Gray Seal (2024)

Gray seal pups - Photo credit: NOAA Fisheries

Gray seal pups - Photo credit: NOAA Fisheries

Entanglement

Gray seals can become entangled in fishing gear and other types of marine debris resulting in seals swimming off with the gear attached or becoming anchored. They can become entangled in many different fishing gear types including gillnets, trawls, purse seines, and weirs. Once entangled, seals may drown if they cannot reach the surface to breathe, or they may drag and swim with attached gear for long distances. This can ultimately result in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.

Illegal Take/Killing

Gray seals are easy to view in the wild, but this puts them at higher risk of harassment and in some cases, even intentional human-related injuries and death. Feeding (or trying to feed) them is harmful and illegal. It changes their natural behaviors and makes them less wary of people and vessels. They learn to associate humans with an easy meal and change their natural hunting practices—for example, they take catch bait directly off fishing gear. Sometimes they fall victim to retaliation (such as shooting) by frustrated boaters and fishermen.

They may also be disturbed or harassed by the presence of humans and watercraft. Harassment is illegal and happens when any act of pursuit, torment, or annoyance might injure them or disrupt their behaviors. Remember to share the shore with gray seals for their safety and yours.

Chemical contaminants

Contaminants enter ocean waters from many sources, including oil and gas development, wastewater discharges, urban runoff, and other industrial processes. Once in the environment, these substances move up the food chain and accumulate in predators near the top of the food chain such as gray seals. These contaminants accumulate in gray seals’ blubber stores, threatening their immune and reproductive systems.

Oil spills and energy exploration

Oil spills can harm gray seals. If exposed to oil, a gray seal’s fur can no longer repel water. This makes it difficult for the seal to swim, float, and keep warm. Inhaling or swallowing oil can also damage a seal’s respiratory, digestive, reproductive, and central nervous systems. Oil can also irritate or burn the seal’s skin.

Vessel and Vehicle Interactions

Gray seals are susceptible to water vessel and land vehicle impacts. Inadvertent vessel strikes can injure or kill gray seals. Gray seals are vulnerable to vessel collisions throughout their range, but the risk is much higher in some coastal areas with heavy vessel traffic. Due to gray seal behavior, seals are also vulnerable to vehicles that drive on beaches, which is common in some areas of high gray seal density. Vehicular strikes are often fatal to seals, particularly pup or young seals that haul out high on the beach.

Last updated by NOAA Fisheries on 08/06/2022

Conservation & Management

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Science

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How You Can Help

Gray seals, like all marine mammals in the United States, are protected under the Marine Mammal Protection Act.

Reducing Vessel and Vehicle Interactions

Vessels or vehicles can injure,kill, or disturb gray seals. The most effective way to reduce disturbance is for vessels and vehicles to stay away. In the Greater Atlantic Region, we have issued “Watch for Seals on the Shoreline” guidelines to reduce the disturbance of gray seals.

Learn more about these guidelines

Implementing Oil Spill Response Plans in the Event of a Spill

Gray seals are at risk of harm in the event of an oil spill. To minimize the effect of a potential spill on gray seals, NOAA developed the Marine Mammal Oil Spill Response Guidelines.

Learn more about pinniped and cetacean oil spill response guidelines

Overseeing Marine Mammal Health and Stranding Response

We work with volunteer networks in all coastal states to respond to marine mammal strandings including all pinnipeds. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes attribute strandings to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.

Learn more about the Marine Mammal Health and Stranding Response Program

Marine Mammal Unusual Mortality Events

There is an ongoing Gray Seal Unusual Mortality Event (UME), and the species has experienced unusual mortality events in the past. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.

Get information on active and past UMEs

Get an overview of marine mammal UME

Educating the Public

NOAA Fisheries aims to increase public awareness and support for gray seal conservation through education, outreach, and public participation. We share information with the public about the status of gray seals, as well as our research and efforts to promote their recovery.

Incidental Take

NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of gray seals. The results of this research are used to inform management decisions for this species.

Stock Assessments

Determining the size of gray seal populations helps resource managers determine the success of conservation measures. Our scientists collect population information and present the data in annual stock assessment reports.

Monitoring Population Abundance and Distribution

Scientists observe gray seals to record their numbers and distribution. By comparing numbers collected over multiple years, scientists can look for trends—i.e., whether the population is increasing, decreasing, or remaining stable during a given period.

We use photographs taken from the air to monitor gray seal populations in New England. We monitor the number of gray seal pups born on the following pupping colonies: Muskeget, Monomoy, Nomans Island, and Great Point in Nantucket Sound, as well as Seal, Green, Matinicus Rock, and Wooden Ball Islands off mid-coast Maine. As new colonies are established we add these sites to our monitoring plan. We use the pup counts to estimate the size of the total population.

Movements

Our scientists also track gray seals to study their movements and habitat use. This provides insight on where animals may be foraging, important haul-out or pupping areas, seasonal presence in Canada, relationship to predators like white sharks, and use of areas slated for wind energy or other resource development.

Diet and Foraging Ecology

Our scientists study gray seal diet using a variety of methods to understand what and how much gray seals eat and where they are foraging, in order to better understand the role of seals in the ecosystem. This helps us better understand direct and indirect effects of seals on commercial and recreational fisheries as well as other important components of the marine food web.

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