Canada and the USA have two species of otter - the North American River Otter (Lontra canadensis) and the Sea Otter (Enhydra lutris).
The North American River Otter occurs in freshwater habitats including rivers, lakes and swamps. It also lives on rocky coastlines in Alaska, California and British Columbia.
Around 50,000 North American River Otters are killed each year by legal trapping throughout the USA and Canada (CITES Trade Database, 2013). It is believed that the North American River Otter population is stable (IUCN Red List) but without proper monitoring of populations and 50,000 trapped annually this is largely unknown. Read more about this on Paul’s Blog.
Sea Otter populations continue to decline worldwide due to a number of factors – pollution, lack of food and disease (IUCN Red List). In 2015, in Alaska, more than 300 Sea Otters died; an alarming number in comparison with previous years. The main cause of this was toxic algae that formed in the Pacific. On a usual year the algae build up dissipates and is gone within two weeks, but due to a warm patch of water – that set temperature records – the algae never left. Shellfish, a staple of the Sea Otters’ diet, consume the algae which eventually find its way into the Sea Otters. This toxic algae causes seizures and eventually death (National Geographic report – 12 August 2016).
In 2004 many Sea Otters were found dead or dying in California. The cause turned out to be a parasite called Sarcocystis neurona, which is found in the faeces of opossums, and is known to cause brain damage.
However, numbers are now rising in California: in 2013 2,939 animals were counted, and by 2016 this number had increased to 3,272, an increase of 333 otters. (US Geological Society Bulletin).
For more information click below:
North American Otter (Lontra canadensis) Conservation status - Low risk
Sea Otter (Enhydra lutris) Conservation status - Endangered
IOSF supported projects (USA)
IOSF supported projects (Canada)
The River Otter Ecology Project
Friends of the Sea Otter
The otter project