Habitat: They live between rivers and the seashore and dig the hole there. This animal is nocturnal, and it is resting in the roost, and acts alone fundamentally from the evening to early morning, and food is taken in a river or sea daytime.
Population(before and now): Although there was capture of 1000 or more animal, before, 8-20 animals live now.
Reasons for its decline in population: Water pollution by agricultural chemicals, chemical cleaner, waste water from a factories. It make the food protect quantity drop. Until 1960's there was a lot of hunting.
Efforts to save this animal: People of Susaki city, Kochi are protecting Japanese river otters. People of a Shinjokawa valley protect and breed Japanese river otter and the "group which protects the nature and the otter Shinjokawa" were launched. This animal and many other endangered animals were protected in 2000 by the "The law about endangered animals and plans protection".