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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

Transient benefits of climate change for a high-Arctic polar bear (Ursus maritimus) subpopulation

Laidre, K.L., S.N. Atkinson, E.V. Regehr, H.L. Stern, E.W. Born, Ø. Wiig, N.J. Lunn, M Dyck, P. Heagerty, B.R. Cohen, "Transient benefits of climate change for a high-Arctic polar bear (Ursus maritimus) subpopulation," Global Change Biol., EOR, doi:10.1111/gcb.15286, 2020.

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23 Sep 2020

Kane Basin (KB) is one of the world's most northerly polar bear (Ursus maritimus) subpopulations, where bears have historically inhabited a mix of thick multiyear and annual sea ice year‐round. Currently, KB is transitioning to a seasonally ice‐free region because of climate change. This ecological shift has been hypothesized to benefit polar bears in the near‐term due to thinner ice with increased biological production, although this has not been demonstrated empirically. We assess sea‐ice changes in KB together with changes in polar bear movements, seasonal ranges, body condition, and reproductive metrics obtained from capture–recapture (physical and genetic) and satellite telemetry studies during two study periods (1993–1997 and 2012–2016). The annual cycle of sea‐ice habitat in KB shifted from a year‐round ice platform (~50% coverage in summer) in the 1990s to nearly complete melt‐out in summer (<5% coverage) in the 2010s. The mean duration between sea‐ice retreat and advance increased from 109 to 160 days (p = .004). Between the 1990s and 2010s, adult female (AF) seasonal ranges more than doubled in spring and summer and were significantly larger in all months. Body condition scores improved for all ages and both sexes. Mean litter sizes of cubs‐of‐the‐year (C0s) and yearlings (C1s), and the number of C1s per AF, did not change between decades. The date of spring sea‐ice retreat in the previous year was positively correlated with C1 litter size, suggesting smaller litters following years with earlier sea‐ice breakup. Our study provides evidence for range expansion, improved body condition, and stable reproductive performance in the KB polar bear subpopulation. These changes, together with a likely increasing subpopulation abundance, may reflect the shift from thick, multiyear ice to thinner, seasonal ice with higher biological productivity. The duration of these benefits is unknown because, under unmitigated climate change, continued sea‐ice loss is expected to eventually have negative demographic and ecological effects on all polar bears.

Seasonal detections of bearded seal (Erignathus barbatus) vocalizations in Baffin Bay and Davis Strait in relation to sea ice concentration

Boye, T.K., M.J. Simon, K.L. Laidre, F. Rignét, and K.M. Stafford, "Seasonal detections of bearded seal (Erignathus barbatus) vocalizations in Baffin Bay and Davis Strait in relation to sea ice concentration," Polar Biol., EOR, doi:10.1007/s00300-020-02723-1, 2020.

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8 Aug 2020

There is limited information about the biology and seasonal distribution of bearded seals (Erignathus barbatus) in Greenland. The species is highly ice-associated and depends on sea ice for hauling out and giving birth, making it vulnerable to climate change. We investigated the seasonality and distribution of bearded seal vocalizations at seven different locations across southern Baffin Bay and Davis Strait, West Greenland. Aural M2 and HARUphone recorders were deployed on the sea bottom during 2006–2007 and 2011–2013. Recordings were analyzed for presence/absence of bearded seal calls relative to location (including distance to shore and depth), mean sea ice concentration and diel patterns. Calling occurred between November and late June with most intense calling during the mating season at all sites. There was a clear effect of depth and distance to shore on the number of detections, and the Greenland shelf (< 300 m) appeared to be the preferred habitat for bearded seals during the mating season. These results suggest that bearded seals may retreat with the receding sea ice to Canada during summer or possibly spend the summer along the West Greenland coast. It is also possible that, due to seasonal changes in bearded seal vocal behavior, animals may have been present in our study area in summer, but silent. The number of detections was affected by the timing of sea ice formation but not sea ice concentration. Diel patterns were consistent with patterns found in other parts of the Arctic, with a peak during early morning (0400 local) and a minimum during late afternoon (1600 local). While vocalization studies have been conducted on bearded seals in Norwegian, Canadian, northwest Greenland, and Alaskan territories, this study fills the gap between these areas.

Grounded icebergs as maternity denning habitat for polar bears (Ursus maritimus) in North and Northeast Greenland

Laidre, K.L., and I. Stirling, "Grounded icebergs as maternity denning habitat for polar bears (Ursus maritimus) in North and Northeast Greenland," Polar Biol., 43, 937-943, doi:10.1007/s00300-020-02695-2, 2020.

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1 Jul 2020

This study provides the first documentation of polar bear (Ursus maritimus) maternity denning in snowdrifts around icebergs frozen into the fast ice or grounded on the seafloor. Based on six den observations in north and northeast Greenland during spring surveys in 2018 and 2019 (109 flight hours), together with observations of 20 adult females with 35 cubs of the year (COYs) in adjacent sea ice, we hypothesize that the use of snowdrifts around icebergs for maternity denning is an established behavior in the region and not a random event. Factors influencing maternity denning in snowdrifts around icebergs may include limited suitable drifts on the nearby terrestrial polar desert due to low precipitation, the presence of suitable wind-blown snow banks regardless of the direction of autumn storm winds, cold and stable habitat throughout the winter denning period, and access to ringed seal (Pusa hispida) pupping habitat in the nearby Northeast Water polynya. This type of maternity denning habitat is only available in glaciated regions of the Arctic where marine-terminating glaciers deposit mélange large enough to become grounded offshore and remain in place for months or years. This habitat may become less stable or disappear with long-term climate warming.

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In The News

Beluga whale spotted off San Diego washes up dead on Baja beach, thousands of miles from home

Newsweek, Hannah Osborne

The beluga spotted in July, 2500 miles from the nearest known beluga population, has been found dead. Kristin Laidre speculates where the whale may have come from and why it had ranged so far from home.

7 Oct 2020

Some polar bears in far north are getting short-term benefit from thinning ice

UW News, Hannah Hickey

A small subpopulation of polar bears lives on what used to be thick, multiyear sea ice far above the Arctic Circle. They are healthier as conditions are warming because thinning and shrinking multiyear sea ice is allowing more sunlight to reach the ocean surface, which makes the ecosystem more productive. photo: Carsten Egevang

23 Sep 2020

Beluga whale sighted off San Diego coast mystifies scientists

National Geographic, Jason G. Goldman

A beluga whale has been sighted off the coast of southern California. Kristin Laidre is asked to speculate how and why it was found thousands of miles from its native range.

10 Jul 2020

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