"A few months ago, my partner and I went snorkelling off the coast of Indonesia. We dove off tiny deserted islands and swam in the deep with giant manta rays, but what I remember most vividly about that trip was not the stunning coral or dazzling array of colourful, curious fish; it was the sheer amount of garbage in the water."

"Shopping bags, plastic cups, toothpaste tubes, orange peel, all manner of human debris followed the currents; waves and waves of junk pooling in the shallow waters. In these parts of the reef, the water was cloudy and full of so much microscopic debris that it stung the skin. I remember watching a majestic giant turtle swim through the gloom as my head bumped against an old Coke bottle bobbing on the surface of the water."