Harbor Seal – Phoca vitulina

How long can seals hold their breath underwater?
The answer varies by species. Harbor seals can sleep underwater for as long as 20 minutes. To stay under this long, they slow their heartbeat way down. They usually only dive for three or four minutes at a time. Some seals in the Arctic (Weddell seals) spend a lot of time under the ice and can hold their breath for an hour, and maybe much longer than that.

How deep do they dive?
Harbor seals can dive up to 90 meters (300 feet), but they usually only go three meters (ten feet) below the surface.

How big do harbor seals get?
Male harbor seals grow up to six feet and 250 pounds. Females are slightly smaller. At birth, harbor seals are approximately thirty inches and 20 pounds.

How much do our seals weigh?
Coco's weight varies, depending on the season. We feed her more in winter so she'll have a thicker fat layer to stay warm. Her weight is usually somewhere around 160 pounds. The little seal is not yet full grown (in 2004), and she weighs just a little over 100 pounds.

Do they all have the same color patterns?
No. Harbor seal coloring ranges from almost all white with spots to almost all black with no spots. Pups have spotted silver coats.

Can seals see color?
Yes, to a limited degree. In addition to rods, they also have cones in their eyes that let them see some color.

Can our seals hear sounds from above the water when they are underwater?
Yes, they can hear sounds from above the surface when they are underwater. Seals have better hearing under water than they do in air.

Can seals hear higher pitched sounds, like dogs?
Yes, seals can hear higher pitched sounds than we can. Humans hear sounds up to 20 kilohertz. Although seals usually make sounds from .1 to 10 kilohertz, some seals make sounds up to 70 kilohertz, and we assume other seals can hear those sounds.

Do the aquarium seals "speak?"
Adult female harbor seals rarely vocalize, except when they have pups. Our seals make a grunting, snorting noise when they are angry. Male harbor seals are a lot noisier than females and sometimes make a prolonged groan.

How old are the seals?
The larger seal (we call her Coco) was born in 1996. The smaller one (we call her LuSeal) was born in 2002.

How long do harbor seals live?
Most seals live 12 to 15 years in the wild. In captivity, harbor seals can live 30 years and more.

Where did Coco and LuSeal come from?
They were stranded on beaches in Maine. Coco was a few days old when she was taken in by the Stranding Network. LuSeal was also quite young; she was fed and released after a few months, but within weeks she stranded again, this time in Cape Cod Bay.

Why can't Coco and LuSeal be released to the wild?
Coco has a chronic ear infection that makes it impossible for her to live in the wild. We don't know why LuSeal was unable to live in the wild, but both times she tried she ended up an a beach, starving. The second time she also had an infected flipper and anemia. Living in the aquarium, Coco and LuSeal get regular medical care and they are healthy now, although still unreleaseable.

What do the seals in the aquarium eat? We feed them herring and capelin.

How much do they eat every day?
We feed them approximately 10 pounds of fish per day – more in winter and less in summer.

What do harbor seals in the wild eat?
They eat a wide range of food, including schooling fish, flatfish, crustaceans, and squid.

Do the aquarium seals ever get live fish to eat?
No. All their fish have been deep frozen and then thawed before feeding. This guards against parasites that could make the seals ill.

Where do the aquarium seals go in the winter?
They stay in the pool all year. The water is flow-through water from the harbor, and it is running continuously so it never freezes over. Harbor seals like cold water – they live in cold water around Woods Hole in the winter.

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