On 9 December 2014 a cargo ship rammed a tanker in the Bangladeshi Sundarbans. Some 230,000 litres of oil spilled into the world’s largest remaining unbroken stretch of mangroves. The Sundarbans, which means ‘beautiful forest’, straddle the border between India and Bangladesh. Both sides are designated wildlife sanctuaries, home to thousands of forest people and endangered creatures like Bengal tigers, river dolphins and the masked finfoot.

By law, heavy shipping traffic carrying hazardous materials has no place there. Yet in Bangladesh, tankers carrying ‘modified cargo’ – oil, pesticides, fertilizers, insecticides, cement and salt – cleave the channels of this fragile ecosystem every day; each crossing a disaster waiting to happen.