History

Source: wvoutpost.com

In the 1700s sea otters were abundant along the Northern Pacific Rim. Their numbers were slightly reduced due to hunting by Native Americans. In the mid-1700s the Russians started the commercial fur trade of sea otter pelts. This led to an extreme decrease in sea otter numbers due to extensive hunting, causing the species to come close to extinction. Sea Otter pelts were highly prized because they are soft and thick; sea otters have the thickest fur of any animal. The population decreased from between 150,000 and 300,000 individuals in the early 1700s to only 2,000 individuals in 1911. In response to this extreme decrease, the otters were protected under the North Pacific Fur Seal Treaty in 1911 (The Otter Project). The North Pacific Fur Seal Treaty was the first legislation that addressed international wildlife protection. The treaty gave the seal populations time to recover, by prohibiting hunting. The treaty remained active for 30 years and was followed by many other treaties including the Fur Seal Act of 1966. The North Pacific Fur Seal Treaty of 1911 is  historically important because it was the first of its kind and led to many other treaties and efforts to protect wildlife (NOAA). 

Produced by Simone Barker
one of two figures produced by Simone Barker 

Once implemented the North Pacific Fur Seal Treaty led to the recovery of the population. The population was recovered from 11 sub-populations that were far dispersed and isolated. Each sub-population grew, repopulating its area. Due to the isolation of these populations they weren't able to interbreed, resulting each having low genetic diversity (IUNC Red List). In small isolated populations you only have the diversity of the individuals in your community, and the fewer members you have the less diverse your population is. Genetic diversity is extremely important for the survival of a population. It provides the differences that allow some members of the population an adaptive edge; when they are affected by things like invasive species, pathogens, or climate change. The individuals that possess adaptive difference would be able to survive these events allowing the species to continue to exist (Groom, chapter 11). During this recovery the Southern sea otter (which lives along California coast) was protected under the Endangered Species Act starting in 1977, where it was listed as threatened (U.S. Fish and Wildlife Service). Since the 1980s there have been many efforts to help recover sea otter population including management and different governmental protection. Even with these efforts sea otter populations continue to be fairly small, this is in part due to the current threats: oil spills, pathogens, predation and possible other reasons that are currently unknown (IUNC Red List). 

The Sea Otter Range along the Northern Pacific Rim 

Source: www.mysanpedro.org

Sources: 

1. "The Otter Project." The Otter Project. N.p., n.d. Web. 23 Feb. 2013.

 <http://www.otterproject.org/about-sea-otters/natural-history/>.

2. "North Pacific Fur Seal Treaty of 1911." NOAA 200th Top Tens: Historical

Events:.NOAA, 19 July 2012. Web. 23 Feb. 2013.

<http://celebrating200years.noaa.gov/events/fursealtreaty/welcome.html>.

             3. "Enhydra Lutris." (Sea Otter). N.p., n.d. Web. 24 Feb. 2013. 

<http://www.iucnredlist.org/details/7750/0>.

             4. Ventura Fish and Wildlife Office." U.S. Fish and Wildlife Service. N.p., 10 Mar. 2013. Web.            
10 Mar. 2013.<http://www.fws.gov/ventura/species_information/so_sea_otter/>

              5.Groom, Martha J., C. Ronald Carroll, and Gary K. Meffe. "Chapter 11: Conservation

Genetics." Principles of Conservation Biology. Sunderland [Mass.:

Sinauer Associates, 2006. 375-404. Print.