Janet T. Clarke

Janet T. Clarke
University of Washington Seattle | UW · Joint Institute for the Study of the Atmosphere and Ocean

About

45
Publications
11,957
Reads
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996
Citations
Additional affiliations
October 2013 - present
Leidos, Inc.
Position
  • Senior Scientist
February 1993 - June 1999
San Diego State University
Position
  • Lecturer
February 1988 - September 2013
SAIC
Position
  • Research Scientist

Publications

Publications (45)
Article
Full-text available
Place-based approaches to marine conservation identify areas that are crucial to the success of populations, species, communities, or ecosystems, and that may be candidates for special management actions. In the United States, the National Oceanic and Atmospheric Administration defined Biologically Important Areas (BIAs) for cetaceans (whales, dolp...
Article
Full-text available
We delineated and scored Biologically Important Areas (BIAs) in the Arctic region. The Arctic region extends from the Bering Strait to the Chukchi Sea, Beaufort Sea, Amundsen Gulf, and Viscount Melville Sound. This NOAA-led effort uses structured elicitation principles to build upon the first version of NOAA BIAs (BIA I) for cetaceans. In addition...
Article
Full-text available
We delineated and scored Biologically Important Areas (BIAs) for cetaceans in the Aleutian Islands and Bering Sea region. BIAs represent areas and times in which cetaceans are known to concentrate for activities related to reproduction, feeding, and migration, and also the known ranges of small and resident populations. This effort, the second led...
Article
Full-text available
Examining Eastern North Pacific gray whale (Eschrichtius robustus) carcasses and tracking mortality and morbidity are essential for assessing the health of this stock. In the eastern Chukchi Sea, the expansive coastline relative to few coastal communities makes monitoring for and physical examination of gray whale carcasses difficult. The Aerial Su...
Article
Full-text available
Successful reproduction is essential to a species existence. Here we summarize Bering-Chukchi-Beaufort (BCB) bowhead whale (Balaena mysticetus) calf distribution, ratio of calf to adult sightings, and encounter rate from data collected during line-transect aerial surveys conducted from July to October 2012-2019 in the western Beaufort Sea (140°W-15...
Article
Full-text available
Aerial line transect surveys were conducted during 19 July – 20 August in each of the years 2012 – 17, with onshore – offshore transects covering a study area of approximately 110 000 km2, from 140˚ W to 157˚ W longitude and from shore to 72˚ N latitude. These data were used to estimate abundance of the eastern Chukchi Sea (ECS) stock of beluga wha...
Article
Full-text available
Imagery and sighting data on bowhead whale (Balaena mysticetus) carcasses documented from 2009 to 2018 during aerial surveys in the eastern Chukchi and western Beaufort seas have provided evidence for killer whale (Orcinus orca) predation on bowhead whales of the Bering–Chukchi–Beaufort Seas stock. The Aerial Surveys of Arctic Marine Mammals (ASAMM...
Article
We analyzed data from line-transect aerial surveys for marine mammals conducted in the western Beaufort Sea (shore to 72˚ N, 140˚–157˚ W) from July to October of 2009–16 to investigate the distribution, behaviors, sighting rates, and habitat use preferences of bowhead and beluga whales. The habitat use data allowed for direct comparison with data c...
Article
Full-text available
Manned aerial surveys have been used successfully for decades to collect data to infer cetacean distribution, density (number of whales/km2), and abundance. Unmanned aircraft systems (UAS) have potential to augment or replace some manned aerial surveys for cetaceans. We conducted a three-way comparison among visual observations made by marine mamma...
Article
Full-text available
Cetacean occurrence in the Chukchi Sea is seasonal and primarily driven by annual sea ice retreat and prey occurrence in spring through fall. Humpback whales (Megaptera novaeangliae), fin whales (Balaenoptera physalus), and minke whales (Balaenoptera acutorostrata), although often found in polar waters elsewhere, are not common in the eastern Chukc...
Article
The range of the Bering-Chukchi-Beaufort (BCB) population of bowhead whales (Balaena mysticetus) extends across the seasonally ice-covered waters of the Pacific Arctic region. The majority of whales summer in the eastern Beaufort Sea and winter in the Bering Sea, migrating across the Chukchi Sea in fall and spring. As arctic sea-ice extent rapidly...
Article
Full-text available
The eastern Chukchi Sea (ECS) stock of beluga whales is one of three stocks in western Alaska that are co-managed by the National Marine Fisheries Service and the Alaska Beluga Whale Committee. Abundance of this stock was estimated as 3710 in 1991 from incomplete data. Analysis of data from satellite-linked time-depth recorders (SDRs) attached to b...
Technical Report
Full-text available
At the 2016 IWC Scientific Committee meeting, it was agreed that an annual or biannual report on the Bering-Chukchi-Beaufort Seas (BCB) bowhead whale stock summarizing various health-related statistics would be helpful for management and tracking the status of the BCBS population. This report is the first of the series and summarizes basic informat...
Article
The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific wa...
Article
The seasonal and geographic patterns in the distribution, residency, and density of two populations (Chukchi and Beaufort) of beluga whales (Delphinapterus leucas) were examined using data from aerial surveys, passive acoustic recordings, and satellite telemetry to better understand this arctic species in the oceanographically complex and changing...
Article
The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging grounds of North Pacific gray whales (Eschrichtius robustus). Benthic amphipods are considered the primary prey of gray whales in these waters, although no comprehensive quantitative analysis has been performed to support this assumption. Gray whale re...
Article
Full-text available
We analyzed data from line-transect aerial surveys for marine mammals conducted in the eastern Chukchi Sea (67˚–72˚ N, 157˚–169˚ W) in July to October of 2009–15 to investigate bowhead and gray whale distributions, behaviors, sighting rates, and habitat selection preferences, the last of which allowed direct comparison with results from data collec...
Article
Aerial surveys for bowhead whales have been conducted with a relatively consistent methodology over the Alaskan Beaufort Sea since 1989. Sightings of bowhead whales in the central Alaskan Beaufort Sea in September 1997 and September 2014 were unusual in that hundreds of whales were observed within a few kilometers of local barrier islands. We compa...
Article
The northern Bering and Chukchi seas are areas in the Pacific Arctic characterized by high northward advection of Pacific Ocean water, with seasonal variability in sea ice cover, water mass characteristics, and benthic processes. In this review, we evaluate the biological and environmental factors that support communities of benthic prey on the con...
Article
Full-text available
We integrated existing published and unpublished information to delineate Biologically Important Areas (BIAs) for bowhead, fin, gray, North Pacific right, and humpback whales and belugas in U.S. waters of the Aleutian Islands and Bering Sea. Supporting evidence for these BIAs came from aerial-, land-, and vessel-based surveys; satellite-tagging dat...
Article
Full-text available
In this assessment, we combined published and unpublished information to identify 16 Biologically Important Areas (BIAs) for bowhead whales, gray whales, and belugas in the U.S. Arctic. BIAs for bowhead whales and belugas were based on high-density areas used recurrently for reproduction, feeding, and migration, documented by visual surveys (aerial...
Article
In summer 2009 and 2010, as part of Chukchi Sea Offshore Monitoring in Drilling Area – Chemical and Benthos (COMIDA CAB) program, we performed a quantitative assessment of the biomass, abundance, and community structure of benthic infaunal populations of the Northeastern Chukchi Sea. This analysis documented a benthic species inventory of 361 taxa...
Article
Full-text available
The Western Arctic bowhead whale (Balaena mysticetus) is highly adapted to sea ice and annually migrates through the Bering, Chukchi, and Beaufort seas. While the overall distribution and seasonal movements of bowhead whales are mostly understood, information about their distribution in the Alaskan Beaufort Sea in early to mid-summer has not been w...
Article
Full-text available
The southern Chukchi Sea is one of the most productive areas in the world ocean. Over the past decade, there have been dramatic changes in this region in sea ice cover and in Bering Strait inflow, and it is now in the path of transpolar shipping and destinational ship traffic, including vessels supporting Arctic offshore oil and gas development and...
Data
Full-text available
The Western Arctic bowhead whale (Balaena mysticetus) is highly adapted to sea ice and annually migrates through the Bering, Chukchi, and Beaufort seas. While the overall distribution and seasonal movements of bowhead whales are mostly understood, information about their distribution in the Alaskan Beaufort Sea in early to mid-summer has not been w...
Article
Full-text available
Oceanographic features and physical processes in the ocean can create regions where prey, and therefore predators, may accumulate. Beluga whales Delphinapterus leucas are the most numerous cetacean in the Arctic. In the Alaskan Beaufort Sea, they prefer continental slope habitat in summer and autumn, presumably because such areas provide enhanced f...
Article
Satellite images, along with oceanographic, meteorological, and whale aerial survey data, are used to illustrate aspects of ocean circulation associated with a bowhead whale feeding ‘hotspot’ near Barrow, Alaska. In response to weak winds, a strong front forms near the shelf-break along the southern edge of Barrow Canyon when the Alaska Coastal Cur...
Article
Full-text available
A total of 821 gray whales were seen during aerial surveys in the northeastern Chukchi Sea from July through October 1982–1987. Gray whale distribution extended from south of Point Hope to northeast of Point Barrow, Alaska, between 0.5 and 166 km offshore. Monthly abundance estimates (number of whales/survey hour) were highest in July (6.81) and lo...
Article
Full-text available
A shock trial of a US Navy Destroyer, the USS Winston S. Churchill, was conducted offshore of northern Florida in May and June 2001. The shock trial consisted of three underwater detonation tests, spaced approximately one week apart. Environmental mitigation to minimise the impact of the shock trial on marine mammals and sea turtles was based on a...
Article
Full-text available
Gray whale (Eschrichtius robustus) reactions to offshore human activities have been relatively well studied compared to those of other mysticetes. Studies of short-term behavioural responses to underwater noise associated with aircraft, ships and seismic explorations indicate a 0.5 probability that whales will respond to continuous broadband noise...
Article
Full-text available
A total of 176 sightings of 488 gray whales ( Eschrichtius robustus) were made during 85.6 hours of aerial surveys in the southern Chukchi Sea and northern Bering Sea, east of the International Date Line, from August to early November 1980-1989. Surveys were flown infrequently and effort varied considerably between years and geographic areas. Gray...
Article
This technical report summarizes marine mammal occurrence data for five separate regions along coastal U.S. where military overflights occur. The five regions are the Northeast Pacific, Southeast Pacific, Gulf of Mexico, Southwest Atlantic, and Northwest Atlantic. The data include marine mammal species summary tables that provide the species common...
Article
Bowhead whales pass near or through offshore oil and gas lease areas in the northeastern Chukchi Sea during their westward migration each autumn. Results of aerial surveys conducted from mid-September through October 1982–1990 indicate that whale distribution overlapped lease area boundaries north and east of Point Barrow, Alaska. Bowhead relative...
Article
Full-text available
Migration route (mean depth at random sightings) was significantly different among years. Cumulative daily random sighting rate peaks in the northeastern Chukchi Sea were up to six times greater than those in the Alaskan Beaufort Sea. The proportion of cumulative random sightings in water ≥37m deep was significantly greater than the amount of surve...
Article
Spring Delphinapterus leucas distribution extended from waters north of St Lawrence Island, along nearshore leads between Point Hope and Point Barrow in the Chukchi Sea, to offshore leads east of Point Barrow along 71°30′N latitude in the Beaufort Sea. Annual spring abundance indices ranged from 24.83 whales/100km survey effort in 1980, to 4.22 wha...
Article
A bstract Although the distribution and relative abundance of bowhead whales varied annually within the fall whaling area near Barrow, Alaska, the distance of whales from shore was not significantly different among years 1982‐1989 (ANOVA, F = 0.5, P > 0.5). The minimum detectable distance for the ANOVA was 12 km (α= 0.05, β= 0.1). Annual median dis...
Article
Full-text available
Broad estimates of bowhead whale numbers in Beaufort Sea outer continental shelf (OCS) waters were calculated based on raw counts of whales seen during aerial surveys conducted in late summer 1982-84, corrected by factors accounting for surface area not sampled, surfaced whales missed by observers, and whales too deep to be seen. Annual estimates r...
Article
Full-text available
Aerial surveys of bowhead whales and, secondarily, other marine mammals were made from 1 Sep - 23 Oct 1987 in the western Beaufort and northeastern Chukchi Seas. A shore-based acoustic monitoring station was maintained at Barrow, Alaska from 9 Sept 21 Oct 1987 to record the calls of migrating bowhead whales as they passed into the northeastern Chuk...
Article
Seismic survey activities in the western Beaufort Sea, involving ships and sound production, were monitored in autumn 1982 for their possible effects on migrating Bowhead whales Balaena mysticetus. The study, begun in 1981 by die Minerals Management Service of the US Department of the Interior, covered offshore waters between the Alaskan coast and...
Article
Full-text available
Broad-scale aerial surveys of the Alaskan Beaufort Sea (140°-157°W) in autumn commenced in 1979, and have continued uninterrupted to the present. These surveys are now known as the Bowhead Whale Aerial Survey Project (BWASP). BWASP represents a multi-decadal time-series of data on distribution, abundance, and habitat preferences of Arctic marine ma...
Article
Full-text available
Broad-scale aerial surveys of the northeastern Chukchi Sea off Alaska were conducted from June-October 2008-2009, after a hiatus since 1991. These surveys are now known as the Chukchi Offshore Monitoring In Drilling Area (COMIDA) project. Climatic changes in the Arctic between the early 1990s and the present have been well-documented, including (bu...
Article
The report summarizes the 1991 investigations of the distribution, abundance, migration timing and route, behavior, and habitat relationships of endangered whales in the Alaskan Chukchi and western Beaufort seas (hereafter, study area); 1991 was the third year of a three year (1989-91) study. Data were collected during transect and search surveys f...
Article
In keeping with the National Environmental Policy Act (1969), the Marine Mammal Protection Act (1972) and the Endangered Species Act (1973), the OCS Lands Act Amendments (1978) established a management policy that included studies in OCS lease sale areas to ascertain potential environmental impacts of oil and gas development on OCS marine coastal e...
Article
Full-text available
We introduce a probability model for data arising from aerial line transect surveys, with the goal of estimating relative animal density. This model includes considera-tion of animal clustering and censored observations due to effort truncation and flights with zero animal sightings. It also includes terms for spatio-temporal covariates that affect...

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