Species at Risk

Steller Sea Lion
In the 1800s, the steller sea lion was largely hunted commercially for its meat and in the 1900s it was killed for its predation on valuable commercial fish.  However, with the introduction of the Marine Mammal Protection Act (MMPA) and Endangered Species Act (ESA) in the 1970’s, the taking of the animal is prohibited.  Currently the Western Distinct Population Segment (DPS) is in decline and listed as ‘endangered,’ with the most significant drop in numbers off of the Aleutian Islands.  Steller sea lions currently face threats from commercial fishing and can be entangled in fishing gear and struck by boats.  They must now compete to survive with dwindling fish resources with fishermen who are increasing their efforts.

Sea Otter
Since the 1980’s, the northern sea otter population of the Aleutian Islands has decreased by over 90 percent.  The population was listed as ‘threatened’ under the Endangered Species Act soon after and has been listed ever since.  The sea otter plays a unique role in maintaining the kelp forest ecosystem for other species. They are considered a “keystone species” because they prevent kelp forests from being overgrazed by sea urchins, therefore having a disproportionate impact on their environment in relation to their size.  After barely overcoming a past of historical hunting for their pelts and near extinction, sea otters continue to face more threats today such as habitat loss, oil spills, and entanglement.  The sea otter differs from other marine mammals in its lack of blubber under its fur.  If the fur becomes coated with oil the sea otter is left extremely vulnerable to the cold and elements and can easily die.

Fisheries
The largest fishing port of the United States, Dutch Harbor, is found in the Aleutian Islands; this port brings in $150 million annually.  Among the 450 species of fish caught in the Aleutian Islands are the halibut, cod, rockfish, yellowfin sole, pollack, sand lance, herring, and salmon.  “Groundfish” comprise the most valuable fisheries of the Aleutians -- “groundfish” are fish that live near the seafloor and are caught mainly by trawling the bottom of the seafloor.  Threats include bottom trawling and bottom contact fishing; however, in 2005, over 30,000 square miles of seafloor around the Aleutian Islands were permanently closed to destructive fishing gears.

Deep Sea Coral
Deep sea coral reefs and the benthic communities they support are disappearing each year due to high bycatch removal from the commercial fishing industry.  It is estimated that over 81 metric tons of coral are removed from Alaska’s seafloor annually, with 90 percent of the bycatch coming from the Aleutian Islands and the Bering Sea.  The Aleutian Islands are host to the most diverse species of cold water coral in the world, with 25 endemic species and subspecies to the area.  The Aleutian Islands provide a unique combination of essential features for deep sea coral to flourish, such as exposed rock substrate and nutrient rich waters.  Deep sea coral play an important role in the benthic ecosystems they are a part of  -- hydrocoral structures provide feeding stations for sedentary and sessile invertebrate species and many juvenile fish will use coral as refuge or rearing.  Groundfish are found on deep sea coral reefs and are caught by bottom-trawling, the use of large nets dragging on the seafloor.  At least 84 percent of fish and crab species (that are of commercial importance in Alaska) were associated with coral and its invertebrates.  

Seabirds
The Aleutian Islands host more than 10 million seabirds each summer.  Birds found here include puffins, auklets, gulls, storm petrels, cormorants, terns, kittiwakes, murres, pigeon guillemots, murrelets, whooper swans, tufted ducks, Siberian ruby-throats, wood sandpipers, far eastern curlews, and black-headed gulls.  Nearly half of the world’s population of emperor geese spends their summer in the Aleutian Islands.  The Aleutian cackling goose is now recovered from an ‘endangered’ status and is now re-colonizing the islands.  Decline in seabird populations have been affiliated with impacts from commercial fisheries on the marine ecosystem and also the introduction of foreign rat species by vessel traffic. Oil spills threaten bird species.