Harbor Seals 101

Have you ever noticed a speckled mammal trying to camouflage into rocks along the California coast?! If so you may have spotted a harbor seal! Harbor seals are marine mammals that belong to a group called pinnipeds (meaning “fin-footed”). Harbor seals are found north of the equator along the Atlantic and Pacific Oceans. They range from Alaska all the way down to Mexico, and are commonly found in coastal waters, rocky islands and on sandy beaches.

(Harbor Seals along a coastline.)

Harbor Seals typically have spotted coats in a variety of shades that range from white, dark browns, and even black. They range around 5 to 6 feet in total length and have very small flippers. They move along on land by flopping around on their bellies. They also lack earflaps, and have internal hearing. A fatty tissue known as “blubber” helps to keep them warm. They also have very large eyes that help them to see in dark, deep water.

A baby harbor seal is called a pup. When pups are born they can swim at birth and sometimes when they are tired they will even ride on their mother’s back! Pups are weaned around four weeks old and females will mate and give birth to one pup every year. Harbor Seals can reach a lifespan of up to 30 years!

The harbor seal spends about half of its time on land and the other half in water. They can dive up to 1500 feet and hold their breath for up to 40 minutes! An average dive however is typically shallow and lasts around three to seven minutes. Unlike humans, they breathe out before diving deep into the water. They then use oxygen that is already in their blood and muscles while underwater. Their heartbeat actually slows from around 100 beats per minute to just 10!


(Harbor seal lounging on a sandy beach.)

The diet of a harbor seal consists of flounder, sea bass, cod, squid, and octopus. They actually use their whiskers to help them hunt and navigate by sensing pressure waves from fish and underwater objects! (Left: Harbor seal using its long whiskers to help it hunt for prey.)

All in all, the harbor seal is one charismatic marine mammal. From their cute appearance to their smooth swimming style, these seals have earned their cuddly reputation. Go out to the beach now and try to find one of these marine mammals on a snorkel so you can truly see their beauty!

Written By: Brooke Fox