Five black-finned sharks were swimming back and forth along the white sand coast of Wayag Island, Raja Ampat, West Papua, a fortnight ago. Their fins cut the water surface. But there is no cause for alarm. These carcharhinus limbatuswere just waiting for the entrails of mackerels thrown by four young men from the wooden quay.

"Theyre just like our pets, said Nikson Daat, a Marine Conservation employee in the Kawe Area.

Every time they hear footstep