Indonesia is among the world's largest tuna-producing countries and contributes more than 10 per cent of the global tuna trade.

Other major exporters are China, Japan, Korea, the Philippines, Taiwan and Spain.

A recent clampdown on illegal, unreported and unregulated fishing by the Indonesian government, which has banned the use of foreign fishing boats and at-sea transshipment, is hurting local fish processing operators.

It has also pushed up the prices of tuna, mainly yellowfin tuna and skipjack tuna. Checks made by The Sunday Times at Ambon's biggest wet market, Pasar Mardika, showed that a tuna weighing 7kg cost 400,000 rupiah (S$42.5), compared to 225,000 rupiah three years ago.

Local fishing firms say the ban has drastically reduced the number of vessels needed to ply their trade in waters off the coasts of Maluku and North Sulawesi. The move has benefited the southern Philippines.

For instance, the haul brought to General Santos City, which has the largest tuna port in the Philippines, rose 24 per cent to 52,299 tonnes in the first half of this year compared to the same period last year, according to the Philippines Fisheries Development Authority.

This is because tuna are migratory fish and underfishing in one country will have a positive effect in another, according to the Asian Development Bank.

One migration route passes through Indonesia - from the western part of Sumatra in the Indian Ocean to the south of Java, and then coming up around Maluku - before reaching the southern Philippines.

Other routes are from the Pacific Ocean, moving along the northern part of Papua before turning north towards the Philippines.

Indonesia has not made the most of its maritime resources but President Joko Widodo has an ambitious programme to change all that.

Besides an ongoing crackdown on illegal fishing, the government plans to build more than 20 seaports and cold storage facilities to support the local fishery sector.

Wahyudi Soeriaatmadja