The Great Barrier Reef

The Great Barrier Reef stretches about 2,300 km along the coast of Queensland, Australia, and is made of nearly 3,000 separate reefs and hundreds of islands. It is the largest structure built by living things on Earth. It became a marine park in 1975 and a World Heritage Site in 1981, and holds more than 1,500 species of fish, from tiny gobies to giant groupers and reef sharks.

Fish of the reef

The orange clownfish lives among anemones on the shallow reefs, coral trout and potato groupers hunt along the reef edges, and the humphead wrasse, which can grow over two metres, cruises the outer slopes. Reef manta rays visit cleaning stations at Lady Elliot Island in the south. Herbivores such as parrotfish and surgeonfish graze seaweed and keep the corals clear. Cairns and Townsville are the main gateways for divers and researchers.

Bleaching and protection

Mass bleaching struck the reef in 1998, 2002, 2016, 2017, 2020, 2022 and 2024, driven by marine heatwaves. Cyclones, outbreaks of crown-of-thorns starfish and runoff from farms add to the damage. A zoning plan in 2004 made about a third of the marine park no-take. Scientists from the Australian Institute of Marine Science track coral cover each year, which has swung between losses and partial recovery.

Still to be written: Orange clownfish, Leopard coral grouper, Potato grouper, Humphead wrasse, Reef manta ray, Whitetip reef shark.