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Kate Stafford

Affiliate

Email

stafford@apl.washington.edu

Department Affiliation

Acoustics

Education

B.A. French Literature, Minor: Biology, University of California - Santa Cruz, 1989

M.S. Wildlife Biology, Oregon State University, 1995

Ph.D. Interdisciplinary Oceanography, Oregon State University, 2001

Publications

2000-present and while at APL-UW

Marine mammal detections on the Chukchi Plateau 2009–2020

Stafford, K.M. H. Melling, S.E. Moore, C.L. Berchok, E.K. Braen, A.M. Brewer, and B.M. Kimber, "Marine mammal detections on the Chukchi Plateau 2009–2020," J. Acoust. Soc. Am., 151, 2521-2529, doi:10.1121/10.0010208, 2022.

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12 Apr 2022

The Arctic Ice Monitoring (AIM) observatory has been maintained on the Chukchi Plateau at 75.1° N 168.0° W nearly continuously since 2003. The AIM site consists of a submerged mooring that, since October 2008, has been instrumented with a passive acoustic recorder to sample ambient sound, with a focus on marine mammal detections in the High Arctic. Year-long data sets for 2009, 2012, and 2014–2020 were analyzed for the presence of signals from Arctic species including bowhead and beluga whales, bearded seals, and walrus. Calls from subarctic ribbon seals were commonly detected in autumn months, suggesting they have expanded their distribution much further northward. Killer whale calls were detected in recent years providing evidence that they have moved further north into the Pacific Arctic. No other subarctic cetaceans were heard. Year-round passive acoustic sampling of sounds produced by marine mammals over a decadal timescale has enhanced our understanding of how climate-driven changes in biodiversity are affecting even the very High Arctic.

Changes in gray whale phenology and distribution related to prey variability and ocean biophysics in the northern Bering and eastern Chukchi seas

Moore, S.E., J.T. Clarke, S.R. Okkonen, J.M. Grebmeier, C.L. Berchok, and K.M. Stafford, "Changes in gray whale phenology and distribution related to prey variability and ocean biophysics in the northern Bering and eastern Chukchi seas," Plos One, 17, doi:10.1371/journal.pone.0265934, 2022.

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7 Apr 2022

Changes in gray whale (Eschrichtius robustus) phenology and distribution are related to observed and hypothesized prey availability, bottom water temperature, salinity, sea ice persistence, integrated water column and sediment chlorophyll a, and patterns of wind-driven biophysical forcing in the northern Bering and eastern Chukchi seas. This portion of the Pacific Arctic includes four Distributed Biological Observatory (DBO) sampling regions. In the Bering Strait area, passive acoustic data showed marked declines in gray whale calling activity coincident with unprecedented wintertime sea ice loss there in 2017–2019, although some whales were seen there during DBO cruises in those years. In the northern Bering Sea, sightings during DBO cruises show changes in gray whale distribution coincident with a shrinking field of infaunal amphipods, with a significant decrease in prey abundance (r = –0.314, p<0.05) observed in the DBO 2 region over the 2010–2019 period. In the eastern Chukchi Sea, sightings during broad scale aerial surveys show that gray whale distribution is associated with localized areas of high infaunal crustacean abundance. Although infaunal crustacean prey abundance was unchanged in DBO regions 3, 4 and 5, a mid-decade shift in gray whale distribution corresponded to both: (i) a localized increase in infaunal prey abundance in DBO regions 4 and 5, and (ii) a correlation of whale relative abundance with wind patterns that can influence epi-benthic and pelagic prey availability. Specifically, in the northeastern Chukchi Sea, increased sighting rates (whales/km) associated with an ~110 km (60 nm) offshore shift in distribution was positively correlated with large scale and local wind patterns conducive to increased availability of krill. In the southern Chukchi Sea, gray whale distribution clustered in all years near an amphipod-krill 'hotspot' associated with a 50–60-m deep trough. We discuss potential impacts of observed and inferred prey shifts on gray whale nutrition in the context of an ongoing unusual gray whale mortality event. To conclude, we use the conceptual Arctic Marine Pulses (AMP) model to frame hypotheses that may guide future research on whales in the Pacific Arctic marine ecosystem.

Fine-scale spatial and temporal acoustic occurrence of island-associated odontocetes near a mid-ocean atoll in the northern Indian Ocean

Panicker, D., M.F. Baumgartner, and K.M. Stafford, "Fine-scale spatial and temporal acoustic occurrence of island-associated odontocetes near a mid-ocean atoll in the northern Indian Ocean," Mar. Ecol. Prog. Seri., EOR, doi:10.3354/meps13947, 2022.

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3 Feb 2022

Temporal patterns of oceanic predators can provide valuable information on both lunar and diel influences on not just these predator distributions, but also on their prey patches that are often difficult to study. Mid-oceanic island chains in the northern Indian Ocean have high odontocete occurrence, however, the ecology of these animals is not well characterized. Our study aims to understand fine-scale spatial and temporal patterns of island-associated odontocetes using passive acoustic monitoring from January 2019 to January 2020 around Kavaratti Island, Lakshadweep, India. Based on opportunistic recordings in the presence of odontocetes, the majority of the detected whistles were likely made by spinner dolphins (Stenella longirostris). We identified a resident population whose whistle occurrence was significantly influenced by month, site, diel and lunar cycles. Higher acoustic detections were observed in the northeast monsoon month of November and lower detections observed during pre-monsoon and southwest monsoon periods. Distinct day-night differences along with fine-scale temporal variability were also observed suggesting delphinids use nearshore waters as a daytime resting habitat. Odontocete detections were highest during the new moon period and lowest during the first quarter phase. Detection rates were higher on the south side of the island. Our study shows that solar and lunar cycles modulate odontocete vocal occurrence, presumably through influences on their prey. Similarities of odontocete occurrence around Lakshadweep to other mid-oceanic island chains suggests that an island-associated micronekton community may exist around Lakshadweep that may also be important to other pelagic species targeted by local fisheries.

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In The News

This year's Arctic Report Card is filled with predictable trends and new obstacles

Anchorage Daily News, Ned Rozell

One hundred eleven experts on the land, ocean, and ice north of the Arctic Circle pitched in to write the 2021 Arctic Report Card. The trends scientists spoke of in 2006 – the first report card – have become more extreme since then. Kate Stafford reports increasing man-made noises in the Bering Strait, a place rich with marine mammal songs.

18 Dec 2021

Ocean Jazz

The Loh Down on Science (Podcast), Ted Yoo

This one-minute broadcast, packed with humor and insight, is informed by Kate Stafford's recently published findings on the diversity of songs vocalized by Spitsbergen’s bowhead whales.

2 Jul 2021

Endangered blue whales recorded off southwest coast of India

UW News, Hannah Hickey

"The presence of blue whales in Indian waters is well known from several strandings and some live sightings of blue whales," said lead author Divya Panicker. "But basic questions such as where blue whales are found, what songs do they sing, what do they eat, how long do they spend in Indian waters and in what seasons are still largely a mystery."

9 Jun 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
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