More than 80% of Indian Ocean dolphins may have been killed by commercial fishing, study finds

Dolphin numbers in the Indian Ocean may have dropped by more than 80% in recent decades, with an estimated 4m small cetaceans caught as “by-catch” in commercial tuna fishing nets since 1950, according to a study. As many as 100,000 cetaceans – mainly dolphins – were caught in commercial gill nets as by-catch in 2006, with current annual numbers at about 80,000. Published in the journal Endangered Species Research, the study used the changes in the numbers of dolphins caught in commercial gill nets as a way to calculate changes in the numbers of dolphins in the Indian Ocean. The authors say gill-net fishing in the Indian Ocean is “effectively unmanaged” and potentially the biggest unresolved issue facing cetaceans today.