Electric shock fishing poses risk to Myanmar's dolphins
16 January 2015 Last updated at 02:20 GMT
For centuries a species of dolphin has lived and worked alongside fishermen in Myanmar, a country also known as Burma.
It is known as co-operative fishing - but this special relationship between man and mammal may soon be a thing of the past.
Dolphin numbers along the Irrawaddy River have declined to such an extent that they are now listed as critically endangered, and those that remain are now wary of human contact.
The blame is being put on fishermen, some of whom are using car batteries that kill both fish and dolphins with electric shocks.
The BBC's Myanmar correspondent joined a team out looking for Irrawaddy dolphins and spoke to some of the fishermen about the special relationship.