Seals and Society

While many seal species use the waters off of New Bedford, harbor seals and gray seals are the most common and have a year-round presence in New England and beyond.

This web page offers images and information from a new exhibit in development for the New Bedford Whaling Museum. Dive in!

The Basics

If you walk a beach in Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York and even south to Virginia, you may well see a seal. The two most common seals are gray and harbor seals.

Gray seals are much larger than harbor seals, and the males and females look quite different. Adult males can weigh up to 800 pounds (females are about half that). Harbor seals, in comparison—both male and female—only weigh about 200 pounds.

gray seal harbor seal illustrations chart

If you look at the seals’ “noses” you’ll see that gray seals have more of a horse face while harbor seals have a slightly upturned nose. It takes a bit of practice, but once you’ve got the knack, it’s quite easy to identify seal species!

Although their ranges overlap in the eastern U.S., gray seals and harbor seals have quite different life cycles. The times of year when they give birth, mate, moult (replace their coats), and travel for foraging are distinct. Read on to learn more.

 

Seals at Sea


Caption: Harbor seal swimming. Photo credit: Steve De Neef

Seals, like whales and other marine mammals, benefited from the 1972 Marine Mammal Protection Act which protected them from hunting and harassment. In the 19th and 20th centuries, there were literally bounties on the heads of seals. People in Massachusetts, New Hampshire, and Maine could turn in a seal nose and receive a payment from the state. That, however, was stopped in the 1960s when gray seals were protected in Massachusetts and in 1972, when we passed the Marine Mammal Protection Act. Today, seals are resuming their role in the ecosystem. The story of their recovery is still unfolding.

Gulf of Maine map Gray and harbor seals have always lived in the Gulf of Maine and throughout the Northwest Atlantic. Archaeology tells us that seals have been important to people of this region for over 4,000 years. 

By looking at “middens,” the places where people deposited their household waste, researchers have been able to see that coastal communities have always used seals. The details of that story are still being discovered today.

Harbor seals live across the northern hemisphere, in both the Pacific and Atlantic. Gray seals, however, are only found in the North Atlantic. There are three populations of gray seals that are genetically distinct: coastal North America; Iceland, the United Kingdom, Scandinavia, and northern Europe; and in the Baltic Sea.

 

 

Long-Range Swimmers

Gray and harbor seals can easily swim distances of several hundred miles—they can even sleep at sea. When we think about where seals “belong” we need to take a seal’s eye view.

Gray and harbor seals are both “phocids.” The three basic types of pinnipeds (seals, sea lions, and walruses) are the “phocids,” “otariids” and “odobenids.” The “phocids” have no external ear flap and swim by propelling themselves with their webbed hind flippers. The “otariids” have external ear flaps, like sea lions and fur seals, and swim with their front flippers. Walrus are the only living species of odobenid and are known for their prominent tusks.

Researchers have been curious to discover just how far a “normal” seal swims. While we do not yet have information from many seals, the animals that we’ve been able to put satellite tags on have taught us quite a bit.

Harbor-gray seal tracklines

Caption: The left image shows approximately 6 months of movements of two gray seal pups tagged on Muskeget Island, MA in January 2019. The image on the right shows the movements of 3 harbor seals tagged in 2018. Pink and yellow lines show 4-6 months of movement of adult seals tagged in Virginia by the US Navy. The blue line represents a harbor seal pup rehabilitated and released in Long Island Sound.

 

What do they eat?

Gray seal eating
Caption: Gray seal foraging off Cape Cod

This is a question researchers and fishermen alike are curious to investigate.

Research shows that harbor and gray seals eat whatever is abundant locally, which changes with the season and their location. Sandlance, hake, haddock, squid, and flatfish are all part of their varied diet. 

 

How do they find food?

harbor seal with vibrissae alert
Caption: Harbor seal with vibrissae alert.

It’s all in the whiskers. Seals have some of the most advanced sensory systems we know of.

Harbor seals’ whiskers (vibrissae) are so sensitive they can track prey under water from hundreds of feet away, even in the dark, by feeling currents and ripples created by swimming fish.

Seals have good vision, too, but often they are foraging in dark/murky waters. The importance of their whiskers can’t be underestimated!

 

Do they eat too many fish? What role do they play in our ecosystems?

Gray seal peers into a fishing weir
Caption: A Gray seal peers into a fishing weir.
Photo Credit: O. Nichols.

Seals play important ecological roles in our oceans. They provide nutrients both through their poop, which brings nitrogen to areas that need it, and as food for sharks and other predators.

Seals even eat predatory fish that, in turn, eat commercial fish species. Seals are sometimes blamed for declines in fisheries, but the full story is much more complicated. There are many researchers working on finding a way to tell the full story today.

 

Seals Ashore

arial view of group seals on beach
Caption: Aerial photograph of resting seals CCS, NOAA Permit 17670, LOC # 14903

Seals regularly “haul out”—come ashore to rest—sometimes in large groups and sometimes alone. This is normal and necessary. Watching seals at rest on the beach is a wonderful experience.

Gray seals, in particular, like to rest together in large numbers on shore. In summer, they have specific places where they like to gather at low tide. We call these “seasonal haul outs.” These locations are quite stable from year to year, and observing a haul-out of gray seals can be an amazing experience.

Imagine 400 or more gray seals resting close to one another, howling and moaning, wrestling and complaining. It is a sight as dramatic as any watering hole in the African savannah.

Seals will also come ashore to rest individually. Gray seal pups, in particular, can be quite comical. After they are weaned by their mothers at around 3 weeks, they lounge on shore, gaining strength and growing into their adult coat. That time ashore as a pup is critical to gray seals, because once they head out to sea, no one will help them or teach them to hunt for food. They must do it all on their own.

three images seals on rocks in kayak on beach
Caption: (left) Female gray seals on a haul out in Maine. (middle) Harbor seal resting on a kayak in Provincetown. (right) Gray seal “whitecoat” pup at Monomoy Island, Massachusetts in January.

 

seal annual cycle chart

 

Be a good seal watcher!

people on shore observing seals on a sandbar
Caption: Seal watchers at the Cape Cod National Seashore.

If you see a seal on the beach, give them room to rest. Seals come ashore regularly, and it’s not unusual. But they need their quiet time!

For your safety and that of the seals, stay at least 150 feet (50 m) away, and do not touch or feed them. Keep pets on a leash.

For more seal watching guidelines, visit NOAA’s “Share the Shore” website.

100 feet school buss graphic

 

 

 

Seals and Entanglement

gray seal entanglement
Caption: Gray seal with a plastic flying ring around its neck.

Seals are curious, and our oceans contain a lot of human-made materials—from lost toys to fishing gear—that can entangle them and cause severe harm.  

If you see an injured seal, there are people trained to respond and help.

On the East Coast, call the NOAA hotline: 1-866-755-6622.

 


Dive Deeper

If you’d like to read more, there are many resources:

 


This page was created by Ren Bettencourt, Elizabeth Bradfield, and Dr. Andrea Bogomolni as part of their “Seals and Society” education project, which is currently in development.

Generous contributions of data and images have been provided by Steve De Neef, the Atlantic Marine Conservation Society, Center for Coastal Studies, Northeast Fisheries Science Center, Shoals Marine Lab, the Naval Undersea Warfare Center (M. DeAngelis, J. Robinson {Graphics}), and the Northwest Atlantic Seal Research Consortium.

Funding provided by David P. Wheatland Charitable Trust and the Naval Undersea Warfare Center, Newport RI.

Images, unless otherwise noted, were taken under NOAA permits No. 16260, LOC 20412, 775-187, 17670, and LOC 14903.

 


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