The Sea Otter

Characteristics of the Sea Otter

         The Enhydra lutris, more commonly referred to as the sea otter, is the one warm fuzzy coated member of the weasel family who's natural habitat is in the ocean. Sharing the sea with over 15 mammal species , the sea otter possesses the smallest body size of all marine mammals. In relation to all other marine mammals, the small figure of a sea otter would pose as a threat to their species, if it wasn't for their undesirable tasted scent glands. The otter can range in size from 48 to 59 inches, weighing up to 100 pounds, and with a life expectancy of 15 to 20 years. It is said that sea otters have 150,000 hairs per square centimeter in comparison to humans who have a total of 100,000 hair on the entire head. The densely populated fur coat on a sea otter sustains their body temperature in waters as cold as 30 degrees fahrenheit. Whales, seals, and other marine mammals store their heat through their thick layers of blubber. Due to their absents of blubber, the fluffy aquatic otter is a rare species that solely relies on its warm pelt coat to escape from the cold waters. 

         

Ecology 

         As a keystone species, the sea otter plays an important role in its ecosystem. The otters feed off of marine invertebrates such as clams, mussels, abalone, mollusks, crustaceans, snails, and most importantly, they are known for their excessive intake of sea urchins. If however, there becomes too high of a  volume of sea urchins, the lower stems of kelp will be grazed by the urchins, until the kelp dies off and drifts away. It is crucial to have blooming populations of kelp forests in their natural ecosystems. The kelp forests serve as a natural habitat for many marine animals, providing secure feeding and mating grounds for numerous species. In return for the assurance of kelp forests, The otters utilize the kelp as shelter to elude the sea’s predation, resulting in a symbiotic relationship between the otter and the kelp. Depending on the geographical location, the sea otter can encounter great white sharks, seals, and killer whales, which all potentially pose as predators to the sea otter. The great white shark poses the greatest threat, being responsible for 10% of all sea otter deaths. 

         

History

        Historically, the sea otter existed along the North Pacific Rim, spreading from Japan, down to Mexico. In 1670, there were several subpopulations along the pacific coast, making a total estimate of 150,000 sea otters. The otters continued to thrive through out the pacific ocean until the late 1700s, when Russian explorers ventured to North America, with a commercial incentive to hunt for sea otter skins. Prior to the fur trade, the southern sea otter in California had a population of 16,000. At the end of the fur trade in 1911, the sea otters faced a detrimental loss, leaving their species with only 2,000 sea otters in the world. Once the era of overexploitation for sea otters had come to a finish, the species managed to repopulate to 125,831 individuals by 2012. Today, the California sub species is left with a population of 2,941, ranging from san francisco to Santa Barbara. 

Listing

         The southern sea otter (Enhydra lutris nereis) has been listed as threatened since 1973, under The Endangered Species Act. The species has been assessed and red listed as endangered in 2000, 2008, and for the third time in 2013. The entire sea otter species is believed to have lost 50% of its size in the last 45 years. 

         Main Threats

         Today the majority of sea otter mortalities are caused by oil spills, shark attacks, and infectious diseases called Toxoplasma Gondii and Sacrocystis Neurons. In recent years, there has been two main factors contributing to low fitness for the sea otter population. necropsies have indicated that cargo ships and off shore drilling have taken an immense toll on the southern sea otter population. The oil can soak into the fur, drying out natural fur oils that are needed to retain the sea otters body temperature. The sea otters will then die from hypothermia. The harmful chemical will also cause severe liver and kidney damage.

        Recovery Plan 

         It is crucial to reduce evident factors pertaining to loss of sea otter population. The recovery plan claims that managing petroleum exploration, extraction, and tinkering will be the determining factors to weather or not sea otters will become delisted. The plan also states that reducing fishery in the ocean will have a positive correlation with sea otter by catch and boat strikes. 

         Cutting down on your consumption of oil based products will reduce oil activity in our oceans. Below is a list of personal actions that will support the sea otter population. 

• While running short errands, use a bike or walk. Try to avoid forms of transportation that run on oil.
• Try networking a public carpool for your daily commutes. 
• Reuse containers as often as you can.
• Bring reusable bags or paper bags to use when shopping. Stay away from all plastic bags.

Click on this link, (http://www.seaotterfoundationtrust.org) if you would like to contribute to a foundation supporting sea otter conservation. 

By: Andres Aceves

citations: 

Doroff, A. & Burdin, A. 2015. Enhydra lutris. The IUCN Red List of Threatened Species 2015: e.T7750A21939518. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T7750A21939518.en. (Accessed December 1, 2015).

Wharton Media. “Sea Otters.” Seaotters web site:

http://seaotters.com/sea-otters/ ( Accessed December 2, 2015).

U.S. Fish and Wildlife Service. “Southern Sea Otter.” U.S. Fish and Wildlife Service web site: https://www.fws.gov/ventura/endangered/species/info/sso.html (Accessed December 3, 2015).