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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., 26, 6251-6265, doi:10.1111/gcb.15286, 2020.

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1 Nov 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.

The impact of rising sea temperatures on an Arctic top predator, the narwhal

Chambault, P., and 13 others including K.L. Laidre, "The impact of rising sea temperatures on an Arctic top predator, the narwhal," Sci. Rep., 10, 18678, doi:10.1038/s41598-020-75658-6, 2020.

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29 Oct 2020

Arctic top predators are expected to be impacted by increasing temperatures associated with climate change, but the relationship between increasing sea temperatures and population dynamics of Arctic cetaceans remains largely unexplored. Narwhals (Monodon monoceros) are considered to be among the most sensitive of Arctic endemic marine mammals to climate change due to their limited prey selection, strict migratory patterns and high site fidelity. In the context of climate change, we assume that the population dynamics of narwhals are partly influenced by changes in environmental conditions, with warm areas of increasing sea temperatures having lower abundance of narwhals. Using a unique large dataset of 144 satellite tracked narwhals, sea surface temperature (SST) data spanning 25 years (1993–2018) and narwhal abundance estimates from 17 localities, we (1) assessed the thermal exposure of this species, (2) investigated the SST trends at the summer foraging grounds, and (3) assessed the relationship between SST and abundance of narwhals. We showed a sharp SST increase in Northwest, Mideast and Southeast Greenland, whereas no change could be detected in the Canadian Arctic Archipelago (CAA) and in the Greenland Sea. The rising sea temperatures were correlated with the smallest narwhal abundance observed in the Mideast and Southeast Greenland (< 2000 individuals), where the mean summer sea temperatures were the highest (6.3°C) compared to the cold waters of the CAA (0.7°C) that were associated with the largest narwhal populations (> 40,000 individuals). These results support the hypothesis that warming ocean waters will restrict the habitat range of the narwhal, further suggesting that narwhals from Mideast and Southeast Greenland may be under pressure to abandon their traditional habitats due to ocean warming, and consequently either migrate further North or locally go extinct.

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., 43, 1493-1502, 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.

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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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