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Southern Sea Otter
Enhydra lutris nereis

Photo: © Brent Plater

Home >> Species >> Southern Sea Otter

Southern Sea Otter
Enhydra lutris nereis

The Southern or California Sea Otter, Enhydra lutris nereis, is the smallest species of marine mammal in North America. Despite its relatively small size, the Southern Sea Otter is considered a "keystone" species in its ecosystem: the Pacfic Ocean's kelp forest ecosystem. They do this by feeding on sea urchins.  When the numbers of Sea Otters decline, increased sea urchin feeding leads to detachment of kelp, which in turn depletes the food supply for other marine animals.

Unlike other marine mammals that rely on a thick layer of blubber to stay warm in the cold waters of the Pacific, Sea Otters rely on their incredibly thick fur—with more hairs per inch than any other mammal in the world—to survive in the marine environment.

But this unique adaptation to life in the Pacific almost proved to be the species downfall.  Fur traders prized Sea Otter pelts, and in the 1700s nearly clubbed and trapped the Sea Otter into extinction.  There were between 150,000 and 300,000 Sea Otters living between Alaska and Baja California before this great hunt, but by 1900 it was thought that the species was extinct. 

Fortunately a small remnant population was found off the Big Sur coast in the 1930s. The current population of these animals, roughly 3,000 in a recent survey, is drawn entirely from this tiny stock that was missed by the fur traders.  The Southern Sea Otter was protected as a threatened species under the Endangered Species Act in 1977. 

Sea Otters once were found along the entire Pacific coast of North America, including throughout San Francisco Bay. Today the species' range is limited to coastal waters between the Santa Barbara Channel and Half Moon Bay. However, occasionally a rogue male will swim north passing through the GGNRA's waters and even enter San Francisco Bay. Nearly every year a Sea Otter is spotted from Inspiration Point or the Crissy Field Wildlife Protection Area, but the opportunities are quite rare.

Conservation Action Item

Although the hunt for sea otters has ended, many threats still impede sea otter recovery.  Oil spills are a major concern, because once a Sea Otter's fur is soiled it cannot retain heat and the animal will die.  But most Sea Otter mortality today is caused by disease.  One of the most disconcerting diseases has been the parasite Toxoplasma gondii. This microorganism isn’t naturally found in the ocean environment, but it is killing Sea Otters.  Marine biologists have determined that the microorganism is getting into the ocean through cat feces: the  T. gondii life cycle can only reach a stage hearty enough to survive the marine environment in cats, and when the organism is shed in cat feces it can wash away into the marine environment.  This is why all cat litter sold in California must have a label warning people not to flush it down the toilet. 

Help encourage Sea Otter recovery by always landfilling--never flushing--kitty litter. If you don't have a cat, ask a cat owner you know to do the same.

For more information about this Conservation Action Item:

UC Davis Sea Otter Research

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Previous Comments

Posted by: Cheryl Erb | 2008-05-23 10:54:11

A lot of cat litter is flushable, so the mfrs need to take that off their labels. Used cat litter should be recycled -- maybe used in gardens. I'm not sure if it can be added to compost, but someone should look into that.

 

Posted by: Ellie | 2008-06-23 11:01:09

Just thought I would mention this new invention. Another contradiction to the fight of flush or dumb cat litter: http://www.treehugger.com/files/2008/06/catgenie-self-cleaning-toilet.php Take notice of the quote at the bottom of the page: "With regard to Toxoplasmosis, it is almost a non-issue for indoor domestic cats. Additionally, even if a cat does get the parasite and sheds the oocysts (eggs) which is what causes the concern they only do this for 2-10 days 1 time in their entire life. Thus an individual cat passes oocysts into the human environment for only a small fraction of its entire life span....The EPA recommends that the best way to handle pet waste is to flush it...."

 

Posted by: G. Marantz | 2008-06-30 09:19:45

Why would you recommend throwing untreated feces into a landfill? Is a little plastic bag going to protect it? Have you ever been to a landfill? Big, really big machines are moving the trash around and crushing those plastic bags wide open exposing untreated waste to all the birds, rats etc. to feast and carry it away to your local neighborhood. At least flushing it will put it threw a waste treatment procedure that will clean it up and make it safer for ALL living creatures. Find a way to kill the parasite at the treatment level and pass a law forcing all animal waste to be flushed. Your way does not solve the problem but only creates a health risk for everyone. Thanks Gerald M.

 

Posted by: SeaOtterFan | 2008-06-30 09:20:29

Seems like it is just the same as what happens to most dog poop. Don't know anyone who flushes their dog poop. Most cat litter goes into the landfill as well, only a few brands are marketed as flushable. Toxoplasma gondii cannot be eliminated in treatment plants, as far as I am aware, at least when it is in its egg/oocite stage. That is the stage it is able to reach in cat feces, which is why they need to go to the landfill, not the ocean where it will kill sea otters.

 

Posted by: B.L. | 2008-06-30 09:21:29

The argument regarding the landfill being more of a health risk is simply unjustified. Actually, the greatest health risk to otters and other organisms from T. gondii infected feces is most likely runoff coming from places like your backyard. The second commenter was correct in stating that treatment facilities will likely not be able to ensure complete elimination of the oocytes. Although treatment plants are able to sterilize and remove many types of contaminants, they have not been designed do deal with this kind of organism/life stage and the unique problems it presents! There is debate as to whether the disinfection and sterilization procedures used by treatment plants to make our sewage safe would actually have any effect on removing oocytes at all since oocytes are essentially a sort of hardy, transitional phase for T. gondii - meant to survive almost like a seed-pod until conditions (i.e. the host) are \'just right\'. Regardless, you are looking at a very small amount of feces going through a treatment plant - compared to a much larger amount of feces that is guaranteed to be accumulating in your backyard... even if your cat is a mostly indoors - it (and all the other local cats) still uses the outdoors for many of its \'functions\'. This all adds up and when it rains, well, it pours... Please recognize that that legislation and regulation (forcing all to flush) is not a practical nor feasible solution. Addressing urban runoff and taking responsibility for the impact our pets and our lifestyles have on the environment would be more to the point...