Whale shark, Ningaloo Reef, Western Australia

© Jason Edwards/Getty Image

A diver's big buddy. Whale shark, Ningaloo Reef, Western Australia

Say hello to the largest fish in the world, the whale shark. These gentle giants are not related to whales, despite their impressive size of an average 12 metres in length. Whale sharks are calm creatures that are usually safe for divers to swim alongside. These sharks are filter feeders and consume plankton and small fish by sieving them through their gill plates. There has been a significant decline in their populations, with an estimated 63% decrease in their numbers in the last 75 years. Threats include being hit by boats or tangled in fishing gear and their habitats are being damaged by pollution, coastal development and over-fishing. Advocates work through education and community engagement to help safeguard whale sharks and preserve our oceans.