46 Fun Facts About Great Barrier Reef

The Great Barrier Reef lies off the coast of which Australian state?

Queensland: it began as part of New South Wales and split off as a separate colony only in 1859.

The Great Barrier Reef Marine Park covers roughly the same area as which country?

Italy: in 2022 the Darumbal people were formally recognised as protectors of 36,606 square kilometres of it, the reef's largest agreement of its kind.

The reef is described as the world's biggest single structure made by what?

Living organisms: coral polyps built it, and though corals can look like plants, each polyp is an animal.

Which UNESCO list has the reef nearly joined?

World Heritage in Danger: UNESCO recommended it in 2021, but Australia's government lobbied successfully against the listing.

Which wildlife TV presenter died in 2006 after a stingray's barb pierced his chest while filming on the reef?

Steve Irwin: the attack was caught on film, but those who have seen the footage say it should never be shown.

Which navigator, who charted the reef in detail in 1802, called its collection of reefs the 'Barrier Reefs'?

Matthew Flinders: on the same voyage he went on to sail right around mainland Australia, charting its coasts.

Cook's ship that struck the reef in 1770 was named what?

Endeavour: guns, ballast and stores were thrown overboard, the ship was hauled off two tides later, and repairs kept it beached for seven weeks.

Which Royal Navy ship, sent to hunt down the Bounty mutineers, sank on the reef in 1791?

HMS Pandora: it sank the morning after striking the outer reef, and 35 men died, among them four of the mutineers it had captured.

When seas were far lower, what lay where the reef now stands?

A coastal plain: ice-age ice sheets had locked up so much seawater that the land under today's reef lay dry.

The reef's northernmost island, in the Torres Strait, is called what?

Lady Elliot Island, 1,915 km to the south-east, marks the other end.

Until about 25 million years ago, why could coral not grow off north-eastern Australia?

Australia has been drifting north about 7 cm a year, and Queensland only entered tropical waters around 24 million years ago.

Which large sea snail is one of the few natural predators of the reef's coral-eating starfish?

Giant triton: it devours the starfish, spines and all, and the over-collecting of tritons is one suspected cause of the starfish's outbreaks.

Which ancient rainforest, often called the world's oldest, borders the Great Barrier Reef on Australia's north-east coast?

Daintree Rainforest: in 2021 it was handed back to its Aboriginal custodians, the Eastern Kuku Yalanji people, who now manage it with the state government.

A 2009 campaign billed as 'the best job in the world' hired a caretaker for the reef's islands, based on which island?

Hamilton Island: the six-month caretaker role was really a campaign to promote the reef worldwide, and it came with a villa on the island.

In 2020 scientists found a detached reef in the Great Barrier Reef's northern waters; roughly how tall is it?

500 metres: after seafloor mapping revealed it, scientists sent an underwater robot down to explore the new reef.

What is a 'wonky hole'?

The nutrient-rich freshwater can cause local eutrophication.

When the breeding female in a group of reef clownfish is lost, what usually happens?

The largest male becomes female: the biggest non-breeding fish then becomes the new breeding male, and the others each move up a rank.

Which turtle nests on Raine Island in the tens of thousands?

Green turtle: after thousands of females died at the island's small sand cliffs, a rescue project reshaped its nesting beaches.

Which large seagrass-grazing marine mammals live in big populations on the reef?

Dugongs: they are the only marine mammals in Australia that live mainly on plants, and as they graze they leave telltale feeding trails through the seagrass.

Humpback whales that calve on the reef feed in which waters each summer?

Antarctic waters: they go there for krill, the small crustaceans that make up most of their diet.

Mass coral spawning on the Great Barrier Reef is triggered by water temperature and which other natural cue?

The full moon: on the nights after it, whole coral colonies release their eggs and sperm at once, filling the water like a snowstorm.

Which fingernail-sized box jellyfish, found in reef waters, can cause a painful and sometimes deadly syndrome?

Irukandji: in 1961 doctor Jack Barnes caught one and tested its venom on himself, his nine-year-old son and a volunteer lifesaver.

Which reef mollusc hunts by stabbing its prey with a venomous, harpoon-like tooth?

Cone snail: one species' venom gave rise to a painkiller used for severe chronic pain, and scientists are testing compounds from others.

Between 1.4 and 1.7 million of what use the reef's islands to breed?

Birds: they carry the seeds of many island plants, and far-northern Raine Island is considered the reef's most important seabird breeding site.

Which starfish preys on coral polyps and periodically devastates the reef?

Crown-of-thorns: its numbers periodically explode into huge outbreaks, and poor water quality is believed to make those outbreaks worse.

To cull the reef's coral-eating starfish, what do divers do to each one they find?

Inject it: a jab takes seconds, while cutting a starfish up is slow and gets divers spiked.

In 2015 Australia announced a ban on dumping what inside the Great Barrier Reef Marine Park?

Dredge spoil: it is seabed dug out to create or deepen shipping channels, and one port project's spoil was sent to land instead of the park.

Coral bleaching happens when stressed corals lose what?

Their symbiotic algae: the algae give corals their colour and most of their food, so a bleached coral starves unless the algae return.

After the 2016 and 2017 mass bleaching, what plunged by about 89% on the reef?

New coral births: so many breeding adults had died that too few were left to replenish the reef, and the mix of coral types changed.

Which US adventure magazine published an obituary for the Great Barrier Reef in October 2016?

Outside: its writer dated the reef '25 million BC–2016', after that year's bleaching had killed coral on a record scale.

Over 90% of the pollution reaching the reef during floods comes from what?

Farm runoff: about 80% of the land beside the reef is farmed, and grazing lands and sugarcane supply most of the sediment, nutrients and pesticides.

As seawater absorbs more carbon dioxide and turns more acidic, what does it make harder for the reef's corals?

Building their skeletons: acidic water holds fewer carbonate ions, the building blocks corals use, and if the pH falls far enough skeletons can even dissolve.

Investigators found the bulk carrier Shen Neng 1 ran aground on the reef in 2010 mainly because of what?

Officer fatigue: the chief mate failed to change course at the planned point, and in 2016 the ship's owners settled with the government for about $29 million.

In 2018, what happened to many sharks found alive on the reef's drum lines?

They were shot: the same drum lines were also recorded killing endangered hammerhead sharks.

In the 1960s, conservationists fought state government plans to allow what on the Great Barrier Reef?

Mining and oil drilling: Royal Commissions ruled out drilling, and in 1975 the federal government created the Great Barrier Reef Marine Park.

The Abbot Point port expansion that Australia approved in 2013 was planned to export what?

Coal: the plan was for three new coal terminals, and one of them was proposed by India's Adani Group.

The Reef 2050 Plan, agreed in March 2015, was criticised for failing to address which root cause?

Climate change: the plan targeted water quality, restoration and culling starfish, and by 2017 experts said its goals were no longer achievable as the climate warmed.

Most visits to the Great Barrier Reef are concentrated around an island group and which city?

Cairns: the town was founded in 1876 as a port for a newly proclaimed goldfield inland.

Captain Cook named a passage through a reef island group after the Christian feast day he sailed it; which day?

Whit Sunday: he sailed through on Sunday 3 June 1770, and the name later spread from the passage to the whole island group, the Whitsundays.

In Finding Nemo, clownfish Marlin and his son live on the reef inside what kind of animal?

A sea anemone: clownfish shelter among its stinging tentacles, and in return they chase away fish that would eat the anemone.

Despite repeated bleaching, how had coral cover changed across much of the reef by 2022?

Recovered strongly: much of the new growth was Acropora, a coral that can grow quickly.

Which businessman's nickel refinery made unauthorised releases of nitrogen-laden water into the reef's marine park?

Clive Palmer: the releases from his refinery near Townsville came in 2009 and 2011, and emerged in 2014 through freedom-of-information documents.

Which French navigator came close to the reef in 1768, two years before Cook, but turned away after meeting heavy breakers?

Louis de Bougainville: he turned north without ever sighting Australia, and the flowering plant bougainvillea is named after him.

Which young naturalist met his future wife in Sydney while a naval assistant surgeon surveying the reef?

Thomas Henry Huxley: the research he did on the voyage won him election to the Royal Society.

Which reef fish grinds up coral and rock with its teeth and excretes it as sand?

Parrotfish: the sand they excrete helps build sandy beaches.

Among the seahorses found on the Great Barrier Reef, which parent carries the eggs until the young are born?

The male: the female deposits her eggs in his brood pouch, where they hatch before he releases the young.