Yesterday we talked about the Jackal which as we learned is a member of the canine family.  Today’s animal is known as a “Sea Dog” but don’t let that name confuse you since the Harbor Seal is in no way shape or form related to the jackal or any other canine for that matter.

The harbor seal is known as a “Sea Dog” since they look like earless dogs when they stick their head out of the water.  The thick coats of the harbor seals tend to be greyish colour with black spots or rings.  Even though the harbor seal moults yearly, these markings will remain and are unique to individual seals.  Most of the darker colours will appear on the backs of the seals as with most marine mammals.  This is a defense mechanism so they blend in with the water when looked at from above.  This camouflage will play tricks on the visual predators. Don’t worry, you will still be able to spot them on your ocean cruise while they are sunning themselves on the rocks.

Harbor seals are excellent divers and have something called a dive reflex. This dive reflex is activated the second the seal submerges its head and automatically causes the seal to hold its breath, slow its heartbeat and even reduce the amount of oxygen being delivered to all organs except the brain and the heart.  This dive reflex works so well that the seal is even able to sleep underwater and subconsciously coming to the service for oxygen throughout their slumber.  Imagine how much of the ocean floor you could see if scuba divers had this dive reflex?

I have provided a short video clip that shows the beauty and grace of the harbor seals underwater.  Notice their flippers as they swim.  It is interesting to note that seals are pinnipeds (as are walruses) which is a group of land animals that returned to the sea.  Obviously, this didn’t happen over night but it is still interesting to note some of the unique characteristics that would be reminiscent of a land animal.

Enjoy the video!

Literature Cited:

http://www.northwestwildlife.com/articles/harbour_seal.pdf