So at first, no one made the connection between a single otter's bad luck in meeting a killer whale and the shrinking otter population.

Children were asked to design an interpretative poster which highlighted the vulnerability and needs of Britain's threatened otter population.

Since then the otter population, most recently under Federal protection as an endangered marine mammal, has increased to about 1,650.

Finally, the researchers calculated what the likely rate of observed attacks would be if whales were responsible for the 90 percent reduction in the otter population.

European otter populations are now recovering in many parts of Europe.

A thriving otter population was the inspiration for author Gavin Maxwell (1914-69) who lived there.

Oil spills present a localized threat to otter populations, especially in coastal areas.

The rivers support otter populations and a wide variety if fish species including Lampreys.

While still present in a number of north-central countries, giant otter populations are under considerable stress.

The otter population has been restored to a healthy level.