It was a signal the fight against illegal fishing in the region has been taken to a new level: A group of Vietnamese fishing trawlers in flames and sinking slowly after being blasted with gunfire by the Indonesian navy.
Last Sunday, Indonesia sank two more, both from Papua New Guinea, and the government says it plans to sink more captured vessels.
Jakarta's crackdown, which includes setting up a fish theft eradication force, is a long delayed response to years of illegal fishing in its waters. Around 5,000 vessels - mostly from Thailand, Vietnam, China, Malaysia and the Philippines - fish illegally in Indonesian waters. The Indonesian government says this causes annual losses of more than US$20 billion (S$26 billion).
Globally, competition for dwindling fish stocks is intensifying, and so is the potential for flash points at sea, analysts say.
The global fish catch is smaller today than it was in the 1990s, and various studies show that stocks of major commercial species have plunged. A 2013 paper by University of British
Columbia researchers concluded that about 58 per cent of the world's fish stocks have collapsed or are over-exploited.
Soon after the sinking of the Vietnamese trawlers on Dec 5, off the remote Anambas Islands in the South China Sea, the authorities arrested 22 Chinese ships for fishing illegally, according to reports. None of the Chinese vessels has been sunk yet.
The two trawlers flying Papua New Guinea flags were sunk last Sunday in Ambon Bay in the eastern Maluku islands. Tempo magazine said the vessels had 72 Thai and Cambodian crew members as well as seven Indonesians on board.
Indonesian President Joko Widodo's "shock therapy" has had an immediate effect.
The day after two Thai ships were chased and seized among the Riau islands, less than a week after the Vietnamese trawlers were sunk, Mr Praporn Ekuru, chairman of the Songkhla Fisheries Association in southern Thailand, warned Thai trawlers to avoid Indonesian waters.
But he added: "Fishermen have to survive. We have to admit that there are almost no fish left in Thailand. Sometimes, they have to take the risk."
Ironically, a few days earlier on Nov 29, Thai navy patrol ships had arrested 54 Vietnamese fishermen and seized seven boats found operating illegally off the Thai island of Koh Juang.
Across the region, from China to Vietnam to Pakistan, at any given moment, there are likely to be fishermen from neighbouring countries in jail.
Last Wednesday, India's Tamil Nadu state released 30 Sri Lankan fishermen, a day after Sri Lanka released 66 Indian fishermen arrested by its navy.
More than 800 Indian boats and 348 fishermen are currently in Pakistani custody, while India has 118 Pakistani boats and 136 fishermen in custody.
The reality is that illegal, unreported and unregulated (IUU) fishing is rampant around the world and has had a devastating impact, according to the 2014 world fisheries report of the United Nations' Food and Agricultural Organisation (FAO).
Fishing has become more efficient, with satellite, Global Positioning System and sonar tracking enabling fishing boats to find large stocks of fish. Fishing fleets straddle the globe: Boats from Japan fish as far as Argentina, Korean vessels reach the shores of Patagonia, while the Spanish fish in the Barents Sea off icy northern Scandinavia.
IUU fishing may account for as much as one-fifth of the global catch. Financial losses to countries whose stocks have been plundered reach tens of billions of dollars.
The FAO's 2014 fisheries report shows that global marine fisheries production expanded to a peak of 86.4 million tonnes in 1996, but has since generally declined, albeit with fluctuations. Global recorded production was 82.6 million tonnes in 2011, and 79.7 million tonnes in 2012.
Part of the decline has been compensated for by the rise of aquaculture.
Farmed fish production in 2012 reached 66.6 million tonnes, out of the total global fish catch of 158 million tonnes. China, in particular, has seen significant growth in aquaculture, which has helped meet the increased demand for fish consumption. Aquaculture has, to a significant degree, helped take pressure off wild-capture fisheries.
But as demand continues to rise, "the depletion of fish stocks is ongoing and is not being reversed", said Mr Ian Storey, a senior fellow and specialist in regional maritime security issues at the Institute of Southeast Asian Studies in Singapore.
"There are almost no agreements in place to conserve fish stocks in the region, so fishing boats are going out farther and farther, and into other countries' waters.
"Everyone fishes in other people's waters. Incidents involving fishing boats and patrol vessels or warships could spark a military or diplomatic crisis," he said.
Incidents at sea involving fishing vessels have already triggered tension.
In a 2010 incident near the Senkaku/Diaoyu islands, whose ownership is disputed by China and Japan, a Chinese fishing trawler collided with a Japan Coast Guard vessel. The Chinese captain was arrested and detained. The incident triggered a serious downward spiral in the relationship between the two countries.
In May last year, the Philippine navy opened fire on a Taiwanese fishing vessel, killing one fisherman. Taiwan is a major investor in the Philippines; Manila had to swiftly carry out an inquiry, and it apologised to Taipei.
Coastal Africa is losing hundreds of millions of dollars to illegal fishing. In January this year, Senegal in West Africa detained Russian fishing vessels and fishermen. In 2012, the Republic of Congo banned 69 Chinese fishing boats.
Britain and the Netherlands have seen their fishing industries dwindle over the years, partly because of foreign vessels fishing illegally, Mr Wietse van der Werf, Amsterdam-based founder and international director of The Black Fish, said in a telephone interview.
The Black Fish trains citizen inspectors in a dozen countries to monitor fishing ports. It is also helping the Italian Coast Guard with enforcement.
Indonesia's tactics are a harbinger of things to come, Mr van der Werf said.
"The reality is that illegal fishing is becoming a major food security issue. In future, access to fishing grounds and fishing stocks will be a bigger cause of conflict and confrontation. We are increasingly seeing this around Europe," he said.
There is some debate in Indonesia over the legality of sinking foreign ships under the UN Convention on the Law of the Sea. But there has also long been a lobby for harsh measures against illegal fishing. "This has been an issue for 10 years," executive director Ketut Sarjana Putra of Conservation International Indonesia said in a telephone interview.
"I think every country in the region has the same problem. It is just that in the past, in Indonesia, nobody cared about it. Indonesia has now begun to wake up."
The crackdown is only the start of a broad effort to scale up Indonesia's capacity to curb illegal fishing, allow fish stocks to recover and create well-managed fisheries before it is too late, he said.
Underscoring Jakarta's position, Mr van der Werf said: "The point is, illegal fishing is a crime." And so is overfishing of quotas, he added.
It is not easy to generalise about the complexities of illegal fishing in South-east Asia, experts say. But governments are becoming increasingly aware of the huge economic losses and threat to food security.
The Philippines is set to sharply increase fines for illegal fishing, partly because of pressure from the European Union, and also because, according to government data, 10 out of the country's 13 major fishing grounds are over-exploited, reports say.
Last Wednesday, Australia permanently banned "supertrawlers", or vessels that are more than 130m long, from fishing in its waters after a huge public backlash against them. "Oceans can provide us with a tremendous amount of protein, but only if we manage them respectfully and sustainably. In many cases, we are not doing that," said Washington-based Jackie Savitz, a vice-president of Oceana, an organisation focused on conserving the world's oceans.
"What we have also seen in many cases is allowable catch and quota being allocated above what the science would recommend," she said over the telephone.
"The challenge is to build better enforcement and management of fisheries.
"That way, we can start to bring the fisheries back - so they can feed people, and we don't have to fight about it."
This article was first published on December 28, 2014. Get a copy of The Straits Times or go to straitstimes.com for more stories.