Indonesia's tin miners target the sea, angering fishermen

Dotted off the coast of Indonesia's Bangka island are scores of crudely built wooden pontoons.

They are equipped to dredge the seabed for deposits of tin ore.

Indonesia is the world's biggest exporter of tin.

The metal is all around you - from food packaging to electronics, and now green technologies.

But that same demand has put miners on a collision course with local fishermen.

As tin reserves have dwindled on land, miners like Hendra have started encroaching on prime fishing territory.

"It's getting harder to mine tin on land so I have to mine at the sea. (There are) no more tin resources left on the land."

Hendra shifted to working in offshore mining a year ago and now operates six pontoons.

He is among scores of so-called artisanal miners who partner with PT Timah.

The state mining company pays about $5 for every kilo of tin sand the pontoons pump up.

While it's a lucrative business for Hendra, fishermen like Maryono have seen their profits plunge.

"The impact for us (from the mining) is incredible, (you can tell) by the shrinking of our catch. We used to get at least 10 kilograms in a day, now, only two kilograms. And sometimes we come back with nothing because the location has been destroyed by an illegal mining site."

This is why the miners have been pushed out to the ocean.

Deposits in the mining hub of Bangka-Belitung have been so heavily exploited that the island resembles a lunar landscape.

There are vast craters and highly acidic, turquoise lakes.

Indonesian environmental group Walhi says the island is now risky for people to live on.

The group has also been campaigning to stop mining at sea.

Activist Jessix Amundian:

"It's been 20 years that people have been doing illegal mining activity on land or sea. This has caused conflicts in society, especially with the fishermen. Also, more importantly, on the environmental impact, mining sites along the coast have caused damage to mangroves."

In a statement, Timah said it communicates with fishing communities to improve their catch.

It says it has built artificial reefs to help restock the sea in line with regulations.

Authorities have cracked down on the tin industry from time to time, particularly illegal mining.

But for these unlicensed miners on the island of Bangka, the lure of rising tin prices is too good an incentive to pass by.