A marine conservationist says he expects Indonesia's crackdown on foreign vessels found to be illegally fishing could become an effective detterrent.
Indonesian police in West Papua this week sunk another Vietnamese-flagged fishing vessel caught allegedly poaching in the province's waters.
Indonesia has sunk at least half a dozen such vessels in the past couple of months.
Stuart Campbell of Wildlife Conservation Society says over recent decades, increasing numbers of large vessels weighing over thirty gross tonnes have entered Indonesia's waters from countries in the north.
"Countries including Vietnam, China, Philippines, Thailand and others, they fish Indonesian waters, and they've pretty much done it without any problem over the last ten to twenty years. Only recently, since President Jokowi has been elected, has the President and his Fisheries Minister started to crack down on these fishing boats and made them illegal."
Stuart Campbell says that as technology develops, vessel monitoring will improve too.