Tag Archives: Pinnipeds

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

(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 seals 2

(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!harbor seals 1(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






Seal vs. Sea Lion

When discussing the difference between the seal vs. sea lion we can find five main differences that have to do with their anatomy and character traits. The first difference between the seals and sea lions that we will discuss is the shape of their bodies and front fore flippers. The California Sea Lion as pictured in the video have two large fore flippers that they use to help walk on land as well as swim in the water. They are typically slimmer and do not have as much fat as the seal as well. While the Elephant Seal, as pictured and other common seals such as the Harbor Seal, have much smaller fore flippers only used to help swim. They do not use their flippers to walk on land rather “wiggle” their large bodies to help them move. The next notable difference between seals and sea lion has to do with their face and snouts. Sea lions have a large pointed snout, giving the sea lion the look of a slimmer face. While the seal has a compacted snout, giving it a larger and rounder head and face. To finish up the anatomical difference between the two we look at their ears. Sea Lions have large “floppy” external ears while seals have internal ears. Moving on to the traits and habits of seals and sea lions we typically see two main differences. The first is how these two move in the water and surface for air. Sea lions do something called porpoising! Porpoising is when these sea lions will jump completely out of the water in similar fashion to that of dolphins. On the other hand seals will swim completely submerged under water and will come up to take a breath every 5 or so minutes. When they do they will only stick out their head and observe their surroundings. This act is called periscoping. And the final difference between seals and sea lions is the sound that they emit. Sea lions will “bark” like that of dogs while seals will emit a “snarl”. These conclude the five main differences between seals and sea lions. While there are other differences between the two, these are the most notable and talked about differences.

Here on Catalina Island we often see juvenile pinnipeds (seal and sea lions) wash ashore on our beaches. One pinniped in particular is the Northern Elephant Seal. These seals are typically pups that are being weaned from their mothers. When the pups are born they are around 4ft long and weigh about 75lbs (pounds). They will suckle for about 28 days and gain an average of 10lbs (pounds) a day! These elephant seals have some of the richest milk of any pinnipeds in the world averaging about 50% of the milk being actual fat. These elephant seal pups will quadruple in weight from the original 75lbs to an astonishing 250 to 350lbs!! At the end of the suckling period the mother elephant seals will abandon their pups to return to feed leaving these pups to fend for themselves and come ashore. As these pups come ashore to various different locations they will lose some of their weight gained from their mothers and learn how to fend and feed for themselves. We also see juvenile sea lion pups come ashore as well. These pups are usually moved out of their rookery leaving them to feed and fend for themselves as well. If you every see a seal or sea lion pup washed ashore it is best to let them rest and not interfere. These are crucial stages for these animals and any help given to them could cripple their growth and ability to feed for themselves.


We would like to thank you for visiting our blog. Catalina Island Marine Institute is a hands-on marine science program with an emphasis on ocean exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and ocean happenings. This blog has been created by our staff who have at least a Bachelors Degree usually in marine science or related subjects. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science and ocean information. Feel free to leave comments, questions, or share our blog with others. Please visit www.cimi.org for additional information. Happy Reading!