Frequent Questions: 2016–2023 Humpback Whale Atlantic Coast Unusual Mortality Event

What is an Unusual Mortality Event?

An unusual mortality event, or UME for short, is defined under the Marine Mammal Protection Act as a stranding event that is unexpected, involves a significant die-off of any marine mammal population, and demands immediate response. There are seven criteria that make a mortality event "unusual." If the national Working Group on Marine Mammal Unusual Mortality Events, a group of marine mammal health experts, determines that an event meets one or more of the criteria, then it forwards a recommendation to NOAA’s Assistant Administrator for Fisheries to declare a UME.

What criteria have been met for the humpback whale UME?

In the case of humpback whale strandings on the Atlantic coast, the working group concluded that criteria 1 and 2 of the seven criteria for determining an unusual mortality event have been met. Criteria 1 states that these mortalities are unusual because there is “a marked increase in the magnitude or a marked change in the nature of morbidity, mortality, or strandings when compared with prior records," and criteria 2 states that "a temporal change in morbidity, mortality, or strandings is occurring."

How widespread is this humpback whale UME?

Currently, increased mortalities of humpback whales have been observed along the Atlantic coast from Maine through Florida.

When did the first reports of increased strandings of humpback whales occur?

The first reported stranding in this event was on January 15, 2016, when a dead humpback whale was reported off Virginia Beach, Virginia. Humpback whale strandings have continued to the present.

What are the findings in stranded humpback whales?

We have not been able to retrieve many of the stranded carcasses because they were in states of advanced decomposition or were floating, but we have conducted partial or full necropsy examinations on approximately half of the 42 cases that occurred through April 2017. Of the 20 cases examined through April, 10 cases had evidence of blunt force trauma or pre-mortem propeller wounds indicative of vessel strike, which is over six times more than the 16-year average of 1.5 whales showing signs of vessel strike in this region. During this UME, vessel strikes have been documented in Virginia (3), New York (3), Delaware (2), Massachusetts (1), and New Hampshire (1).

Many humpback mortalities were caused by vessel interactions. What is being done so this does not continue to happen?

NOAA Fisheries and its stranding network partners are investigating environmental conditions and monitoring the humpback whale population to better understand how the recent mortalities occurred. Gross necropsy examinations reveal internal injuries and external wounds (propeller cuts) consistent with vessel interactions. At this time, we do not know the size of the vessel that each whale interacted with before its death. Therefore, NOAA Fisheries considers all vessel sizes to be risks for whale species in highly trafficked areas.

What kind of rules are in place for commercial and larger vessel traffic to prevent humpback mortalities?

Ship speed reduction rules are in effect during high concentrations of right whales. These rules require vessels greater than or equal to 65 feet in length to reduce speeds to 10 knots or less while entering or departing ports. While this rule was put into place primarily for the right whale presence in New England and Mid-Atlantic waters, it does benefit other whale species—including humpbacks—that are in those areas from November through July. NOAA Fisheries is reviewing ship-tracking data to ensure vessels comply with the ship speed reduction rule around Cape Cod, New York, and the Chesapeake Bay areas.

What can recreational boaters do to prevent mortalities?

We remind boaters in coastal waters throughout the region to keep a close eye out for feeding whales and to remember to follow safe viewing guidelines, which include staying 100 feet away from the whales for your safety and theirs.

What is NOAA Fisheries doing to learn more about vessel interactions?

NOAA Fisheries is consulting with researchers who are studying the humpback whale populations. Current research efforts may provide information on changes in the whale distribution and habitat use, which could provide additional insight into how these vessel interactions occurred.

Have other marine mammals or animals been affected by this UME?

To our knowledge, no other animals have been impacted during this event.

What is the current humpback whale population along the Atlantic coast?

The best estimate for the number of humpback whales that reside in the North Atlantic Ocean, including U.S. Atlantic coastal waters, is 10,400 to 10,752 animals. This estimate is based on a  1992–1993 international study of North Atlantic humpback whales across their known range. The best available estimate of the average rate of increase for the breeding population is 3.1 percent per year for the period 1979–1993 (Stevick et al. 2003). Recently, NOAA Fisheries issued a final determination to revise the listing status of the humpback whale under the Endangered Species Act. NOAA Fisheries divided the globally listed endangered species into 14 distinct population segments (DPSs), removed the current species-level listing, and determined each DPS's status for listing. The West Indies DPS, which includes the humpback whales found along the U.S. Atlantic coast, did not warrant listing. Therefore, NOAA Fisheries did not include the West Indies DPS on the endangered species list, but the population is being monitored under a 10-year post-delisting monitoring plan.

What are the next steps in the investigation now that an UME has been declared?

As part of the UME investigation process, an independent team of scientists (investigative team) is being assembled to coordinate with the working group to review the data collected and determine potential next steps.  The investigative team will develop an investigative plan and coordinate with other ongoing UME investigations. The investigation may require months, or even years of data collection, analysis, and interpretation.

What additional resources are now available to pursue the investigation, since an UME has been declared?

An UME declaration provides additional expertise from the working group (an international and multidisciplinary team of scientists) and additional stranding response partners, as well as access to additional funding through the National UME Contingency Fund.  In addition, a detailed investigative plan will be developed that may include more targeted necropsies; further testing of samples for biotoxins, bacterial or viral agents; and diagnostic pathology services. Finally, through the UME process all finding and interpretations undergo national and international scientific review.

Will you be collecting additional biological and environmental information?

Stranding network partners will continue to collect and analyze samples as needed to evaluate the situation. The working group will decide whether additional information is needed. 

When will you have some results to share?

The investigative team will begin developing an investigative plan in the next few months. You can track the progress of our investigation from our main UME webpage.

What is the risk to humans?

Large whales are wild animals and may injure people if approached closely.

Are there any risks to pets?

Pets should always be kept away from marine mammals, particularly diseased or dead marine mammals.

How many humpback whale UMEs have previously occurred along the Atlantic coast?

Three previous UMEs involving humpback whales have occurred since 2000—in 2003, 2005, and 2006. The 2003 and 2006 events primarily involved humpback whales, with 16 and 48 humpback mortalities respectively. The 2005 event involved multiple cetacean species, including seven humpback whales. Causes of the three UMEs were undetermined.

Where can I find additional information on humpback whales and other UMEs?

You can find more information on our humpback whales webpage and UME webpage.

What should people do if they encounter a dead, large whale floating or stranded on the beach?

Please immediately contact your local stranding network or local authorities to report a live or dead stranded whale:

• From Maine to Virginia, call (866) 755-NOAA (6622).
• From North Carolina to Florida, call (877) 433-8299.
• Don’t allow pets to approach the whale.
• Observe the animal from a safe distance of 100 yards (safe for you and the animal).

What can I do to help the humpback whale UME investigation?

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. Call the Greater Atlantic Marine Mammal Stranding Hotline at (866) 755-6622 or 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 the whale.

Additionally, the public may use Pay.gov to donate to the UME Contingency Fund for this or other UMEs and help cover costs incurred by the Marine Mammal Stranding Network.

What should people do if they witness harassment of a whale in the water or on the beach?

To report violations, please contact NOAA’s Office of Law Enforcement at (800) 853-1964.

What is the UME Contingency Fund?

MMPA section 405 (16 USC 1421d) establishes the Marine Mammal Unusual Mortality Event Fund, describing its purposes and how the public can donate to the fund. According to the MMPA, the fund “shall be available only for use by the Secretary of Commerce, in consultation with the Secretary of the Interior:

• To compensate persons for special costs incurred in acting in accordance with the contingency plan issued under section 1421c(b) of this title or under the direction of an Onsite Coordinator for an unusual mortality event.
• For reimbursing any stranding network participant for costs incurred in preparing and transporting tissues collected with respect to an unusual mortality event for the Tissue Bank.
• For care and maintenance of marine mammal seized under section 1374(c)(2)(D) of this title.”

The National Contingency Plan for Response to Unusual Marine Mammal Mortality Events outlines the types of expenses that are reimbursable under the fund and the process for requesting reimbursement.

Learn more about the UME Contingency Fund

How can deposits be made into the UME Contingency Fund?

The following can be deposited into the fund:

• Amounts appropriated to the fund.
• Other amounts appropriated to the Secretary for use with respect to UMEs.
• Amounts received by the United States in the form of gifts, devises, and bequests under subsection (d) of section 405(d) of the MMPA.

The public may use Pay.gov to donate to the UME Contingency Fund for this or other UMEs and help cover costs incurred by the Marine Mammal Stranding Network.