Beluga whales in the western Beaufort Sea: Current state of knowledge on timing, distribution, habitat use and environmental drivers

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 collected in the same area from 1982 to 1991. Both species are ice-adapted, migrating through leads in sea ice in spring, and are seasonal inhabitants of the western Beaufort Sea during summer and fall. From 2009 to 2016, bowheads were seen in all survey months, with the highest overall sighting rate (whales per km) in August. Bowhead sighting rates were highest in the whales’ preferred habitats: outer shelf habitat (51–200 m depth) in July and inner shelf-shallow habitat (≤ 20 m depth) in August, September, and October. Beluga whales were also seen in all survey months, with highest overall sighting rate in July. Beluga whales were overwhelmingly associated with continental slope habitat (201–2000 m depth) in all months. Bowhead distribution and depth preferences in summer months of 2009–16 differed from those observed in 1982–91, when bowheads were not seen during limited survey effort in July and preferred outer continental shelf habitat in August. These differences indicate that bowhead whale preference for shallow shelf habitat now occurs earlier in summer than it used to. Beluga distribution and depth preference remained similar between 1982–91 and 2009–16, with strong preference for continental slope during both periods. Differences in sea ice cover habitat association for both species are likely due more to the relative lack of sea ice in recent years compared to the earlier period than to shifts in habitat preference. Habitat partitioning between bowhead and beluga whales in the western Beaufort Sea remained evident except in July, when both species used continental slope habitat. In July – October 2009–16, the distribution, sighting rates, and behavior of both bowheads and belugas in the western Beaufort showed considerable interannual variation, which underscores the importance of annual sampling to accurate records of the complex western Beaufort Sea ecosystem.

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Segregation of Beaufort Sea beluga whales during the open-water season

Canadian Journal of Zoology ◽

10.1139/z06-160 ◽

2006 ◽

Vol 84 (12) ◽

pp. 1743-1751 ◽

Cited By ~ 67

Author(s):

L.L. Loseto ◽

P. Richard ◽

G.A. Stern ◽

J. Orr ◽

S.H. Ferguson

Keyword(s):

Habitat Use ◽

Sea Ice ◽

Resource Selection ◽

Open Water ◽

Beaufort Sea ◽

Reproductive Status ◽

The Arctic ◽

Habitat Segregation ◽

Beluga Whales ◽

Distance Analysis

Population segregation by habitat use occurs because energy requirements and survival strategies vary with age, sex, size, and reproductive stage. From late summer to early fall in 1993, 1995, and 1997, relative length (age), sex, and reproductive status of satellite-tagged beluga whales ( Delphinapterus leucas (Pallas, 1776)) in the eastern Beaufort Sea were tested for habitat segregation. We used (i) resource selection function models to evaluate how belugas used areas of varying sea ice concentration and shelf habitat and (ii) distance analysis to measure the selection of areas varying in distance to mainland and island coastlines. Resource selection functions and distance analysis established that habitat selection differed with length, sex, and reproductive status of whales: (i) females with calves and smaller males selected open-water habitats near the mainland; (ii) large males selected closed sea ice cover in and near the Arctic Archipelago; and (iii) smaller males and two females with calves (not newborn) selected habitat near the ice edge. The segregation of habitat use according to sex, age, and reproductive status relates to the different resources required at different life stages and may represent characteristics of beluga social structure. We discuss our results in the context of two common sexual segregation hypotheses and conclude that summer habitat segregation of belugas reflects differences in foraging ecology, risk of predation, and reproduction.

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Stingray Habitat Use Is Dynamically Influenced by Temperature and Tides

Frontiers in Marine Science ◽

10.3389/fmars.2021.754404 ◽

2022 ◽

Vol 8 ◽

Author(s):

Chantel Elston ◽

Paul D. Cowley ◽

Rainer G. von Brandis ◽

James Lea

Keyword(s):

Habitat Use ◽

Acoustic Telemetry ◽

Monsoon Season ◽

Abiotic Factors ◽

Environmental Drivers ◽

Shallow Waters ◽

Shallow Marine ◽

Tidal Cycles ◽

Management Plans ◽

Passive Acoustic

Abiotic factors often have a large influence on the habitat use of animals in shallow marine environments. Specifically, tides may alter the physical and biological characteristics of an ecosystem while changes in temperature can cause ectothermic species to behaviorally thermoregulate. Understanding the contextual and relative influences of these abiotic factors is important in prioritizing management plans, particularly for vulnerable faunal groups like stingrays. Passive acoustic telemetry was used to track the movements of 60 stingrays at a remote and environmentally heterogeneous atoll in Seychelles. This was to determine if habitat use varied over daily, diel and tidal cycles and to investigate the environmental drivers behind these potential temporal patterns. Individuals were detected in the atoll year-round, but the extent of their movement and use of multiple habitats increased in the warmer NW-monsoon season. Habitat use varied over the diel cycle, but was inconsistent between individuals. Temperature was also found to influence stingray movements, with individuals preferring the deeper and more thermally stable lagoon habitat when extreme (hot or cold) temperature events were observed on the flats. Habitat use also varied over the tidal cycle with stingrays spending a higher proportion of time in the lagoon during the lowest tides, when movement on the flats were constrained due to shallow waters. The interplay of tides and temperature, and how these varied across diel and daily scales, dynamically influenced stingray habitat use consistently between three species in an offshore atoll.

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Environmental drivers of habitat use by a marine fish on a heterogeneous and dynamic reef flat

Marine Biology ◽

10.1007/s00227-018-3464-2 ◽

2019 ◽

Vol 166 (2) ◽

Cited By ~ 6

Author(s):

Jacob W. Brownscombe ◽

Lucas P. Griffin ◽

Tyler O. Gagne ◽

Christopher R. Haak ◽

Steven J. Cooke ◽

...

Keyword(s):

Habitat Use ◽

Marine Fish ◽

Reef Flat ◽

Environmental Drivers

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Habitat Use and Foraging Patterns of Molting Male Long-tailed Ducks in Lagoons of the Central Beaufort Sea, Alaska

ARCTIC ◽

10.14430/arctic4544 ◽

2016 ◽

Vol 69 (1) ◽

pp. 19

Author(s):

Paul L. Flint ◽

John A. Reed ◽

Deborah L. Lacroix ◽

Richard B. Lanctot

Keyword(s):

Home Range ◽

Habitat Use ◽

Beaufort Sea ◽

Home Range Size ◽

Oil Field ◽

Range Size ◽

Foraging Habitat ◽

Field Development ◽

Industrial Oil ◽

Radio Transmitters

From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (<em>Clangula hyemalis</em>) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.

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Zones of impact around icebreakers affecting beluga whales in the Beaufort Sea

The Journal of the Acoustical Society of America ◽

10.1121/1.1288938 ◽

2000 ◽

Vol 108 (3) ◽

pp. 1332 ◽

Cited By ~ 34

Author(s):

Christine Erbe ◽

David M. Farmer

Keyword(s):

Beaufort Sea ◽

Beluga Whales

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Spring conditions and habitat use of beluga whales (Delphinapterus leucas) during arrival to the Mackenzie River Estuary

Polar Biology ◽

10.1007/s00300-016-1899-9 ◽

2016 ◽

Vol 39 (12) ◽

pp. 2319-2334 ◽

Cited By ~ 10

Author(s):

Claire A. Hornby ◽

Carie Hoover ◽

John Iacozza ◽

David G. Barber ◽

Lisa L. Loseto

Keyword(s):

Habitat Use ◽

River Estuary ◽

Delphinapterus Leucas ◽

Beluga Whales ◽

Mackenzie River

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

PLoS ONE ◽

10.1371/journal.pone.0253929 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0253929

Author(s):

Kathleen M. Stafford ◽

John J. Citta ◽

Stephen R. Okkonen ◽

Jinlun Zhang

Keyword(s):

Sea Ice ◽

Environmental Changes ◽

Beaufort Sea ◽

Zooplankton Biomass ◽

Beluga Whale ◽

Environmental Drivers ◽

Cetacean Species ◽

Sea Transport ◽

Bowhead Whales ◽

Acoustic Data

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.

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Ocean-entry timing and marine habitat-use of Canadian Dolly Varden: Dispersal among conservation, hydrocarbon exploration, and shipping areas in the Beaufort Sea

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2021.107609 ◽

2021 ◽

pp. 107609

Author(s):

Colin P. Gallagher ◽

Michael B. Courtney ◽

Andrew C. Seitz ◽

Ellen V. Lea ◽

Kimberly L. Howland

Keyword(s):

Habitat Use ◽

Beaufort Sea ◽

Hydrocarbon Exploration ◽

Dolly Varden ◽

Marine Habitat ◽

Entry Timing

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Year-Round Dive Characteristics of Male Beluga Whales From the Eastern Beaufort Sea Population Indicate Seasonal Shifts in Foraging Strategies

Frontiers in Marine Science ◽

10.3389/fmars.2021.715412 ◽

2022 ◽

Vol 8 ◽

Author(s):

Luke Storrie ◽

Nigel E. Hussey ◽

Shannon A. MacPhee ◽

Greg O’Corry-Crowe ◽

John Iacozza ◽

...

Keyword(s):

Annual Cycle ◽

Environmental Variables ◽

Marine Mammals ◽

Beaufort Sea ◽

Optimal Foraging Theory ◽

Sampling Interval ◽

Foraging Strategies ◽

Vertical Movements ◽

Beluga Whales ◽

Seasonal Shifts

Dive behavior represents multiple ecological functions for marine mammals, but our understanding of dive characteristics is typically limited by the resolution or longevity of tagging studies. Knowledge on the time-depth structures of dives can provide insight into the behaviors represented by vertical movements; furthering our understanding of the ecological importance of habitats occupied, seasonal shifts in activity, and the energetic consequences of targeting prey at a given depth. Given our incomplete understanding of Eastern Beaufort Sea (EBS) beluga whale behavior over an annual cycle, we aimed to characterize dives made by belugas, with a focus on analyzing shifts in foraging strategies. Objectives were to (i) characterize and classify the range of beluga-specific dive types over an annual cycle, (ii) propose dive functions based on optimal foraging theory, physiology, and association with environmental variables, and (iii) identify whether belugas undergo seasonal shifts in the frequency of dives associated with variable foraging strategies. Satellite-linked time-depth-recorders (TDRs) were attached to 13 male belugas from the EBS population in 2018 and 2019, and depth data were collected in time series at a 75 s sampling interval. Tags collected data for between 13 and 357 days, including three tags which collected data across all months. A total of 90,211 dives were identified and characterized by twelve time and depth metrics and classified into eight dive types using a Gaussian mixed modeling and hierarchical clustering analysis approach. Dive structures identify various seasonal behaviors and indicate year-round foraging. Shallower and more frequent diving during winter in the Bering Sea indicate foraging may be energetically cheaper, but less rewarding than deeper diving during summer in the Beaufort Sea and Arctic Archipelago, which frequently exceeded the aerobic dive limit previously calculated for this population. Structure, frequency and association with environmental variables supports the use of other dives in recovery, transiting, and navigating through sea ice. The current study provides the first comprehensive description of the year-round dive structures of any beluga population, providing baseline information to allow improved characterization and to monitor how this population may respond to environmental change and increasing anthropogenic stressors.

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