Northern Sea Otter(Enhyre lutris kenyoni)
Monica Mendoza
Description and Ecology:
The Northern Sea
Otter is a mammal that only resides in the North Pacific Ocean. Size tends to
reflect the availability of food resources and varies in different populations.
It has very dense fur which provides sources of insulation and buoyancy. The
otter is adaptable to crush prey and is known for being one of the few species
to use tools to break open hard-shelled prey. Diving is a way for the sea otter
to groom, travel, and forage, and has an average swimming speed of 1 m/s. The
otter is an example of a keystone species since it preys on the sea urchin,
keeping the sea urchin population under control, which prevents kelp from being
overly consumed, and destroying it as a resource of food and habitat for other
species.
Geographic and Population Changes:
The sea otter’s movement patterns are linked to different
habitat characteristics, social organization, and reproductive biology. Otters
can occupy home range territories usually up to 20 km. There were a large
number of the sea otter population in Alaska but were pushed to the brink of
extinction by hunters in the beginning of the 20th century. There
are also large amounts of habitat available for recolonization in the waters of
southeast Alaska, south to central California, and along the Kamchatka
Peninsula in Russia. The sea otter population has increased in general with
exceptions such as a decline due to the Exxon Valdez oil spill in 1989. The
California sea otter has increased throughout the 20th century with
some periods of decline in late 1990s and 2007-2009.
Listing Date and Type:
The Northern Sea Otter was listed on August 9, 2005 as
threatened in the Alaska Region.
Cause of Listing and Main Threats:
Although the sea otter can viewed as a predator it can fall
prey to bald eagles, white sharks, terrestrial carnivores such as brown bears,
coyotes, arctic foxes, and killer whales. Predation, in a few specific
instances, is suspected to be a significant source of mortality that has large
population effects. Infectious diseases, biotoxins such as domoic acid, and
contaminants such as heavy metals and organic pollutants has caused stranding,
mortality and loss of habitat. The sea otter population and future recovery of
the population can also be limited by the abundance of prey resource.
Description of Recovery Plan:
There are five management units to develop this recovery
plan which includes: Western Aleutian Islands MU, Eastern Aleutian Islands MU,
Bristol Bay MU, South Alaska Peinsula MU, and Kodiak, Kamishal, Alaska
Peninsula MU. The recovery goal is to control, reduce, or eliminate threats to
the southwest. The three objectives are to achieve and maintain a self-sustaining
population of sea otters in each MU, maintain enough sea otter to ensure they
are playing a functional role in their nearshore ecosystem, and to mitigate
threats sufficiently to ensure persistence of sea otters. The recovery strategy
is that each MU needs a comprehensive system to monitor the population size and
trends. The sea otter will be considered for delisting when there is an
acceptably low likelihood of it becoming endangered. The recovery program
should ensure that Alaska Native Subsistence harvest, incidental take, and
illegal take doesn’t affect recovery. It should evaluate disease and predation
as a threat to recovery. The first priority is that actions must be taken to
prevent extinction or to prevent the species from declining irreversibly.
Works Cited:
Information
Photos(In order of appearance)
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