Satellite-monitored movements of radio-tagged bowhead whales in the Beaufort and Chukchi seas during the late-summer feeding season and fall migration

From 30 August to 6 September 1992, we tagged 12 juvenile bowhead whales (Balaena mysticetus) with Argos satellite-monitored radio tags in the Canadian Beaufort Sea off the Mackenzie River Delta. Eight tags documented [Formula: see text]9820 km of movements between 392 locations during 111 whale-tracking days. The whales did not move in unison. Individual movements and average speeds (1.1-5.8 km/h) varied widely. One whale stayed in Mackenzie Bay for 23.5 d, while the rest stayed an average of only 2.4 d. The majority of locations for all whales were in shallow water: 65% at <50 m depth and 87% at <100 m depth. Seven whales went into water >100 m deep and four were in water >500 m deep. The whale with the longest record traveled [Formula: see text]3886 km to Siberia in 32.5 d, averaging 5.0 km/h. Its westerly route through the Beaufort and Chukchi seas was between 70° and 72°N and primarily in heavy ice ([Formula: see text]90% coverage), which was continuous west of 151°W. This whale's speed was faster, though not significantly, in heavy ice than in more open water. This is the first detailed documentation of the route and speed of a bowhead whale during its fall migration from Canadian to Russian waters.

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Observations of Beachcast Bowhead Whales (Balaena mysticetus) in the Southeastern Beaufort Sea and Amundsen Gulf, 1987–2016

The Canadian Field-Naturalist ◽

10.22621/cfn.v131i3.2028 ◽

2018 ◽

Vol 131 (3) ◽

pp. 270-279

Author(s):

Lois A. Harwood ◽

Ellen V. Lea ◽

Stephen A. Raverty ◽

Patricia A. Hall ◽

Erin Linn ◽

...

Keyword(s):

Beaufort Sea ◽

Bowhead Whale ◽

Grizzly Bears ◽

Balaena Mysticetus ◽

Adult Group ◽

Mature Adult ◽

Bowhead Whales ◽

Mature Adults ◽

Amundsen Gulf ◽

Summer Feeding

Each spring, most Bowhead Whales (Balaena mysticetus) of the Bering-Chukchi-Beaufort (BCB) population migrate to the Canadian Beaufort Sea and Amundsen Gulf for summer feeding. Occasionally, Inuvialuit hunters and others observe beachcast (stranded) or adrift Bowhead Whale carcasses. From 1987 to 2016, 26 such occurrences were recorded. Most (65%) were found by Inuvialuit hunters travelling on the land, with the majority (54%) reported during 2000–2006. Bowhead Whale carcasses were found widely distributed throughout the region, with twice as many in Amundsen Gulf (65%) compared with the southeastern Beaufort Sea (35%). It was possible to measure or estimate standard length for 17 of 26 specimens, and all were either provisional ‘subadults’ (7–9.5 m; n = 10; 59%) or provisional ‘mature adults’ (13–16 m; n = 7; 41%). The cause(s) of mortality was not determined for any of the specimens. Whales in the ‘subadult’ group were likely 1–4 years old, while the ‘mature adult’ group were likely mostly mature animals (~25 y), including some potentially very old (>100 y). There was evidence or direct observation of Polar Bears (Ursus maritimus) and/or Grizzly Bears (U. arctos) scavenging at 60% of the carcasses for which presence or absence of bears or bear sign (scats and/or tracks) was reported. It is important to continue to record incidental observations of beachcast Bowhead Whales, as this may enable stranding rates to be evaluated.

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Estimates of Bowhead Whale (Balaena Mysticetus) Numbers in the Beaufort Sea during Late Summer

ARCTIC ◽

10.14430/arctic1517 ◽

1991 ◽

Vol 44 (1) ◽

Author(s):

Sue E. Moore ◽

Janet T. Clarke

Keyword(s):

Late Summer ◽

Beaufort Sea ◽

Bowhead Whale ◽

Balaena Mysticetus

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The sounds of the bowhead whale, Balaena mysticetus, during the spring migrations of 1979 and 1980

Canadian Journal of Zoology ◽

10.1139/z84-206 ◽

1984 ◽

Vol 62 (7) ◽

pp. 1436-1441 ◽

Cited By ~ 52

Author(s):

Christopher W. Clark ◽

James H. Johnson

Keyword(s):

Spring Migration ◽

Bowhead Whale ◽

Balaena Mysticetus ◽

Underwater Sound ◽

Complex Energy ◽

Bowhead Whales ◽

Sound Direction ◽

Sound Levels ◽

Modulated Structures ◽

Summer Feeding

Bowhead whales, Balaena mysticetus, were recorded during their spring migration past Point Barrow, Alaska, in 1979 and 1980 using a pair of hydrophones linked to an underwater sound direction finding device. A great variety of sounds were recorded, including types that have been reported previously for bowheads during their spring migration, fall migration, and summer feeding. Most of the sounds were below 300 Hz with simple frequency-modulated structures. A variety of pulsive sounds were also recorded; these contained complex energy up to 3500 Hz. Sound levels of approximately 156 dB (re 1 μPa) were recorded for one whale 100–150 m from the hydrophones. We did not observe any particular behaviors which correlated with any of these sounds.

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Movements and Inferred Foraging by Bowhead Whales in the Canadian Beaufort Sea during August and September, 2006–12

ARCTIC ◽

10.14430/arctic4648 ◽

2017 ◽

Vol 70 (2) ◽

pp. 161 ◽

Cited By ~ 12

Author(s):

Lois A. Harwood ◽

Lori T. Quakenbush ◽

Robert J. Small ◽

J. Craig George ◽

James Pokiak ◽

...

Keyword(s):

Canadian Arctic ◽

Late Summer ◽

Beaufort Sea ◽

Bowhead Whale ◽

Shallow Waters ◽

Bowhead Whales ◽

Location Data ◽

State Switching ◽

Photographic Evidence ◽

Density Contour

Each spring, most bowhead whales of the Bering-Chukchi-Beaufort (BCB) population migrate to the southeast Beaufort Sea and summer in Canadian waters. In August and September, they form aggregations, which are known to occur mainly in the shallow, shelf waters when oceanographic conditions promote concentration of their zooplankton prey. The movements of individual bowheads while they occupy these late summer habitats are less well known; our knowledge is based on photographic evidence and limited tagging studies conducted from 1982 to 2000. In this study, 85% (17) of the 20 satellite-tagged whales that could have spent some time in the Canadian portion of the Beaufort Sea during late summer 2006 to 2012 spent all or part of August and September there. We analyzed location data for 16 whales, using a two-state switching correlated random walk (CRW) behavioural model, and classified locations in the Canadian waters as associated with lingering behaviour (inferred foraging) or directed travel. We found that these whales spent the greatest proportion of their time lingering (59%), followed by traveling (22%), and transitioning between lingering and traveling (19%). Using only lingering locations for these tagged whales in all study years pooled, we calculated kernel densities and defined five areas within the 75% density contour as aggregation areas. Together, the five aggregation areas we defined comprised 25 341 km2, 14.1% of the total area used by these tagged whales in Canadian waters during August and September of the deployment years. Three aggregation areas were located in shallow waters of the Beaufort Sea Shelf and were used almost exclusively by immature tagged whales in our sample. Two other aggregation areas were observed, one in Darnley Bay and one in Viscount Melville Sound in the Canadian Arctic Archipelago. Each of these was used by one mature whale. Tagged whales were observed to use one or two aggregation areas in a single season, and rarely more. The proportion of lingering time spent in each aggregation area was highly variable among individuals. The largest aggregation area (10 877 km2), located over the Beaufort Shelf north of the Tuktoyaktuk Peninsula (5 – 52 m depth), was used by 13 of the 16 tagged whales, almost exclusively by the immature whales, including three of four that were tracked in two consecutive summers. The Beaufort Shelf overall (and possibly the Tuktoyaktuk Shelf, including the Outer Shelf, in particular) was especially important for immature bowhead whales, while mature whales used habitats beyond the Beaufort Shelf during late summer. Findings may be important to inform both decisions on management and mitigative actions relating to bowhead whale use of the Beaufort Shelf and studies that aim to improve our understanding of the prey base of BCB bowhead whales in the Canadian Beaufort Sea region.

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Spatial components of bowhead whale (Balaena mysticetus) distribution in the Alaskan Beaufort Sea

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-196 ◽

2000 ◽

Vol 57 (11) ◽

pp. 2193-2200 ◽

Cited By ~ 14

Author(s):

R S Schick ◽

D L Urban

Keyword(s):

Spatial Analysis ◽

Beaufort Sea ◽

Bowhead Whale ◽

Oil Exploration ◽

Balaena Mysticetus ◽

Bowhead Whales ◽

Drilling Rig ◽

Mantel Tests ◽

Marine Realm ◽

Drilling Rigs

Bowhead whales (Balaena mysticetus) on their fall migration are exposed to oil exploration activities in the Alaskan Beaufort Sea. While previous research into the effect of industrial noise on whale behavior and distribution has noted significant responses, this research has often proceeded from a parametric statistical framework. To account for the presence of spatially autocorrelated and intercorrelated data, we propose a suite of spatial analysis techniques to assess the distribution of bowhead whales relative to oil exploration activities. Using random resampling techniques and Mantel tests, we analyzed the distribution of bowhead whales around active drilling rigs in 1993. Results from the resampling tests indicated that whales were distributed farther from the drilling rig than they would be under a random scenario. Results from the Mantel tests indicated that in 1993, the spatial pattern of bowhead whale distribution was highly correlated with distance from the drilling rig, indicating that the presence of the drilling rig resulted in a significant temporary loss in available habitat. These techniques offer a new perspective on spatial analysis in the marine realm.

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Mitogenomics and the genetic differentiation of contemporary Balaena mysticetus (Cetacea) from Svalbard

Zoological Journal of the Linnean Society ◽

10.1093/zoolinnean/zlaa082 ◽

2020 ◽

Author(s):

Lutz Bachmann ◽

Andrea A Cabrera ◽

Mads Peter Heide-Jørgensen ◽

Olga V Shpak ◽

Christian Lydersen ◽

...

Keyword(s):

Genetic Differentiation ◽

High Throughput Sequencing ◽

Demographic History ◽

Bowhead Whale ◽

Recent Common Ancestor ◽

Mitochondrial Genomes ◽

Balaena Mysticetus ◽

Bowhead Whales ◽

Most Recent Common Ancestor ◽

Loop Region

Abstract Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype and nucleotide diversities were similar to those estimated earlier for other bowhead whale populations. The reconstructed demographic history was in accordance with a boom–bust scenario, combining a slight Pleistocene population growth 25 000–35 000 years ago and a Holocene decline. Employing a mutation rate of 3.418 × 10–8 substitutions per site per year, the time to the most recent common ancestor for the mitochondrial genomes of the contemporary Svalbard bowhead whales was estimated to be 68 782 (54 353–83 216) years before the present. Based on 370 bp fragments of the D-loop region, significant genetic differentiation was detected between all extant bowhead whale populations across the circumpolar Arctic. Thus, the Svalbard bowhead whales can be regarded as a population with its own genetic legacy.

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