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Marine Mammals of New York

Report sightings of marine mammals to DEC's Flipper Files digital survey. If you suspect a marine mammal or sea turtle is sick or injured, please call the New York Stranding Hotline at 631-369-9829 to report the animal.

From harbor seals on the shores of southeastern Long Island in the winter to humpback whales feeding just off of New York City in the summer, marine mammals can be found in New York year-round. Two groups of marine mammals inhabit these waters, cetaceans (whales, dolphins, and porpoises) and pinnipeds (seals).

Learn more about the six large whale species found in New York and the most commonly seen species of dolphins, porpoises, and seals.

humpback whale breaching
Humpback whale breaching

Pinnipeds (seals)

Cetaceans (whales, dolphins & porpoises)

Seals (Pinnipeds)

Seals are found in New York from late fall until late spring, with the highest concentration generally occurring around April. Seals "haul out" - or leave the water to rest on sandy beaches or rocks - to regulate their body temperature, socialize, give birth, and molt. Hauling out in groups also helps seals avoid predators. Up to five species can be seen locally, but harbor, gray, and harp seals are the most common.

harbor seal hauled out on a rock
Harbor seal hauled out on a rock in Sag Harbor, NY
  • Harbor seals are the most abundant and are easily recognizable by their round head and blunt snout. They haul out in rocky areas and on beaches and are known for their resting "banana" position. They eat fish, shellfish, and crustaceans, which are especially important for nursing mothers during the 4 to 6 weeks they are with their pups.
  • Gray seals have a "horse-like" appearance, especially as adults. They sometimes share areas with harbor seals and can dive up to 1,500 feet for one hour. Pups are very vocal to help their mothers find them. Gray seals eat an array of fish, squid, octopus, and crabs.
  • Harp seals are largely an Arctic species, like the hooded and ringed seals that are more rarely seen in New York, they are present here each year in small numbers. They can be seen within the New York City area and farther up the Hudson River. Adults molt each spring while they eat small species of fish like capelin and invertebrates. They are capable of diving up to 1,000 feet for 16 minutes.


Cetaceans are very diverse. Baleen whales filter feed through brush-like plates, taking in a huge mouthful of small animals like krill. They generally live solitarily but occasionally come together in large groups to feed and/or reproduce. Toothed cetaceans live and hunt in groups and use echolocation to target individual prey. Dolphins have a "melon", the round part on the front of their heads, a beak, and cone-shaped teeth and can be seen in the hundreds. Porpoises have a more blunt head, flatter teeth, and smaller body, and are also less social.

Many of the 90 species of whales, dolphins, and porpoises can be found in the New York Bight - some regularly and some very rarely.

Large Whales

Sperm whale (Physeter microcephalus)
Aerial photograph of a sperm whale
Aerial photograph of a sperm whale.
Photo by: Kate Lomac-MacNair

Status in New York: Endangered
Federal Status: Endangered

  • Diet: Mostly squid which they hunt using echolocation
  • Size: Females on average weigh 15 tons and are 40 feet long. Males weigh 45 tons and are 50 feet long.
  • Lifespan: Live up to 60 years.

Sperm whales, known for their deep diving, are found off New York at the continental shelf break and occasionally in the shallow waters near Montauk and Block Island. They are the only toothed large whale and can dive to over 2,000 feet for up to 45 minutes. Sperm whales have the largest brain of any animal to have ever lived and are named for the waxy substance found in their heads (spermaceti) that was used in candles and ointments when whaling was still practiced.

North Atlantic Right Whale (Eubalaena glacialis)
Aerial photograph of a North Atlantic right whale
Aerial photograph of a North Atlantic right whale.
Photo by: Kate Lomac-MacNair

Status in New York: Endangered
Federal Status: Endangered/ Critically Endangered

  • Diet: They eat about 3,500 pounds of copepods per day with baleen plates that are 8 feet long. The distribution of their prey heavily influences their own locations
  • Size: Grow to be 50 feet long and weigh up to 70 tons.
  • Lifespan: Live to around 70 years.

The majority of North Atlantic right whale sightings in New York is within 50 miles of shore. The species was given its name because it was the "right" whale to hunt. Now, it is one of the most critically endangered large whales in the world with an estimated 400 individuals left. The availability of high-quality prey is important for successful breeding since females reach sexual maturity at 10 years old. Individual whales can be identified by the patterns of white marks (callosities) on their head.

The New England Aquarium in Boston, MA has compiled the North Atlantic Right Whale Catalog (leaves DEC's website).

Blue Whale (Balaenoptera musculus)
blue whale
Aerial photograph of a blue whale.
Photo by: Kate Lomac-MacNair

Status in New York: Endangered
Federal Status: Endangered

  • Diet: Eat primarily krill - up to 6 tons per day.
  • Size: Grow to 100 feet, and weigh 165 tons. At birth, 21 feet and 6,000 pounds.
  • Lifespan: Live on average between 80-90 years.

The blue whale is the largest animal to have ever lived on Earth, as well as the largest species of whale that can be found in all the world's oceans. Their tongue weighs as much as an elephant and their aorta is big enough for a man to crawl through. They are generally found along the continental shelf break. It is believed that blue whales are using the waters of the NY Bight primarily as part of their migration routes from summer feeding areas to lower latitude winter breeding grounds.

Fin Whale (Balaenoptera physalus)
Aerial photograph of a finback whale
Aerial photograph of a fin whale.
Photo by: Kate Lomac-MacNair

Status in New York: Endangered
Federal Status: Endangered

  • Diet: Eat up to 4,000 pounds of krill, small schooling fish, and squid per day. Often feed in groups with other species.
  • Size: Grow to 85 feet, and weigh up to 60 tons.
  • Lifespan: Live up to 90 years.

Fin whales, also known as finback whales, are the most abundant species of large whale in New York and most widely distributed. Can be seen close to shore. They're the second largest whale and can sustain speed of 23 miles per hour, called "greyhound of the sea".

Humpback Whale (Megaptera novaeangliae)
Aerial photograph of a humpback whale
Aerial photograph of a humpback whale.
Photo by: Kate Lomac-MacNair

Status in New York: Currently under review
Federal Status: Not at Risk

  • Diet: Feed on menhaden in New York, up to 3,000 pounds per day.
  • Size: Grow up to 60 feet, and weigh 40 tons.
  • Lifespan: Live an average of 80-90 years.

Humpback whales are very commonly seen around New York, close to shore in the summer and fall, but are also seen further offshore. They're known for bubble net feeding and breaching. Individuals identified by patterns on the underside of their flukes. Learn more about the delisting of humpback whale population segments under NOAA's featured stories (leaves DEC website).

Sei Whale (Balaenoptera borealis)
Sei whale photograph from the Aerial survey
Aerial photograph of a sei whale.
Photo by: Kate Lomac-MacNair

Status in New York: Endangered
Federal Status: Endangered

  • Diet: Feed on plankton and small schooling fish, eating 2,000 pounds per day.
  • Size: Grow up to 60 feet and 50 tons.
  • Lifespan: Live on average between 50-70 years.

Sei, pronounced "say", whales are primarily found offshore of New York near the shelf break but are occasionally found in inshore waters. Limited research available for this species.


Bottlenose dolphins, common dolphins, pilot whales, and Risso's dolphins can often be seen off the south shore of Long Island. Sightings of bottlenose dolphins are the most common since they live closer to shore in coastal waters like harbors and bays. The majority of dolphin sightings occur in the warm summer months when the water is productive.

On average these species live at least 40 years and feed on various species of fish and squid. All dolphins use echolocation to hunt for food and live in groups.

  • Bottlenose dolphins are the most well-known and social species, using unique click and whistle signatures to identify individuals in the group.
  • Pilot whales are the second largest species of dolphin, more regularly found at the shelf edge in deep water, and often associate with other species.
  • Risso's dolphins have no teeth in their upper jaw and use suction to feed on squid. They carry scars on their body that increase with age from teeth raking between individuals.


Harbor porpoises are the only porpoise species typically found in New York's marine waters, seen locally in bays, estuaries, and Long Island Sound. On average they're approximately 5 feet in length and weigh around 150 pounds, and they can live up to 24 years feeding on fish like herring and mackeral, squid, and octopus. Harbor porpoises are listed them as a Species of Greatest Conservation Need for the state. There are seven porpoise species worldwide.

Threats to Marine Mammals

Marine mammals face many threats today with wide-spread and significant impacts. Threats like water quality, marine debris, and noise can bear difficult to mitigate because of the high number of sources. All types of vessels, from small recreational watercraft to large cargo vessels, can pose a threat to marine mammals due to the potential for an unintentional vessel strike. Impacts from fisheries, such as entanglement of large whales and by-catch of smaller cetaceans and seals, are also common and can often lead to long-term health impacts or death even if an animal is disentangled. These threats often overlap and result in a cumulative impact, or multiple threats occurring simultaneously with unknown effects on the population's health. As climate change continues to affect the marine environment in multiple and unpredictable ways, variability in the occurrences of marine mammals and their prey requires additional research and monitoring.

Current Unusual Mortality Events (UMEs)

Under the Marine Mammal Protection Act (MMPA), a Unusual Mortality Events (UMEs) is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." As of May 2020, humpback whales, North Atlantic right whales, and minke whales are experiencing UMEs  on the U.S. East Coast.

NOAA is investigating these events and you can learn more by visiting their Active and Closed Unusual Mortality Events webpage (leaves DEC website).