Future seasonal changes in habitat for Arctic whales during predicted ocean warming

Chambault, Philippine; Kovacs, Kit M.; Lydersen, Christian; Шпак, О. В.; Teilmann, Jonas; Albertsen, Christoffer Moesgaard; Heide‐Jørgensen, Mads Peter

doi:10.1126/sciadv.abn2422

Cited by 21 publications

(21 citation statements)

References 44 publications

(58 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although there was no long-term trend in annual southward or northward passage through the Bering Strait, there was a stepwise shift (i.e., decline) in whale absence from the southern Chukchi Sea during the southward and northward passage across 9 migratory seasons. Chambault et al [ 62 ] predicted northward shifts in Eastern Arctic bowhead whale distribution to cope with climate change. The reduced absence between southward and northern migration through the Bering Strait from our findings supports this, and suggests BCB bowhead whales are shifting northward, potentially overwintering in the southern Chukchi Sea.…”

Section: Discussionmentioning

confidence: 99%

Sea ice directs changes in bowhead whale phenology through the Bering Strait

Szesciorka

Stafford

2023

Mov Ecol

View full text Add to dashboard Cite

Background Climate change is warming the Arctic faster than the rest of the planet. Shifts in whale migration timing have been linked to climate change in temperate and sub-Arctic regions, and evidence suggests Bering–Chukchi–Beaufort (BCB) bowhead whales (Balaena mysticetus) might be overwintering in the Canadian Beaufort Sea. Methods We used an 11-year timeseries (spanning 2009–2021) of BCB bowhead whale presence in the southern Chukchi Sea (inferred from passive acoustic monitoring) to explore relationships between migration timing and sea ice in the Chukchi and Bering Seas. Results Fall southward migration into the Bering Strait was delayed in years with less mean October Chukchi Sea ice area and earlier in years with greater sea ice area (p = 0.04, r2 = 0.40). Greater mean October–December Bering Sea ice area resulted in longer absences between whales migrating south in the fall and north in the spring (p < 0.01, r2 = 0.85). A stepwise shift after 2012–2013 shows some whales are remaining in southern Chukchi Sea rather than moving through the Bering Strait and into the northwestern Bering Sea for the winter. Spring northward migration into the southern Chukchi Sea was earlier in years with less mean January–March Chukchi Sea ice area and delayed in years with greater sea ice area (p < 0.01, r2 = 0.82). Conclusions As sea ice continues to decline, northward spring-time migration could shift earlier or more bowhead whales may overwinter at summer feeding grounds. Changes to bowhead whale migration could increase the overlap with ships and impact Indigenous communities that rely on bowhead whales for nutritional and cultural subsistence.

show abstract

Section: Discussionmentioning

confidence: 99%

Sea ice directs changes in bowhead whale phenology through the Bering Strait

Szesciorka

Stafford

2023

Mov Ecol

View full text Add to dashboard Cite

show abstract

“…In summer, narwhals are both niche-conservative and cold-adapted with a preferred feeding temperature of less than 2°C [ 31 ], yet climate change promotes warmer sea temperatures on their summer grounds [ 32 ] as well as the predicted disappearance of their winter habitat [ 33 ]. Our findings, therefore, raise concerns about the strong dependence this deep-diving predator has on its winter habitat.…”

Section: Discussionmentioning

confidence: 99%

Extremely low seasonal prey capture efficiency in a deep-diving whale, the narwhal

2023

Self Cite

View full text Add to dashboard Cite

Successful foraging is essential for individuals to maintain the positive energy balance required for survival and reproduction. Yet, prey capture efficiency is poorly documented in marine apex predators, especially deep-diving mammals. We deployed acoustic tags and stomach temperature pills in summer to collect concurrent information on presumed foraging activity (through buzz detection) and successful prey captures (through drops in stomach temperature), providing estimates of feeding efficiency in narwhals. Compared to the daily number of buzzes (707 ± 368), the daily rate of feeding events was particularly low in summer (19.8 ± 8.9) and only 8–14% of the foraging dives were successful (i.e. with a detectable prey capture). This extremely low success rate resulted in a very low daily food consumption rate (less than 0.5% of body mass), suggesting that narwhals rely on body reserves accumulated in winter to sustain year-round activities. The expected changes or disappearance of their wintering habitats in response to climate change may therefore have severe fitness consequences for narwhal populations.

show abstract

“…For example, 16.9 km per decade shifts to high-latitude regions have been observed across many terrestrial species (Chen et al, 2011). Consequently, the timing of bowhead whale migration, along with their distribution and residency patterns, particularly during open water season, are likely to change overtime (Chambault et al, 2022).…”

Section: Sensitivity To Climate Changementioning

confidence: 99%

Year-round foraging across large spatial scales suggest that bowhead whales have the potential to adapt to climate change

Fortune

Trites²,

LeMay³

et al. 2023

Front. Mar. Sci.

View full text Add to dashboard Cite

The ecological impact of environmental changes at high latitudes (e.g., increasing temperature, and decreased sea ice cover) on low-trophic species, such as bowhead whales, are poorly understood. Key to understanding the vulnerability of zooplanktivorous predators to climatic shifts in prey is knowing whether they can make behavioural or distributional adjustments to maintain sufficient prey acquisition rates. However, little is known about how foraging behaviour and associated environmental conditions fluctuate over space and time. We collected long-term movement (average satellite transmission days were 397 (± 204 SD) in 2012 and 484 (± 245 SD) in 2013) and dive behaviour data for 25 bowhead whales (Balaena mysticetus) equipped with time-depth telemetry tags, and used hierarchical switching-state-space models to quantify their movements and behaviours (resident and transit). We examined trends in inferred two-dimensional foraging behaviours based on dive shape of Eastern Canada-West Greenland bowhead whales in relation to season and sea ice, as well as animal sex and age via size. We found no differences with regards to whale sex and size, but we did find evidence that subsurface foraging occurs year-round, with peak foraging occurring in fall (7.3 hrs d-1 ± 5.70 SD; October) and reduced feeding during spring (2.7 hrs d-1 ± 2.55 SD; May). Although sea ice cover is lowest during summer foraging, whales selected areas with 65% (± 36.1 SD) sea ice cover. During winter, bowheads occurred in areas with 90% (± 15.5 SD) ice cover, providing some open water for breathing. The depth of probable foraging varied across seasons with animals conducting epipelagic foraging dives (< 200 m) during spring and summer, and deeper mesopelagic dives (> 400 m) during fall and winter that approached the sea bottom, following the seasonal vertical migration of lipid-rich zooplankton. Our findings suggest that, compared to related species (e.g., right whales), bowheads forage at relatively low rates and over a large geographic area throughout the year. This suggests that bowhead whales have the potential to adjust their behaviours (e.g., increased time allocated to feeding) and shift their distributions (e.g., occupy higher latitude foraging grounds) to adapt to climate-change induced environmental conditions. However, the extent to which energetic consumption may vary seasonally is yet to be determined.

show abstract

Future seasonal changes in habitat for Arctic whales during predicted ocean warming

Cited by 21 publications

References 44 publications

Sea ice directs changes in bowhead whale phenology through the Bering Strait

Sea ice directs changes in bowhead whale phenology through the Bering Strait

Extremely low seasonal prey capture efficiency in a deep-diving whale, the narwhal

Year-round foraging across large spatial scales suggest that bowhead whales have the potential to adapt to climate change

Contact Info

Product

Resources

About