The headline conflict is not even part of the South China Sea disputes, where China's makes its ridiculously huge claim, here shown in red but usually delineated with a "nine - dash - line" and where Indonesia has no claims:
WikipediaIndonesia's territory on the island of Borneo—which it shares with Malaysia and Brunei—does not have a seacoast on the SCS,
Instead, this dispute is is being waged among the 17,000 islands that make up Indonesia:
From the Asia Times, May 31, 2019:
Fisheries Minister Susi Pudjiastuti is going toe-to-toe with Chinese and other foreign poachers she claims illegally take 80% of her nation’s catch
The catch has expanded dramatically, the fish are bigger and new canneries have sprung up all around Indonesia, all apparent signs of a hale and hearty fisheries industry.....MUCH MORE
But Fisheries Minister Susi Pudjiastuti continues to fight a constant battle since she banned foreign trawlers from Indonesian waters in arguably one of the most notable achievements of Joko Widodo’s first term as president.
In an interview with Asia Times, Pudjiastuti said she believes up to 80% of the nation’s catch is still exported illegally or offloaded on to foreign, often Chinese-owned, mother ships outside its 200-mile economic exclusion zone (EEZ) – a transshipment practice she wants declared an international crime.
Moreover, she says only a quarter of the estimated 3,000 new 100-200 tonne fishing boats built locally in the past three years have been properly registered; the rest are painted the same color and carry duplicate names to avoid paying taxes.
There is big money involved for the 100 or so Indonesian businessmen involved, of whom about 20 own 4,500 of the 7,600 registered boats above 30 tonnes, according to the minister. Annual profits, she says, range from US$1-2 million for 30-100 tonne vessels, and $2-4 million for those in the 100-200 tonne capacity.
The result: many of the Indonesian businessmen who previously engaged in flawed joint ventures with Chinese, Thai and other large regional fishing companies to plunder their country’s maritime resources are now finding ways to do it independently.
Despite all that, the fisheries sector’s contribution to gross domestic product (GDP) has risen from 7.3% to 7.9% in the past three years, growing by 5.7% per year and making Indonesia into the world’s second-biggest producer of fisheries and aquaculture, according to the 2018 European Union Fish Market Report....