Stretching for miles across the horizon, a vast armada of Chinese fishing boats trawl the pristine waters close to the Galapagos Islands. Ostensibly fishing squid, the real target for the 265-strong fleet are sharks to serve the appetite for expensive fin soup, costing up to £350 a bowl, sold in markets across China and Hong Kong. Night and day, the vessels – many the size of a football pitch – ransack the seabed, scooping up not only whale and hammerhead sharks but other species including turtles and birds.