are both capable of conceptualizing the use of a tool to obtain a food source that would otherwise not be accessible. Based on the information from all our sources, this may occasionally also have been the case in the wild. We suggest that possible tool use by polar bears in the wild is infrequent and mainly limited to hunting walruses because of their large size, difficulty to kill, and their possession of potentially lethal weapons for both their own defense and the direct attack of a predator.

Reconciling behavioral, bioenergetic, and oceanographic views of bowhead whale predation on overwintering copepods at an Arctic hotspot (Disko Bay, Greenland)

Banas, N.S., E.F. Møller, K.L. Laidre, M. Simon, I.H. Ellingsen, and T.G. Nielsen, "Reconciling behavioral, bioenergetic, and oceanographic views of bowhead whale predation on overwintering copepods at an Arctic hotspot (Disko Bay, Greenland)," Front. Mar. Sci., 8, doi:10.3389/fmars.2021.614582, 2021.

More Info

26 May 2021

Bowhead whales (Balaena mysticetus) visit Disko Bay, West Greenland in winter and early spring to feed on Calanus spp., at a time of year when the copepods are still mostly in diapause and concentrated in near-bottom patches. Combining past observations of copepod abundance and distribution with detailed observations of bowhead whale foraging behaviour from telemetry suggests that if the whales target the highest-density patches, they likely consume 26–75% of the Calanus standing stock annually. A parallel bioenergetic calculation further suggests that the whales' patch selection must be close to optimally efficient at finding hotspots of high density copepods near the sea floor in order for foraging in Disko Bay to be a net energetic gain. Annual Calanus consumption by bowhead whales is similar to median estimates of consumption by each of three zooplankton taxa (jellies, chaetognaths, and predatory copepods), and much greater than the median estimate of consumption by fish larvae, as derived from seasonal abundance and specific ingestion rates from the literature. The copepods' self-concentration during diapause, far from providing a refuge from predation, is the behaviour that makes this strong trophic link possible. Because the grazing impact of the whales comes 6–10 months later than the annual peak in primary production, and because Disko Bay sits at the end of rapid advective pathways (here delineated by a simple numerical particle-tracking experiment), it is likely that these Calanus populations act in part as a long-distance energetic bridge between the whales and primary production hundreds or thousands of km away.

More Publications

In The News

Arctic's 'last ice area' may be less resistant to global warming

The New York Times, Henry Fountain

The region, which could provide a last refuge for polar bears and other Arctic wildlife that depends on ice, is not as stable as previously thought, according to a new study.

1 Jul 2021

Arctic's 'last ice area' shows earlier-than-expected melt

Associated Press, Seth Borenstein

Part of the Arctic is nicknamed the 'Last Ice Area,' because floating sea ice there is usually so thick that it’s likely to withstand global warming for decades. So, scientists were shocked last summer when there was suddenly enough open water for a ship to pass through.

1 Jul 2021

Climate change: 'Last refuge' for polar bears is vulnerable to warming

BBC News, Matt McGrath

The region, dubbed the 'last ice area' had been expected to stay frozen far longer than other parts of the Arctic. But new analysis says that this area suffered record melting last summer. The researchers say that high winds allied to a changing climate were behind the unexpected decline.

1 Jul 2021

More News Items

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center