JAKARTA - Indonesia on Saturday (April 1) blew up and sank 81 more fishing boats caught poaching in its waters.

This takes the total number of boats confiscated and destroyed to 317 since October 2014 when President Joko Widodo took office and called for tougher action against poachers.

Among those sunk so far are fishing boats from Vietnam (142), the Philippines (76), Malaysia (49), as well as one from China. Most were caught by a special maritime task force known as Satgas 115.

The sinking on Saturday was held simultaneously at 12 different locations across the country and supervised by the Indonesian military and police.

Maritime Affairs and Fisheries Minister Susi Pudjiastuti, who observed the sinking of the boats from Ambon, called it a victory for Indonesia's war against illegal fishing.

"There was a time when thousands of foreign vessels came freely to steal our fish, but now they will know, Indonesia will overcome this crime", she said in a statement.

Mr Joko had said last year that Indonesia suffers annual losses of more than US$20 billion (S$29.3 billion) from poaching in its territorial vast waters.

After he was elected, he appointed Ms Susi to the Fisheries Ministry and she has been the main driver behind his plan to revive the shipbuilding and fisheries industries in a bid to re-establish Indonesia as a maritime power.

To achieve the goal, Indonesia has been trying to maximise the potential of the sector through, among other things, modernisation of current industry practices, abolishing trans-shipment activities, and going after poachers.

Enforcement efforts have been ramped up in recent years, including the enhancement of its maritime surveillance capabilities.

Last Thursday, Indonesia's Navy launched two new fast patrol boats - a day after its Air Force announced plans to strengthen its aerial reconnaissance and surveillance capabilities by expanding its fleet of spy planes.

Experts have said the increased security in Indonesia's waters against illegal fishing, smuggling and other border incursions, also comes amid tensions in the region fuelled by Beijing's overlapping claims in the South China Sea.

China claims almost all of the sea lane, while Vietnam, the Philippines, Malaysia, Brunei and Taiwan have overlapping claims.

Jakarta is not a party to the disputes but became concerned after Beijing declared in March last year that the waters around the Natunas, which lie within Indonesia's exclusive economic zone, are part of its "traditional fishing grounds".

In what appeared to many as a veiled response to Beijing's claim, Mr Joko in June last year, boarded a warship for a visit to the waters off the Natuna Islands.