Battle to stop Africa's waters being ravaged by China's dark fishing fleets

As David Attenborough warns of the damage being wreaked on the oceans by seabed trawling, the role of an army of mystery boats is in the spotlight

- Jon Ungoed-Thomas & James Tapper

The Ghanaian flag that droops from the mast of the Meng Xin 10 is one of the few African things about the fishing boat.

The deckhands are Ghanaian, and officially it is owned by a company in Accra. But the officers are Chinese, all the instruments and telemetry are in Mandarin, and the people who call the shots are based in the northeast-ern Chinese port city of Dalian.

For 10 years the blue-hulled vessel, one of at least 30 that investigators have linked to Dalian Mengxin Ocean Fishery, has meandered along Ghana's coastline, dragging a heavy beam along the ocean floor about 200m below, bottom trawling for squid and cuttlefish.

Bottom trawling has been thrust into the spotlight by the new film Ocean with David Attenborough and its footage of a beam racing along the seabed destroying everything in its path, which has provoked outrage.

Campaigners, including Attenborough, hope the film will spur governments into action when the UN Ocean Conference starts tomorrow, and protect west African seas from the devastation that has already been visited on UK and European waters.

More than 80% of the Adriatic Sea has been scarred by bottom trawling, and areas of the North Sea and Irish Sea are also badly affected, with stocks of some fish plummeting. There is a global network of more than 18,000 Marine Protected Areas designated parts of the ocean where habitats and wildlife are supposed to be prioritised - but bottom trawling is allowed in the majority of the UK's 377. "Bottom trawling is one of the most destructive fishing methods globally," said Miren Gutierrez, research associate at ODI Global, the global affairs thinktank.

"It not only indiscriminately removes target and non-target species but also destroys vital seafloor habitats, undermining the regenerative capacity of marine ecosystems."