I belong to two organizations that try to help otters:The International Otter Survival Fund is an organization based on the Isle of Skye, Scotland. Otters can be found among the islands of Scotland, and IOSF works for the conservation of these as well as otters all around the world. IOSF also has a rehabilitation center on the Isle of Skye where they care for injured or orphaned otters.
Friends of the Sea Otter is a group based in Monterey, California, who fight to protect the southern sea otter, as well as sea otters in Alaska. Californian otters sometimes get help from the Montery Bay Aquarium, too. This aquarium houses sea otters and sponsors a research and conservation program that includes otter rehabilitation. Orphaned otter pups receive constant care and are returned to the wild when ready.
A great resource for otter fans is Otternet! Read about the 13 species of otters, from the Asian small-clawed otter to the giant otter!