Slow Decline of the Sea Otters

The sea otter population has dropped 12.2 percent since 1997, and dropped in 2001 to 2161 from 2317 in 2000 - a 6.7 percent decline in one year.

The sea otter population has dropped 12.2
percent since 1997, and dropped in 2001
to 2161 from 2317 in 2000 - a 6.7 percent
decline in one year.

Today the sea otter is an endangered species
and a "fully protected mammal" under
California law. They are also protected
under Canadian and Russian laws.

Much of the research on the sea otter has
been done since the 1989 Exxon Valdez oil
spill in Alaska's Prince William Sound.

There are estimated to be a few thousand,
sea otters in Alaska and the Aleutians, a
few dozen in California.

This is down from 300,000 worldwide before
the eighteenth century. In the eighteenth
and nineteenth centuries they were hunted
for their fur. The sea otter lacks the
blubber that keeps whales, seals, and other
marine animals warm, but possesses the
thickest fur of any mammal, up to a million
hairs per square inch.

The sea otter survey encompasses San
Francisco to Santa Barbara. The cause of the
decline is being argued among the scientists;
it could be caused by over-fishing or a
slight rise in water temperature.

A group of scientists believe that the
whale's usual prey, the Stellar sea    
lions and harbor seals, is so diminished that
they're resorting to feeding on otters and
that this is the main reason for the otters'
decline in numbers, but this is debatable.

James Estes of the US Geological Survey
believes that the otters are too fat and
healthy to be suffering from food shortages
and no signs of an epidemic or widespread
contaminant have been found.

Researchers have observed that otter
populations dropped in a whale-accessible
area but did not in a bay that the whales
couldn't reach.

It wouldn't take many whales to devastate the
otter population because it is possible that
a single whale could consume 1,825 otters per
year.

Greg Saunders, U.S. Fish & Wildlike Service
coordinator for the sea otter says "The three
year average of survey results indicates that
the sea otter population is more or less stable.
However, the numbers fall short of our recovery
goals for the species."

Resources:
BioScience Online
Chang, Maria L., Scholastic Science World, Feb 22 99
Cohn, Jeffrey P., March 1998
Estes, James, US Geological Survey, 2001
Hay, Mark E., Ecologist, University of North Carolina, 1998