BIO227Fall2015.05: NORTHERN SEA OTTER

SAVE THE NORTHERN SEA OTTER (THREATENED)

Image from the Alaska Department of Fish and Game Website

DATE OF LISTING & CAUSE OF LISTING

The Northern Sea Otter was given a recovery plan in July of 2013 and it was approved in August of 2013 by the Regional Director, Region 7, of the U.S. Fish and Wildlife Service. However, the decline of the sea otter began a long time before this. From the mid 1700s to the early 1900s the sea otters were hunted for their unique fur. Their population declined to almost 1000 individuals by the end of this hunting period.

DESCRIPTION & ECOLOGY

The Northern Sea Otter is a marine mammal that belongs to the weasel family. It is the largest member of the weasel family while also being one of the smallest marine mammals. Unlike most marine mammals, sea otters do not have blubber. Instead of blubber sea otters have a very dense fur. Their hair is so dense every square inch of them has anywhere from 250,000 to a million hairs! The average human head has around 100,000 hairs total.
Sea otters eat a lot of food and are not very picky about what they eat. A small amount of the foods sea otter typically eat include: abalone, clams, crabs, mussels, snails, and urchins. Sea otters have to be pretty open to what they eat due to the fact that they must consume about one-fourth of their body weight every day. For the average American male that would mean consuming around fifty pounds of food every day!

Image from The Alaskan Yogi Website

GEOGRAPHIC & POPULATION CHANGES

Sea Otters typically live in shallow waters near coast lines. Currently the Northern Sea Otter lives on the Alaskan coast. Some are found along British Columbia, Washington and Oregon as well. Before the fur trade occurred sea otters also lived on the coast of Japan, Siberia, and the Aleutian Chain. They also stretched from Alaska to Baja California. Their population has changed drastically over the years. Before the fur trade the population was over a million and after it was down to almost 1000. The current population of the Northern Sea Otter is around 100,000 worldwide.

Image from the NatureServe Explorer

Image from the Alaska Department of Fish and Game Website

CURRENT THREATS TO THE SEA OTTERS EXISTENCE

The main threats to the Northern Sea Otter include oil spills, habitat degradation, and conflict with humans. Oil spills directly cause sea otters to die of hypothermia. The sea otters fur is very dense to compensate for them not having any blubber. When oil gets in this fur it becomes matted and allows for the harsh cold seawater to get to their inner layer of skin eventually causing them to die of hypothermia. Not only does the oil destroy their fur, it also damages their kidney, liver, lungs, and eyes. Habitat degradation is just a serious. Pollution is a major issue for most of the world and directly effects the sea otters. The sea becomes contaminated especially near the coast due to pollution run off. This pollution is toxic to the sea otters and causes several different diseases eventually leading to death. Finally another threat to the sea otters is conflict with humans. This issue was the main reason the sea otters almost went extinct to begin with. Hunting sea otters for the fur was a major issue up until 1911 when the International Fur Seal Treaty was put in place. This treaty was very helpful for the sea otters, but their are still humans today that kill sea otters for their fur. Sea otters also die due to accidental entrapment by fishermen. Sea otters main food is what many fishermen are searching for so they are often caught with the rest of the sea creatures. Many fishermen also see sea otters as a threat to their business so they kill them.

Image from treehugger.com

RECOVERY PLAN

The recovery plan for the Northern Sea Otter has helped them a lot. Sea otters are protected under several acts including the Marine Mammal Protection Act and the Endangered Species Act. The recovery plan lists three main objectives with a goal of delisting the Northern Sea Otter from the endangered species list. The first states that we must "achieve and maintain a self-sustaining population of sea otters in each main unit". Secondly we must "maintain enough sea otters to ensure that they are playing a functional role in their nearshore ecosystem". Finally we must also "mitigate threats sufficiently to ensure persistence of sea otters."

Click here for the full recovery plan.