APL-UW Home

Jobs
About
Campus Map
Contact
Privacy
Intranet

Kate Stafford

Senior Principal Oceanographer

Affiliate Associate Professor, Oceanography

Email

stafford@apl.washington.edu

Phone

206-685-8617

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

Interannual variability in acoustic detection of blue and fin whale calls in the Northeast Atlantic High Arctic between 2008 and 2018

Ahonen, H., K.M. Stafford, C. Lydersen, C.L. Berchok, S.E. Moore, and K.M. Kovacs, "Interannual variability in acoustic detection of blue and fin whale calls in the Northeast Atlantic High Arctic between 2008 and 2018," Endanger. Species Res., 45, 209-224, doi:10.3354/esr01132, 2021.

More Info

15 Jul 2021

Northern Hemisphere blue and fin whales are regular summer migrants to Arctic waters. Given the profound changes the Arctic is currently undergoing due to global warming, changes in habitat use and distribution of these migratory species are predicted. In this study, 3 passive acoustic recorders, 2 in Fram Strait about 95 km apart and 1 north of the Svalbard Archipelago (Atwain), were used to investigate the spatial and temporal vocal occurrence of these species in the Northeast Atlantic High Arctic. Acoustic data were available for 7 years for western Fram Strait (WFS), 2.5 years for central Fram Strait (CFS) and 3 years for Atwain. At both Fram Strait locations, most blue whale call detections occurred from August through October, though recently (2015–2018) in WFS a clear increase in blue whale call rates was detected in June/July, suggesting an expansion of the seasonal occurrence of blue whales. In WFS, fin whale calls were detected intermittently, at low levels, almost year-round. In CFS, fin whale calls were more frequent but occurred mainly from July through December. At Atwain, blue whale detections commenced in July, both species were recorded in September/October and fin whale calls extended into November. Results from this study provide novel long-term baseline information about the occurrence of blue and fin whales at extreme northerly locations, where traditional ship-based survey methods are seasonally limited. Continued sampling will support investigation of how environmental change influences cetacean distribution and habitat use.

Bowhead and beluga whale acoustic detections in the western Beaufort Sea 2008–2018

Stafford, K.M., J.J. Citta, S.R. Okkonen, and J. Zhang, "Bowhead and beluga whale acoustic detections in the western Beaufort Sea 2008–2018," Plos One, 16, doi:10.1371/journal.pone.0253929, 2021.

More Info

28 Jun 2021

The Distributed Biological Observatory (DBO) was established to detect environmental changes in the Pacific Arctic by regular monitoring of biophysical responses in each of 8 DBO regions. Here we examine the occurrence of bowhead and beluga whale vocalizations in the western Beaufort Sea acquired by acoustic instruments deployed from September 2008 – July 2014 and September 2016 – October 2018 to examine inter-annual variability of these Arctic endemic species in DBO Region 6. Acoustic data were collected on an oceanographic mooring deployed in the Beaufort shelfbreak jet at ~71.4°N, 152.0°W. Spectrograms of acoustic data files were visually examined for the presence or absence of known signals of bowhead and beluga whales. Weekly averages of whale occurrence were compared with outputs of zooplankton, temperature and sea ice from the BIOMAS model to determine if any of these variables influenced whale occurrence. In addition, the dates of acoustic whale passage in the spring and fall were compared to annual sea ice melt-out and freeze-up dates to examine changes in phenology. Neither bowhead nor beluga whale migration times changed significantly in spring, but bowhead whales migrated significantly later in fall from 2008–2018. There were no clear relationships between bowhead whales and the environmental variables, suggesting that the DBO 6 region is a migratory corridor, but not a feeding hotspot, for this species. Surprisingly, beluga whale acoustic presence was related to zooplankton biomass near the mooring, but this is unlikely to be a direct relationship: there are likely interactions of environmental drivers that result in higher occurrence of both modeled zooplankton and belugas in the DBO 6 region. The environmental triggers that drive the migratory phenology of the two Arctic endemic cetacean species likely extend from Bering Sea transport of heat, nutrients and plankton through the Chukchi and into the Beaufort Sea.

Estimating acoustic cue rates in bowhead whales, Balaena mysticetus, during their fall migration through the Alaskan Beaufort Sea

Blackwell, S.B., A.M. Thode, A.S. Conrad, M.C. Ferguson, C.L. Berchok, K.M. Stafford, T.A. Marques, and K.H. Kim, "Estimating acoustic cue rates in bowhead whales, Balaena mysticetus, during their fall migration through the Alaskan Beaufort Sea," J. Acoust. Soc. Am., 149, 3611-, doi:10.1121/10.0005043, 2021.

More Info

26 May 2021

Eight years of passive acoustic data (2007–2014) from the Beaufort Sea were used to estimate the mean cue rate (calling rate) of individual bowhead whales (Balaena mysticetus) during their fall migration along the North Slope of Alaska. Calls detected on directional acoustic recorders (DASARs) were triangulated to provide estimates of locations at times of call production, which were then translated into call densities (calls/h/km2). Various assumptions were used to convert call density into animal cue rates, including the time for whales to cross the arrays of acoustic recorders, the population size, the fraction of the migration corridor missed by the localizing array system, and the fraction of the seasonal migration missed because recorders were retrieved before the end of the migration. Taking these uncertainties into account in various combinations yielded up to 351 cue rate estimates, which summarize to a median of 1.3 calls/whale/h and an interquartile range of 0.5–5.4 calls/whale/h.

More Publications

In The News

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

Noise pollution is harming sea life, needs to be prioritized, scientists say

Reuters, Sharon Bernstein

Oceanographer Kate Stafford, commenting on a comprehensive review of over 500 research papers published in Science says, "The review makes it clear that, to actually reduce anthrophony (human noise) and aim for a well-managed future, ... we will need global cooperation among governments."

4 Feb 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
Close

 

Close