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Kristin Laidre

Principal Oceanographer

Assistant Professor, Fisheries

Email

klaidre@apl.washington.edu

Phone

206-616-9030

Department Affiliation

Polar Science Center

Kristin Laidre's Website

http://staff.washington.edu/klaidre

Publications

2000-present and while at APL-UW

The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994

Trukhanova, I.S., A.I. Grachev, A.G. Somov, V.N. Burkanod, K.L. Laidre, and P.L. Boveng, "The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994," Plos One, 12, doi:10.1371/journal.pone.0182725, 2017.

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10 Aug 2017

Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (Pusa hispida), ribbon (Histriophoca fasciata), bearded (Erignathus barbatus) and spotted (Phoca largha) seal. Variations in catch per unit effort were explored in relation to year, sea ice conditions, day of the year, and geographic location. In most years, the harvest was predominantly represented by ringed seals (mean = 0.43, range 0.25–0.67), followed by ribbon (mean = 0.31, range 0.15–0.43), spotted (mean = 0.19, range 0.11–0.35) and bearded seals (mean = 0.07, range 0.03–0.14). The struck-and-lost percentages were as high as 30–35% for ringed, bearded and spotted seals and 15–20% for ribbon seals. Catch per unit effort (number of seals/skiff*day) for ringed, ribbon, and spotted seals had a similar seasonal pattern with a distinct spike in catches for spotted seals in the first week of May, for ribbon seals in the last week of May, and for ringed seals in the second week of June. Catches of bearded seals showed a less pronounced temporal structure with a gradual increase toward the end of the harvest season in the majority of years. Spatial distribution of harvest effort followed closely with seal distribution obtained from aerial surveys. These data could be used as a source of information on seal herd location throughout the breeding and molting seasons and for more complex demographic or life-table models. We did not find any evidence of the decline of catch per unit effort over the study period. Timely introduction of state regulations and efficient harvest management apparently prevented severe depletion of ice-associated seal populations in the Sea of Okhotsk during the periods of their intense exploitation.

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., EOR, doi:10.1007/s00300-017-2172-6, 2017.

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10 Jul 2017

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.

Decadal shifts in autumn migration timing by Pacific Arctic beluga whales are related to delayed annual sea ice formation

Hauser, D.D.W., K.L. Laidre, K.M. Stafford, H.L. Stern, R.S. Suydam, and P.R. Richard, "Decadal shifts in autumn migration timing by Pacific Arctic beluga whales are related to delayed annual sea ice formation," Global Clim. Change, 23, 2206-2217, doi:10.111/gcb.13564, 2017.

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1 Jun 2017

Migrations are often influenced by seasonal environmental gradients that are increasingly being altered by climate change. The consequences of rapid changes in Arctic sea ice have the potential to affect migrations of a number of marine species whose timing is temporally matched to seasonal sea ice cover. This topic has not been investigated for Pacific Arctic beluga whales (Delphinapterus leucas) that follow matrilineally maintained autumn migrations in the waters around Alaska and Russia. For the sympatric Eastern Chukchi Sea ('Chukchi') and Eastern Beaufort Sea ('Beaufort') beluga populations, we examined changes in autumn migration timing as related to delayed regional sea ice freeze-up since the 1990s, using two independent data sources (satellite telemetry data and passive acoustics) for both populations. We compared dates of migration between 'early' (1993–2002) and 'late' (2004–2012) tagging periods. During the late tagging period, Chukchi belugas had significantly delayed migrations (by 2 to >4 weeks, depending on location) from the Beaufort and Chukchi seas. Spatial analyses also revealed that departure from Beaufort Sea foraging regions by Chukchi whales was postponed in the late period. Chukchi beluga autumn migration timing occurred significantly later as regional sea ice freeze-up timing became later in the Beaufort, Chukchi, and Bering seas. In contrast, Beaufort belugas did not shift migration timing between periods, nor was migration timing related to freeze-up timing, other than for southward migration at the Bering Strait. Passive acoustic data from 2008 to 2014 provided independent and supplementary support for delayed migration from the Beaufort Sea (4 day yr) by Chukchi belugas. Here, we report the first phenological study examining beluga whale migrations within the context of their rapidly transforming Pacific Arctic ecosystem, suggesting flexible responses that may enable their persistence yet also complicate predictions of how belugas may fare in the future.

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In The News

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

Stressed-out narwhals don't know whether to freeze or flee, scientists find

National Public Radio, Nell Greenfieldboyce

Kristin Laidre notes that this new scientific study provides a new physiological angle on the vulnerability of narwhals to anthropogenic disturbance in the Arctic.

7 Dec 2017

Narwhals are helping NASA understand melting ice and rising seas

Bloomberg, Adam Popescu

Greenland's ice cap holds beneath it 10 percent of the earth's freshwater, enough to raise global sea levels by 20 feet. While there's no doubt it is melting, scientists have little certainty about exactly what's happening inside this 10,000-year-old ice roughly three time size of Texas.

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24 Aug 2017

Greenland's ice cap holds beneath it 10 percent of the earth's freshwater, enough to raise global sea levels by 20 feet. While there's no doubt it is melting, scientists have little certainty about exactly what's happening inside this 10,000-year-old ice roughly three time size of Texas.

Last winter was the warmest on record in the Arctic, and as Greenland heats up, understanding this glaciate has become essential to navigating our future.

That's why scientists need narwhals, whales with 9 foot long unicorn-like tusks, which are some of the only mammals benefiting from all that melting ice.

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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
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