50 Fun Facts About Great Barrier Reef

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

It sits in the Coral Sea, separated from the mainland by a channel up to 160 km wide.

Roughly how many individual reefs make up the Great Barrier Reef?

It also includes about 900 islands and stretches more than 2,300 km.

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

It was built by billions of tiny coral polyps and can be seen from outer space.

In which year was the Great Barrier Reef selected as a World Heritage Site?

CNN named it one of the Seven Natural Wonders of the World in 1997.

Which explorer was the first European to encounter the Great Barrier Reef, in 1770?

His ship Endeavour ran aground on 11 June 1770 near today's Cooktown and took seven weeks to repair.

Who gave the Great Barrier Reef its name after mapping it in detail in 1802?

He used 'barrier reef' for any reef that kept ocean swell or ships from reaching the coast.

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

The crew lightened the ship and refloated it on the incoming tide.

Which famous ship sank on the reef on 29 August 1791, killing 35 men?

The Queensland Museum has excavated the wreck since 1983; over 1,600 wrecks are known in the reef region.

Aboriginal Australians have lived in the reef region for at least how long?

Torres Strait Islanders arrived about 10,000 years ago; some 70 clan groups hold the reef as a cultural feature.

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.

The current living reef structure is believed to have begun growing roughly how long ago?

It sits on much older limestone platforms; the sea level at that time was about 120 metres lower than today.

Coral reefs need sunlight, so the reef cannot grow below what depth?

Reefs also cannot grow above sea level; they gain 1 to 25 cm in height a year.

Which reef feature, found in the northern Great Barrier Reef, is not found anywhere else in the system?

The system has no atolls at all, and reefs attached to the mainland are rare.

A previously undiscovered reef found in the northern area in 2020 stands how tall?

It is 1.5 km wide at its base, taller than the Empire State Building.

What is a 'wonky hole'?

The nutrient-rich freshwater can cause local eutrophication.

Roughly how many species of fish live on the Great Barrier Reef?

They include the clownfish, red bass, red-throat emperor, snappers and coral trout.

How many species of sea turtle come to the reef to breed?

Green, leatherback, hawksbill, loggerhead, flatback and olive ridley all nest there.

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

Fifteen species of seagrass feed them and the turtles; native title holders may still hunt them for personal use.

How many species of cetacean have been recorded on the Great Barrier Reef?

They include the dwarf minke whale, Indo-Pacific humpback dolphin and humpback whale.

Reefs of the inner Great Barrier Reef mass-spawn during the week after the full moon in which month?

Outer reefs follow in November and December; the event is cued by rising water temperature and the lunar cycle.

How many coral species, hard and soft, inhabit the reef?

Fast-growing Acropora is the dominant type and drove the record recovery reported in 2022.

How many species of sea snake live on the reef?

None is endemic or endangered, and they are more common in the southern section.

Close to how many mollusc species have been recorded on the reef?

They include the giant clam, nudibranchs and cone snails.

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

215 bird species visit, nest or roost, including the white-bellied sea eagle and roseate tern.

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

A 2000 outbreak stripped 66% of live coral on sampled reefs; the animal has up to 21 venomous arms.

Fertiliser runoff helps the coral-eating starfish because a doubling of chlorophyll does what to larval survival?

More phytoplankton means more food for the larvae, which is why farm runoff feeds outbreaks.

What does the Great Barrier Reef Marine Park Authority consider the single greatest threat to the reef?

Warmer seas drive coral bleaching, which struck in 1998, 2002, 2006, 2016, 2017 and 2020.

Coral bleaching happens when stressed corals lose what?

The zooxanthellae give coral its colour and feed it through photosynthesis; without them the coral starves.

A 2020 study found the reef had lost what share of its coral cover since 1995?

A 2012 study had already reported the same for the period since 1985.

Which magazine controversially published an obituary for the Great Barrier Reef in late 2016?

Scientists called it premature and said it undermined efforts to build the reef's resilience.

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

About 80% of the adjoining land is farmed, largely sugar cane and beef cattle.

Sediment from which Papua New Guinea mine threatens the far northern reef and Torres Strait?

The sediment carries high levels of copper and other heavy metals.

The bulk coal carrier that ran aground on Douglas Shoals in April 2010 was called what?

It spilled up to four tonnes of oil and did extensive damage; reef pilots still prefer the inner route as safer.

The state government's shark control program killed roughly how many sharks between 1962 and 2018?

It uses nets and 173 lethal drum lines in the reef; Humane Society International sued to stop it in 2018.

The Great Barrier Reef Marine Park was created by the Australian government in which year?

Royal Commissions had already ruled out oil drilling on the reef.

The 2004 rezoning raised the marine park's highly protected zones from 4.5% to more than what?

It was then the largest marine protected area in the world, until the Northwestern Hawaiian Islands monument in 2006.

Which minister approved the Abbot Point dredge-dumping plan in December 2013?

After the World Heritage Committee objected, the spoil was dumped on land instead and dumping in the marine park was banned.

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

It focused on water quality, restoration and killing starfish; a AUD$443 million grant to the reef foundation in 2018 drew backlash for skipping tender processes.

Tourism on the reef is concentrated in the Whitsundays and which city?

The two areas make up just 7 to 8% of the park but have their own management plans.

A 2013 Deloitte report valued the reef's tourism at roughly how much per year?

Around two million people visit each year and the industry employs more than 64,000 people.

Cook named the Whitsundays for the day he sailed through them, which he believed to be what?

The 74 continental islands lie 900 km north of Brisbane, with Hamilton Island as their commercial centre.

Google launched an underwater 3D Street View of the reef in which year?

It arrived the same year the marine park authority permitted the Abbot Point dredge dumping.

The 2003 Pixar film Finding Nemo opens with a clownfish couple living on the edge of what?

Nemo ends up in a dentist's fish tank in Sydney; the film grossed $871 million.

The 2022 Australian Institute of Marine Science survey showed the reef's greatest recovery in how many years?

Two-thirds of the reef regrew thanks to fast-growing Acropora coral, though bleaching hit again in 2022.

The Great Barrier Reef stretches for roughly how many kilometres?

Its 2,900 reefs and 900 islands cover an area of about 344,400 square kilometres.

Which French navigator encountered the reef in 1768, two years before Cook, but did not explore it?

Cook's Endeavour then ran aground on the reef on 11 June 1770 and was saved by lightening the ship on an incoming tide.

How many ships were recorded lost in the reef region between 1791 and 1850?

Surveys from 1815 to 1860 by ships including HMS Fly and the Rattlesnake charted the perils of the Inner Route.

Which institution has led archaeological digs on the wreck of HMS Pandora since 1983?

During the 19th century some reef islands were mined for guano while lighthouses went up as beacons.

How many species of seahorse have been recorded on the Great Barrier Reef?

Forty-nine species of pipefish and close to 5,000 mollusc species, including the giant clam, share the reef.