Baleen whales in the cross hairs: potential for increased ship strike risk in and near Bering Strait


March 2022 Article Update: Watch a newly released video on this topic here.


Currently trans-Arctic shipping is conducted along the Northern Sea Route (NSR) and the Northwest Passage (NWP), with a Transpolar Sea Route (TSR) anticipated by mid-century1. The NSR, which extends from the Barents Sea to the Bering Sea, is roughly 40% shorter than commercial sea routes through the Suez Canal. Shipping along the NSR increased from 10.7 million tons in 2017 to a record-breaking 32 million tons in 20202. To date, most shipping along the NSR has occurred from July-November, with peak traffic in September coinciding with minimum annual sea ice cover. With continued loss of sea ice, commercial shipping across all routes likely will increase in terms of both rates of passage and season length, as exemplified by the first-ever voyages of liquid natural gas (LNG) tankers along the NSR in January 2021.

All trans-Arctic shipping routes converge at the narrow (85 km) and shallow (50m) Bering Strait1. To navigate safely, ships must travel along a constricted route as they approach and depart the strait, making these waters especially perilous for large whales that migrate through and feed in the area.

The migratory habits of the Arctic endemic bowhead whales (Balaena mysticetus) have kept them mostly out of harm’s way, as the Bering-Chukchi-Beaufort population of bowheads generally spends the summer months in the Beaufort Sea. Conversely, sub-arctic species including gray, humpback, fin and minke whales are now common near the Bering Strait region during summer months. One source of recent sighting data is a ‘marine mammal watch’ conducted as standard protocol during research cruises that comprise the Distributed Biological Observatory (DBO)3. Collectively, baleen whale sightings from DBO cruises conducted from July-October 2009-2019 showed the concentrated distribution of gray whales north and south of the Bering Strait, with humpback, fin and minke whales frequently seen primarily north of the strait (Figure 1). All species in the region are there principally to feed in summer, thus less likely to be responsive to oncoming ships and therefore at risk of injury or death by ship strike.


Figure 1 – Gray, Humpback, Fin and Minke whale sightings on DBO cruises, 2009-2019


A number of international efforts to mitigate risks to baleen whales from ship strike are under way, the most relevant being the Arctic Marine Shipping Assessment (AMSA), a project of the Arctic Council PAME Working Group4. Goals of the AMSA are bolstered by work in both the Conservation and Scientific Committees of the International Whaling Commission (IWC) to reduce ship strikes on baleen whales worldwide5. To support the goals of these international organizations, the marine mammal sightings initiative of the DBO should be expanded to include experienced observers on more research and commercial ships passing through Bering Strait. This effort to increase visual sightings should be coordinated with passive acoustic detection efforts in near real-time to better mitigate ship-whale interactions. At present, such multi-faceted ship strike mitigation efforts are focused solely on endangered species at busy ports (e.g., North Atlantic right whales in Boston Harbor), but existing technologies could and should be brought to the Bering Strait gateway soon.








Vaquita update October through December 2020

Searching for vaquitas through the Sea Shepherd Conservation Society’s newly purchased ‘big eye’ binoculars. This specialized scientific equipment is part of an increasing scientific conservation effort by SSCS.


Despite the many challenges presented throughout an exceptionally difficult year, a few vaquitas continue to survive. Cooperative fishermen who participate in the vaquita acoustic monitoring program deployed detectors from September 7 to 12 of 2020 in the Zero Tolerance Area (‘Critical Zone’ on the map figures). A total of nine acoustic encounters were recorded. In a joint effort with the National Commission for Natural Protected Areas, Sea Shepherd Conservation Society (SSCS) sponsored a downsized visual survey effort from the SSCS ship in November 2020 with two experienced observers from previous vaquita surveys. Despite this small expedition being challenged by unfavorable weather conditions and a vast number of pangas present, two separate sightings of vaquitas were made during the 8 days of limited effort.


A group of pangas with gillnets on full display in daytime despite this gear being illegal within vaquita habitat. Credit: Sea Shepherd Conservation Society

SSCS deployed 2 ships to attempt to safeguard vaquita habitat. Efforts focused on the Zero Tolerance Area, but all panga activity within range of radar units was recorded. Illegal fishing increased with the onset of shrimp season in October 2020 (Figure 1). The vaquita sightings were obtained despite the presence of 1185 pangas that were counted throughout November, with the most observed simultaneously being over 60 (Figure 2). Nearly all of these pangas were gillnetting for shrimp.

The Government of Mexico arrested some of the leaders of totoaba poaching who are now waiting in jail to go to trial. Despite these arrests, illegal fishing remains at high levels and takes place day and night (Figure 3), with repeated harassment of net-removal crews.


Figure 1. Panga positions in October 2020 where each color represents the approximate number of pangas observed from the survey vessel at a given time and location. Yellow dots indicate individual pangas that were confirmed to be fishing. SSCS effort was concentrated in the Zero Tolerance Area (outlined in red but labeled as the ‘Critical Zone’ in the map legend). Source: Sea Shepherd Conservation Society Internal reports, October 2020

Figure 2. Panga positions in November 2020 where each color represents the approximate number of pangas observed at a given time. Effort by net-removal vessels that reported panga positions was concentrated in the Zero Tolerance Area (outlined in red but labeled as the ‘Critical Zone’ in the map legend). Source: Sea Shepherd Conservation Society Internal reports, November 2020

Figure 3. Panga positions in December 2020 where each color represents the approximate number of pangas observed at a given time. Effort was concentrated in the Zero Tolerance Area (outlined in red but labeled as the ‘Critical Zone’ in the map legend) but fishing was observed widely in the Vaquita Refuge (inset). Source: Sea Shepherd Conservation Society Internal reports, December 2020


Fishermen have no incentives to change their traditional fishing practices – very little alternative fishing gear, and few alternative livelihoods to feed their families. Illegal fishing remains uncontrolled. There were no net-removal efforts at the end of the last totoaba season (May 2020) due to SSCS and the Museo de Ballena having to leave the area on 22nd March due to the evolving global pandemic, which hit the Mexican villages of San Felipe and El Golfo de Santa Clara very hard. Many fishermen and their families became infected. We especially honor Paco Valverede who succumbed to the virus. Paco learned from his father and his family of fishermen how to fish and he loved and respected the ocean. He studied biology but always remained faithful to his origins as a fisherman. He fought long and hard for conservation of marine life and environmentally responsible fisheries in the Upper Gulf of California. Those who knew and worked with him considered Paco indispensable and irreplaceable, a true hero and a friend of vaquitas. For more details, see

22 Updated Cetacean Red List Assessments Published in December 2020


Between 2018 and 2020, the Cetacean Specialist Group has undertaken a re-assessment of all cetacean species, a task that is now virtually complete. The 2020-3 edition of the Red List, which was published in December 2020, included 22 assessments or re-assessments of cetacean species, subspecies or populations and included almost all of the beaked whales. This is in addition to 3 assessments published earlier in 2020, 6 in December 2019, 2 in July 2019, 5 in March 2019, 35 in November 2018, 10 in July 2018, and 19 in November 2017. A total of 102 updated or new cetacean assessments have been published in the last 2 ½ years.


The updated assessments included almost all of the beaked whales many of which moved out of the Data Deficient category to Least Concern, while Perrin’s beaked whale (Mesoplodon perrini) is now Endangered, and Stejneger’s beaked whale (Mesoplodon stejnegeri) and a newly described species, Sato’s beaked whale (Berardius minimus), are both Near Threatened. Most of the changes for beaked whales resulted from the IUCN Guidelines changing the definition of Data Deficient and thus are not necessarily genuine changes in conservation status. To remain as Data Deficient, a species had to plausibly belong in any category from Critically Endangered to Least Concern.


Besides the beaked whales, the South American freshwater dolphin Sotalia fluviatilis, commonly known as the tucuxi, was reassessed and moved from Data Deficient to Endangered (Table 1). This change was due in large part to improved data and analyses. Re-assessments of the common dolphin (Delphinus delphis) and northern bottlenose whale (Hyperoodon ampullatus) will be published in the next Red List edition in 2021. Work on the two cetacean species that still require reassessment, and on some of the more out of date subpopulation and subspecies assessments, will begin in 2021.


Table 1. Summary of updated assessments and new assessments published in the 2020-3 edition of the Red List. (NT = Near Threatened, DD = Data Deficient, CR = Critically Endangered, EN = Endangered, LC = Least Concern).

# Species/Subspecies Common name Taxonomic level Category Status change
1 Berardius arnuxii Arnoux’s beaked whale Species (global) LC DD -> LC
2 Berardius bairdii Baird’s beaked whale Species (global) LC DD -> LC
3 Berardius minimus Sato’s beaked whale Species (global) NT New listing
4 Hyperoodon planifrons Southern bottlenose whale Species (global) LC No change
5 Indopacetus pacificus Longman’s beaked whale Species (global) LC DD -> LC
6 Mesoplodon bidens Sowerby’s beaked whale Species (global) LC DD -> LC
7 Mesoplodon bowdoini Andrews’ beaked whale Species (global) DD No change
8 Mesoplodon carlhubbsi Hubbs’ beaked whale Species (global) DD No change
9 Mesoplodon densirostris Blainville’s beaked whale Species (global) LC DD -> LC
10 Mesoplodon europaeus Gervais’ beaked whale Species (global) LC DD -> LC
11 Mesoplodon ginkgodens Ginkgo-toothed beaked whale Species (global) DD No change
12 Mesoplodon grayi Gray’s beaked whale Species (global) LC DD -> LC
13 Mesoplodon hectori Hector’s beaked whale Species (global) DD No change
14 Mesoplodon hotaula Deraniyagala’s beaked whale Species (global) DD No change
15 Mesoplodon layardii Strap-toothed beaked whale Species (global) LC DD -> LC
16 Mesoplodon mirus True’s beaked whale Species (global) LC DD -> LC
17 Mesoplodon perrini Perrin’s beaked whale Species (global) EN DD -> EN
18 Mesoplodon peruvianus Pygmy beaked whale Species (global) LC DD -> LC
19 Mesoplodon stejnegeri Stejneger’s beaked whale Species (global) NT DD -> NT
20 Mesoplodon traversii Spade-toothed beaked whale Species (global) DD No change
21 Sotalia fluviatilis Tucuxi Species (global) EN DD -> EN
22 Ziphius cavirostris Cuvier’s beaked whale Species (global) LC No change


The Red List status and documentation for 90 cetacean species as well as 12 subspecies and 28 subpopulations can be found on the IUCN Red List website ( Of the 90 species, 24% are assigned to a threatened category (i.e., CR, EN, VU) and 11% are considered DD (Table 2). It should also be emphasized that there is strong interest in completing additional assessments of subpopulations that are known or thought to be at higher risk than the species as a whole (e.g., Killer Whales, Belugas, Dusky Dolphins).


Table 2. Summary information on Red List status as of December 2020.

Category Species Subspecies Subpopulations Total
Critically Endangered 4 4 14 22
Endangered 11 4 7 22
Vulnerable 7 4 5 16
Near Threatened 9 0 0 9
Least Concern 49 0 0 49
Data Deficient 10 0 2 12
Total 90 12 28 130