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2017–2023 North Atlantic Right Whale Unusual Mortality Event
Since 2017, dead, seriously injured, or sublethally injured or ill North Atlantic right whales have been documented, necessitating an Unusual Mortality Event declaration and investigation.
Beginning in 2017, elevated mortalities in North Atlantic right whales (Eubalaena glacialis) were documented in Canada and the United States and necessitated an Unusual Mortality Event (UME) be declared. The whales impacted by the UME include dead, injured, and sick individuals, who represent more than 20 percent of the population, which is a significant impact on an endangered species where deaths are outpacing births. Additionally, research demonstrates that only about 1/3 of right whale deaths are documented. The preliminary cause of mortality, serious injury, and morbidity (sublethal injury and illness) in most of these whales is from entanglements or vessel strikes. Given that the latest preliminary estimate suggests there are fewer than 350 North Atlantic right whales remaining, the many individual whales involved in the UME are a significant setback to the recovery of this endangered species.
Counts of North Atlantic Right Whale UME Mortality, Serious Injury, and Morbidity (Sublethal Injury or Illness) Cases
Annual North Atlantic Right Whale Mortalities by Cause of Death, 2017-2023
Annual North Atlantic Right Whale Serious Injury (SI) Cases of Whales Last Seen Alive, 2017-2023
Annual North Atlantic Right Whale Morbidity (Sublethal Injury/Illness) Cases, 2017-2023
Serious Injury and Morbidity
Serious injury determination is a detailed scientific assessment process. It uses health data, such as body condition and parameters of the human-caused injury, collected from living whales to determine an individual whale’s prognosis for survival. A serious injury designation indicates a whale is likely to die from those injuries (although it was alive at its last sighting).
Morbidity determination is also a detailed scientific and veterinary assessment process that uses health data to assess sublethal injury or illness. These whales are evaluated from photos or videos. For the right whale UME, the morbidity (sublethal injury or illness) classification categories reflect: vessel strikes, entanglements, and injuries or poor body condition of unknown cause.
Causes of the North Atlantic Right Whale UME
The leading cause of this UME is human interaction, specifically from entanglements or vessel strikes. Necropsy (animal autopsy) results are available from seven of the Canadian whales from 2017 and from five of the whales from 2019. Photos and other available documentation for the live whales were reviewed by NOAA Fisheries’ Northeast Fisheries Science Center as part of the serious injury determination process and by internal and external reviewers as part of the morbidity (sublethal injury or illness) process (see tables below for details on specific animals and findings).
The most important step that the public can take to assist investigators is to immediately report any sightings of injured or stranded whales (dead or alive). In the United States, call the Greater Atlantic Marine Mammal Stranding Hotline at (866) 755-6622 or the Southeast Marine Mammal Stranding Hotline at (877) 433-8299.
In Canada, call the Marine Animal Response Society at (866) 567-6277 or the Quebec Marine Mammal Emergency Response Network at (877) 722-5346.
You can also contact the U.S. and Canadian Coast Guards on VHF Channel 16. Do not approach injured or dead animals.
North Atlantic right whale Catalog #3560 ‘Snow Cone’ sighted December 2, 2021 entangled and with a new calf. Photo credit: Florida Fish and Wildlife Conservation Commission taken under NOAA permit 20556.
North Atlantic right whale Catalog #3560 ‘Snow Cone’ sighted December 2, 2021 entangled and with a new calf. Photo credit: Florida Fish and Wildlife Conservation Commission taken under NOAA permit 20556.
Four North Atllantic right whales.
A Northeast Fisheries Science Center biologist collecting data during buoyless lobster trap tests.
North Atlantic right whale mother and calf. Credit: Clearwater Marine Aquarium Research Institute, taken under NOAA permit #20556-01.