Frequent Questions: 2018 Pinniped Unusual Mortality Event
Since July 2018, elevated numbers of harbor seal and gray seal mortalities have occurred across Maine, New Hampshire and Massachusetts. This event has been declared an Unusual Mortality Event (UME).
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 to declare the 2018 Pinniped Unusual Mortality Event?
For the 2018 Pinniped Unusual Mortality Event in the Northeast, the Working Group concluded that two of the seven criteria of UMEs have been met:
- A marked increase in the magnitude or a marked change in the nature of morbidity, mortality or strandings when compared with prior records.
- Affected animals exhibit similar or unusual pathologic findings, behavior patterns, clinical signs, or general physical condition.
How widespread is the 2018 Pinniped Unusual Mortality Event?
Increased mortalities of primarily harbor seals and fewer gray seals have been observed along the northeast coast in Maine, New Hampshire, and northern Massachusetts.
How many seals are involved in the event?
The event began on July 1, 2018. As of October 10, there have been over 1,200 confirmed individual dead and live stranded harbor and gray seals.
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 unusual mortality event 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.
What are the findings in the stranded seals?
Full or partial necropsy examinations have been conducted on some dead seals, although many were decomposed.
Based on tests conducted so far, the main pathogen found in the seals is phocine distemper virus. Phocine distemper virus is not zoonotic, which means it cannot be transferred to humans, but it may still be able to affect pets. The test results do not provide strong evidence that avian influenza virus is a cause of the current Northeast Pinniped UME.
We are continuing additional testing to identify any other factors that may be involved in this event and will share those findings when available.
What are the symptoms displayed by the seals?
In live seals, symptoms include lethargy, sneezing, coughing, discharge from the eyes and nose, seizures, skin abscesses, poor body condition and death. In dead seals, necropsy findings have confirmed respiratory disease and pneumonia.
What can I do to help the investigation into this seal UME event?
The most important step members of the public can take to assist investigators is to immediately report any sightings of seals in distress or dead stranded seals. Call the NOAA hotline at 866-755-NOAA (6622). Do not approach or touch the seal.
Where can I find additional information on harbor and gray seals?
You can also read about seal viewing guidelines in the Northeast.
What are the different types of influenza viruses and which are found in seals?
There are three types of influenza viruses: A, B, and C.
Avian influenza A viruses occasionally cross over species barriers and cause clinical diseases and epidemics in people and other mammalian species including seals.
Influenza B viruses are primarily found in people with no known wildlife reservoir, cause clinical disease, and epidemics in people; however they have been isolated from healthy gray and harbor seals the North Sea.
Influenza C is a virus that infects people and may cause a mild respiratory illness but are not thought to cause epidemics in people.
Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and the neuraminidase (N). There are 16 different hemagglutinin subtypes and nine different neuraminidase subtypes. Influenza A viruses can be further broken down into different strains. Subtypes may be species-specific so not all subtypes are found in all species. (For more information, visit the CDC website).
Both Influenza A and Influenza B have been documented to cause illness in seals in North America and in Europe.
What is the risk to humans from the influenza virus in seals?
Some influenza viruses can be shared between animals and people. Influenza A viruses especially can mutate, or change, to cross species barriers and may cause severe disease in their new hosts. For this reason, the Centers for Disease Control, the National Wildlife Health Center, National Institute of Health, state agencies, and other organizations, like NOAA, monitor events involving animal influenza viruses very closely.
Has influenza virus ever been detected in seals in the northeastern United States?
Yes, Influenza A viruses have been detected previously. It has been detected during outbreaks in which the virus caused clinical disease and/or mortality events in seals. It has also been detected between outbreaks in apparently healthy individual seals.
Examples of previous seal influenza events over the past 40 years are below with most recent events listed first:
- 2011: H3N8 isolated from harbor seals during the unusual mortality event in Maine, New Hampshire, and Massachusetts.
- 2006: H3N8 isolated from a by-caught harp seal with no clinical disease.
- 1991–1992: Influenza A viruses isolated from seals that died of pneumonia in Cape Cod, MA; H4N6 isolated from the lungs of two seals; H3N3 isolated from the lungs of three seals. These viruses were isolated from seals that died during a mortality event. The H3N3 strain identified here was more closely related to one that infects birds than any other species (see Callan et al. 1995).
- 1982–1983 harbor seal mortality event in the northeastern United States: H4N5
- 1979–1980 harbor seal mortality event in the northeastern United States: H7N7
What is the phocine distemper virus?
The phocine distemper virus is a type of morbillivirus. Morbilliviruses are in the family Paramyxoviridae and specific morbilliviruses cause measles (in people), canine distemper (in dogs, coyotes, wolves, and seals), rinderpest (in cattle), and peste-des-petits-ruminants (goats and sheep).
Five types of morbilliviruses have been detected in marine mammals in the United States: canine distemper virus and phocine distemper virus in seals and sea otters, and in cetaceans, dolphin morbillivirus, pilot whale morbillivirus, and Longman’s beaked whale morbillivirus.
The phocine distemper virus was first recognized in marine mammals in 1988 in Europe where 60 percent of the North Sea harbor seal population and a few hundred gray seals died. Subsequent large-scale mortality events due to phocine distemper have occurred in seals in Europe.
What is the canine distemper virus?
The canine distemper virus is a morbillivirus that can cause disease in dogs, coyotes, wolves, and seals.
It is a common virus in dogs and most dogs are vaccinated against this virus. Seals can be infected with canine distemper virus and it has caused mortality in seals in the past. Canine distemper virus is not uncommon in wild carnivores in the United States.
What is the risk to humans from the phocine distemper virus?
The phocine distemper virus is not a zoonotic virus and therefore is not transmissible to humans. To date, there has never been a single reported case of human infection with phocine distemper virus. It is unknown if the phocine distemper virus can be transmitted to your dog, so it is best to prevent contact between your dog and seals.
More information on diseases is available from the Centers for Disease Control.
Has phocine distemper virus ever been detected in seals in the northeastern U.S. before?
Yes, the first cases of phocine distemper mortalities documented in harbor seals in the United States was in 1992 on Long Island. Since that time, the phocine distemper virus has been detected at low levels in seals along the northeastern U.S. coast.
The phocine distemper virus played a role in the mortality that occurred in the northeastern United States during the 2006 seal unusual mortality event involving harbor seals, harp seals, hooded seals, and gray seals.
How do the influenza and phocine distemper viruses spread among seals?
Influenza and phocine distemper viruses are usually spread through inhalation of respiratory particles or direct contact between animals, including between mothers and pups. Animals can also be exposed to the virus through other entryways, such as the eyes, mouth, stomach, skin wounds, and the urogenital tract.
How do influenza and phocine distemper viruses affect seals?
The most common organs affected are the lungs (influenza and phocine distemper) and brain (phocine distemper). Sick animals may appear thin, have respiratory difficulties due to pneumonia, such as sneezing, coughing, teary eyes, and/or exhibit abnormal behavior.
When exposed to influenza or phocine distemper viruses, some animals mount an antibody response and fight the infection. This usually protects against future infections and may reduce severity of clinical disease.
Is there anything you can do to protect the seals from these viruses?
One of the challenges of wildlife management is managing large, healthy populations. Harbor seals in this region are one such group of wildlife. As is the case in many deer populations, diseases can spread quickly within large, dense populations.
We will be instituting testing and management within our rehabilitation facilities to reduce the potential spread of the disease in rehabilitation centers and to reduce exposure for employees and their pets. The public can also help by keeping themselves and pets far away from seals in the wild.
What should I do to protect myself and my pets against these viruses?
You should never approach or allow a pet to approach a live or dead marine mammal.
Seals, like other marine mammals (dolphins, whales, and sea lions), are protected under the Marine Mammal Protection Act. It is important that people and their pets maintain a safe distance from these animals so as not to disturb the animal, which may be just resting on the beach, and to avoid injury to themselves, their pets or the seals. While seals look cute, they are wild animals and can transmit disease. Some safe viewing tips:
- Stay at least 100 yards away from seals or other marine mammals.
- Keep dogs on a leash and don’t allow them to approach seals. Seals and dogs can easily infect each other with diseases since they are closely related species.
- Report sick, injured, or dead seals to proper authorities by
- Calling NOAA Fisheries’ stranding hotline at 1 (866) 755-NOAA (6622).
- Contacting your local marine mammal stranding network member (contact information available on our Stranding Network web page).
The only exception is under strict safety precautions when dealing with a carcass on your private property (see below).
What should I do if there is a dead seal on my property?
Report dead seals by either calling NOAA Fisheries' stranding hotline at 1 (866) 755-NOAA (6622) or contacting your local marine mammal stranding network member. Network members may respond and collect the carcass, or they may instruct you to notify your local municipality (county, city, or town government) for animal control and removal services. In the event that no governmental assistance is available, please reference this guidance from NOAA Fisheries on carcass disposal under the Marine Mammal Protection Act (PDF, 1 page), and operate in accordance with the guidance on the safe handling and disposal procedures for seals developed by the state of Maine.
Does eating seafood pose a risk?
Influenza virus and/or phocine distemper virus do not cause disease in fish so there is no risk of catching this virus by eating fish.
How many seal UMEs have previously occurred along the Northeast coast?
Four previous UMEs involving harbor and/or gray seals have occurred along the Northeast coast in 1991–1992, 2003, 2006–2007 and 2011–2012.
The 1991–1992 UME was localized in Massachusetts, involved approximately 24 harbor seals and the cause of this event was suspect avian influenza virus.
The 2003 UME was localized in Maine and involved an estimated 42 harbor seals and the cause was undetermined.
The 2006–2007 UME extended from Maine to Virginia, involved approximately 1,500 seals including harbor and gray seals, and the cause of that event was the phocine distemper virus.
The 2011–2012 UME extended from Maine to Massachusetts, involved an estimated 784 seals including harbor and gray seals, and the cause of that event was avian influenza.
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.
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.