2016–2025 Humpback Whale Unusual Mortality Event Along the Atlantic Coast
Since January 2016, elevated humpback whale mortalities have occurred along the Atlantic coast from Maine through Florida.
Since January 2016, elevated humpback whale mortalities have occurred along the Atlantic coast from Maine through Florida. A table of mortalities by state is below.
This event was declared an Unusual Mortality Event in April 2017, and includes humpback whale deaths from 2016 and on.
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| Location First Observed Dead* | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | Subtotal | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maine (State) | 2 | 0 | 2 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 7 | 10 |
| Maine (Offshore**) | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 3 | |
| New Hampshire (State) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
| New Hampshire (Offshore) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Massachusetts (State) | 3 | 3 | 2 | 0 | 5 | 2 | 3 | 3 | 7 | 0 | 28 | 54 |
| Massachusetts (Offshore) | 0 | 4 | 2 | 4 | 5 | 2 | 0 | 4 | 5 | 0 | 26 | |
| Rhode Island (State) | 2 | 3 | 0 | 0 | 0 | 0 | 2 | 1 | 2 | 0 | 10 | 13 |
| Rhode Island (Offshore) | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 3 | |
| New York (State) | 4 | 4 | 7 | 3 | 6 | 1 | 2 | 7 | 2 | 0 | 36 | 47 |
| New York (Offshore) | 0 | 1 | 1 | 2 | 3 | 0 | 0 | 4 | 0 | 0 | 11 | |
| New Jersey (State) | 2 | 2 | 1 | 5 | 2 | 0 | 4 | 5 | 2 | 0 | 23 | 35 |
| New Jersey (Offshore) | 1 | 1 | 1 | 0 | 2 | 0 | 0 | 3 | 2 | 2 | 12 | |
| Maryland (State) | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 5 | 6 |
| Maryland (Offshore) | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | |
| Delaware (State) | 2 | 2 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 8 | 9 |
| Delaware (Offshore) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | |
| Virginia (State) | 0 | 5 | 2 | 4 | 1 | 1 | 1 | 4 | 2 | 0 | 20 | 34 |
| Virginia (Offshore) | 2 | 2 | 2 | 2 | 3 | 0 | 0 | 2 | 0 | 1 | 14 | |
| North Carolina (State) | 4 | 5 | 1 | 3 | 3 | 3 | 2 | 2 | 2 | 3 | 28 | 37 |
| North Carolina (Offshore) | 0 | 1 | 1 | 1 | 0 | 0 | 2 | 0 | 1 | 3 | 9 | |
| South Carolina (State) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 2 |
| South Carolina (Offshore) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | |
| Georgia (State) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 |
| Georgia (Offshore) | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 2 | 0 | 4 | |
| Florida (State) | 0 | 0 | 2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 3 | 3 |
| Florida (Offshore) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| TOTAL | 26 | 34 | 26 | 27 | 33 | 10 | 19 | 37 | 31 | 12 | 255 | 255 |
*Note: Location represents the nearest state to where the confirmed mortality was first observed and does not necessarily reflect the location of the death of the animal. Floating carcasses may drift across state border lines; therefore, a carcass may be initially sighted or reported nearest one state although the mortality may have occurred elsewhere. Additionally, an animal first observed floating may wash ashore and be examined in a different state; this table represents the closest state of the initial observation of the carcass.
**Offshore waters include waters in the U.S. Exclusive Economic Zone under Federal jurisdiction between 3nm-200nm from the coast.
Causes of the Humpback Whale UME
Partial or full necropsy examinations were conducted on approximately half of the whales. Of the whales examined (approximately 90), about 40 percent had evidence of human interaction, either ship strike or entanglement. A portion of the whales have shown evidence of pre-mortem vessel strike; however, this finding is not consistent across all whales examined. More research is needed.
As part of the UME investigation process, NOAA assembled an independent team of scientists to coordinate with the Working Group on Marine Mammal Unusual Mortality Events to review data, sample stranded whales, and determine the next steps for the investigation.
Report a Stranding
The most important step members of the public can take to assist investigators is to immediately report any sightings of live whales in distress or stranded or dead whales. Make the report by calling the Greater Atlantic Marine Mammal Stranding Hotline at (866) 755-6622, the Southeast Marine Mammal Stranding Hotline at (877) 433-8299 or contact the U.S. Coast Guard on VHF Channel 16. Do not approach or touch injured or dead marine mammals.
Dead stranded humpback whale showing evidence of pre-mortem propeller injuries. Photo: Virginia Aquarium.
Interactive Map
More Information
More Information
- Frequent Questions: 2016–2025 Humpback Whale Unusual Mortality Event
- Frequent Questions: Offshore Wind and Whales
- Media Teleconference on East Coast Whale Strandings (January 18, 2023)
- Unusual Mortality Events
- National Marine Mammal Stranding Response Network
- Marine Mammal Health and Stranding Response Program
- Marine Mammal Protection