Meeting the UNESCO's World Heritage Criteria

The Great Barrier Reef, in many ways, defies description. The biggest structure ever built by living things and the only one visible from outer space; home to one of the world's most complex and uniquely diverse ecosystems; and, a destination, as Sir David Attenborough attests, that is “better than travelling to the moon…”. But what exactly defines the Great Barrier Reef's outstanding universal value as betrothed by UNESCO when it joined the list 35 years ago?

A very big deal: Bigger than 70 million football fields, the Great Barrier Reef is arguably the largest coral reef system that has ever existed and, in 1981, was the first to be inscribed by the United Nations Educational, Scientific and Cultural Organisation (UNESCO) on its World Heritage List, topping all four natural criteria. At the time of inscription, the International Union for the Conservation of Nature noted: “If only one coral reef site in the world were to be chosen for the World Heritage List, the Great Barrier Reef is the site to be chosen.”

Tall order: While it belongs to “all the peoples of the world”, the operational responsibility of safeguarding one of the Goliaths of World Heritage Areas – or, more precisely, 99 per cent of it – rests with the Great Barrier Reef Marine Park Authority (GBRMPA), a Commonwealth government agency established as a statutory authority under the Great Barrier Reef Marine Park Act 1975. The Marine Park stretches more than 2,300 kilometres along Queensland's coast, covering nearly 345,000 square kilometres.  The World Heritage area is slightly larger, spanning 348,000 square kilometres.

That said, the Australian and Queensland governments have an intergovernmental agreement in place that outlines a cooperative approach to protecting the reef's World Heritage values. No small feat, particularly given the fact that UNESCO's “outstanding universal value” tag is bestowed on the basis that a site's disappearance “constitutes a harmful impoverishment of the heritage of all the nations of the world”.

Fantastic four: Spectacular (adjective): Beautiful in a dramatic and eye-catching way. It's a common term adopted by UNESCO when defining exactly how the Great Barrier Reef meets its four natural criteria for outstanding universal value. In summary, the reef ticks all boxes for displaying:

  • Natural beauty and phenomena – UNESCO considers the Great Barrier Reef's “superlative natural beauty above and below the water” provides “some of the most spectacular scenery on earth”, which astronauts agree defies description. The work of billions of tiny organisms known as coral polyps, the reef is not one continuous barrier, but a vast mosaic of some 3000 coral reefs, 600 continental islands, 300 coral cays and about 150 inshore mangrove islands. Many of the cays support “spectacular and globally important colonies of seabirds and marine turtles”, with Raine Island recognised as the world's largest aggregation site for nesting green turtles. The reef's underwater wonderland is home to “spectacular coral assemblages” and a kaleidoscope of fish of every shape and size that rival the full Pantone colour scheme. That's pretty phenomenal.

UNESCO also cites the natural beauty and phenomena of the internationally renowned Cod Hole, near Lizard Island; a magical dive site in the Great Barrier Reef's “Wild North” offering an opportunity to swim alongside 110kg potato cod, as curious and accommodating as labradors. Visitors can similarly observe first-hand other phenomena including nesting turtles and migrating whales, with the opportunity to join swim-with-minke-whale encounters. At the top of list, however, is the Mount Everest of reproduction in nature – the coral spawning phenomenon, first discovered by James Cook University researchers back in the early 1980s, which erupts on the Great Barrier Reef after a full moon in late spring or early summer.  

The world's most famous naturalist, Sir David Attenborough, ranks coral spawning as one of the greatest of all natural spectacles and was fortunate to witness the nocturnal fireworks during filming of his latest three-part documentary.

  • Major stages of Earth's evolutionary history – UNESCO rates the Great Barrier Reef as “a globally outstanding example of an ecosystem that has evolved over millennia”, noting that the area has been exposed and flooded by at least four glacial and interglacial cycles. Today, the Great Barrier Reef includes examples of all stages of reef development from inshore fringing reefs to mid-shelf reefs and shoals, exposed outer reefs and deep water reefs. What's more, climatic conditions over many hundreds of years can be seen in old massive coral cores. Aside from the coral reefs, which comprise just seven per cent of the World Heritage Area, other important features include palaeochannels (past river channels that have filled in over hundreds of thousands of years by sediment); karstic features (landforms shaped by the dissolution of layers of soluble bedrock, such as limestone); submarine canyons and turbidite deposits.
  • Ecological and biological processes – UNESCO notes that “biologically, the unique diversity of the Great Barrier Reef reflects the maturity of an ecosystem that has evolved over millennia”. Globally significant marine fauna groups include a mind-boggling diversity of fish, molluscs, sponges, anemones, marine worms, crustaceans and many others. The reef's 150 inshore mangrove islands also provide important ecological services, while significant human interaction with the natural environment is illustrated by links between Aboriginal and Torres Strait Islanders and their sea-country.
  • Habitats for conservation of biodiversity – as UNESCO puts it: “The enormous size and diversity of the Great Barrier Reef means it is one of the richest and most complex natural ecosystems on Earth, and one of the most significant for biodiversity conservation.” Put simply, no other World Heritage property contains such biodiversity, including:
  • 411 species of hard corals and at least 150 species of soft corals and sea pens;
  • 39 species of mangroves;
  • 15 species of seagrasses;
  • More than 1600 fish species;
  • 136 species of sharks and rays;
  • Six of the world's seven species of marine turtles;
  • More than 30 species of whales and dolphins;
  • 3,000 species of molluscs
  • At least 500 species of worms;
  • About 1,300 species of crustaceans;
  • 630 species of echinoderms (starfish and sea urchins);
  • 14 breeding species of sea snakes;
  • 215 species of birds, including 22 nesting species of sea birds and 32 species of shorebirds;
  • One of the world's most important dugong populations; and
  • 120-year-old giant clams.

Global gong: The Great Barrier Reef Marine Park sets a global benchmark for marine protected area management, with no-take zones covering about 33.5 per cent of the Marine Park or about 115,374 square kilometres. In a big thumbs-up, the World Wildlife Fund earmarked its highest global conservation accolade – a Gift to the Earth award – to the Marine Park's 2004 rezoning, aimed at improving biodiversity conservation.  


Word count: 1115
Author: Shelley Thomas

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