Death of killer whales raises worry about the survival of the species

Threatened species: An orca in the waters off San Juan Island in the US state of Washington. Ten years after being listed as an endangered species, killer whale numbers are still falling. Photo: TNS

Despite decades of protection, orcas in Puget Sound are still in decline.

He's trailed them and photographed them, mapped their family trees and counted their offspring, coming to identify individuals by their markings, sometimes even ascribing personalities based on behaviour.