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Kristin Laidre

Principal Oceanographer

Assistant Professor, Fisheries





Department Affiliation

Polar Science Center

Kristin Laidre's Website



2000-present and while at APL-UW

Indirect effects of sea ice loss on summer–fall habitat and behaviour for sympatric populations of an Arctic marine predator

Hauser, D.D.W., K.L. Laidre, H.L. Stern, R.S. Suydam, and P.R. Richard, "Indirect effects of sea ice loss on summer–fall habitat and behaviour for sympatric populations of an Arctic marine predator," Divers. Distrib., EOR, doi:10.1111/ddi.12722, 2018.

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1 Feb 2018

Climate change is fundamentally altering habitats, with complex consequences for species across the globe. The Arctic has warmed 2–3 times faster than the global average, and unprecedented sea ice loss can have multiple outcomes for ice‐associated marine predators. Our goal was to assess impacts of sea ice loss on population‐specific habitat and behaviour of a migratory Arctic cetacean.

Using satellite telemetry data collected during summer–fall from sympatric beluga whale (Delphinapterus leucas) populations ("Chukchi" and "Beaufort" belugas), we applied generalized estimating equations to evaluate shifts in sea ice habitat associations and diving behaviour during two periods: 1993–2002 ("early") and 2004–2012 ("late"). We used resource selection functions to assess changes in sea ice selection as well as predict trends in habitat selection and "optimal" habitat, based on satellite‐derived sea ice data from 1990 to 2014.

Sea ice cover declined substantially between periods, and Chukchi belugas specifically used significantly lower sea ice concentrations during the late than early period. Use of bathymetric features did not change between periods for either population. Population‐specific sea ice selection, predicted habitat and the amount of optimal habitat also generally did not change during 1990–2014. Chukchi belugas tracked during 2007–2012 made significantly more long‐duration and deeper dives than those tracked during 1998–2002.

Taken together, our results suggest bathymetric parameters are consistent predictors of summer–fall beluga habitat rather than selection for specific sea ice conditions during recent sea ice loss. Beluga whales were able to mediate habitat change despite their sea ice associations. However, trends towards prolonged and deeper diving possibly indicate shifting foraging opportunities associated with ecological changes that occur in concert with sea ice loss. Our results highlight that responses by some Arctic marine wildlife can be indirect and variable among populations, which could be included in predictions for the future.

Range contraction and increasing isolation of a polar bear subpopulation in an era of sea‐ice loss

Laidre, K.L., E.W. Born, S.N. Atkinson, Ø. Wiig, L.W. Andersen, N.J. Lunn, M. Dyck, E.V. Regehr, R. McGovern, and P. Heagerty, "Range contraction and increasing isolation of a polar bear subpopulation in an era of sea‐ice loss," Ecol. Evol., 8, 2062-2075, doi:10.1002/ece3.3809, 2018.

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1 Feb 2018

Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear (Ursus maritimus) subpopulation over a 25‐year period of sea‐ice loss. Satellite telemetry collected from n = 43 (1991–1995) and 38 (2009–2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km2 (SE 58,000) to 211,000 km2 (SE 23,000) (p < .001). Between the 1990s and 2000s, there was a significant shift northward during the on‐ice seasons (2.6° shift in winter median latitude, 1.1° shift in spring median latitude) and a significant range contraction in the ice‐free summers. Bears in the 2000s were less likely to leave BB, with significant reductions in the numbers of bears moving into Davis Strait (DS) in winter and Lancaster Sound (LS) in summer. Harvest recoveries suggested both short and long‐term fidelity to BB remained high over both periods (83–99% of marked bears remained in BB). Genetic analyses using eight polymorphic microsatellites confirmed a previously documented differentiation between BB, DS, and LS; yet weakly differentiated BB from Kane Basin (KB) for the first time. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long‐term sea‐ice loss. This may be indicative of future patterns for other polar bear subpopulations under climate change.

Identifying shifts in maternity den phenology and habitat characteristics of polar bears (Ursus maritimus) in Baffin Bay and Kane Basin

Escajeda, E., K.L. Laidre, E.W. Born, Ø. Wiig, S. Atkinson, M. Dyck, S.H. Ferguson, and N.J. Lunn, "Identifying shifts in maternity den phenology and habitat characteristics of polar bears (Ursus maritimus) in Baffin Bay and Kane Basin," Polar Biol., 41, 87-100, doi:10.1007/s00300-017-2172-6, 2017.

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1 Jan 2018

The phenology and habitat selection of polar bear (Ursus maritimus) maternity dens may shift over time in response to changing environmental conditions. We compared maternity den phenology and habitat characteristics using satellite telemetry data from adult female polar bears from the Baffin Bay (BB) (n = 16 dens; 2009–2015) and Kane Basin (KB) subpopulations (n = 3 dens; 2012–2015) to previously published maternity den data from 1991 to 1997 (BB n = 8 dens; KB n = 3 dens). BB maternity denning duration decreased from a mean of 194.1 days (SD = 21.0 days, n = 8) in the 1990s, to a mean of 167.1 days (SD = 27.6 days, n = 16; p = 0.017) in the 2000s. Delayed den entry accounted for shorter denning durations (1990s entry date x = 7 September; 2000s entry date x = 5 October; p = 0.018). For dens habitat characteristics of which could be measured, BB maternity dens in the 2000s occurred at higher elevations (x = 707.0 m, SD = 284.9 m, n = 15; p = 0.003) and greater slopes (x = 23.1°, SD = 7.4°; p = 0.003) than the 1990s (elevation x ± SD = 351.3 ± 194.5 m, n = 8; slope x ± SD = 11.9 ± 6.4±). Aspect also significantly differed between the 1990s (x = 51.3±) and 2000s BB maternity dens (x = 199.7±; Watson’s U2p = 0.042). KB dens were not statistically compared due to low sample size (n = 3 dens in both periods). Shifts in sea ice phenology and snow availability may explain the observed changes.

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In The News

Beluga whales dive deeper, longer to find food in Arctic

UW News, Michelle Ma

Beluga whales that spend summers feeding in the Arctic are diving deeper and longer to find food than in earlier years, when sea ice covered more of the ocean for longer periods, according to a new analysis led by University of Washington researchers.

20 Feb 2018

Research uncovers the mysterious lives of narwhals

UW News

"Arctic marine mammals are really good indicators of climate change because they are very specialized," says Kristin Laidre. "They are finely attuned to specific environmental conditions, so they are good indicator species for how the physical changes many scientists are documenting in the Arctic can reverberate throughout the ecosystem."

9 Feb 2018

Human disturbance hits narwhals where it hurts — the heart

Washington Post, Ben Guarino

Kristen Laidre comments that the paper "provides a new angle on the vulnerability of narwhals to anthropogenic disturbance, which is linked to the sweeping environmental changes we are observing across the Arctic."

7 Dec 2017

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