What is the main cause of mass coral bleaching on the reef?

Too many tourists touching coral

Great Barrier Reef Quiz: Corals, Islands and Turtles of Australia

This Great Barrier Reef quiz dives into the world's largest coral reef system off Queensland, Australia, with questions on its length, what coral polyps are, coral bleaching, the crown-of-thorns starfish, Heart Reef, Whitehaven Beach, Captain Cook's Endeavour, mass coral spawning and the green turtles of Raine Island. Ten questions.

Start Great Barrier Reef Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 90 Seconds

Question 1 / 10 Time: 90s

States
The Great Barrier Reef lies off the coast of which Australian state?
Size
Roughly how long is the Great Barrier Reef?
Corals
Corals are built by tiny creatures called polyps. What are polyps?
Bleaching
What is the main cause of mass coral bleaching on the reef?
Predators
Which spiny creature, during outbreaks, eats huge areas of coral on the reef?
Shapes
Heart Reef, a small coral formation in the Whitsundays, is famous for what?
Beaches
Whitehaven Beach, on Whitsunday Island, is famous for its unusually pure what?
Explorers
In 1770, which explorer's ship, the Endeavour, ran aground on the reef?
Spawning
The reef's famous mass coral spawning usually happens a few nights after what?
Turtles
Raine Island, on the northern reef, is home to the world's largest nesting site for which turtle?

Explanations: answer key for all 10 questions

Q1: The Great Barrier Reef lies off the coast of which Australian state?
Answer: Queensland
Cairns, Port Douglas and the Whitsundays are popular gateways. Western Australia's Ningaloo Reef is another famous reef, on the opposite coast.
Q2: Roughly how long is the Great Barrier Reef?
Answer: About 2,300 kilometers
It is made of about 2,900 individual reefs and 900 islands. The reef is so large that it can be seen from space.
Q3: Corals are built by tiny creatures called polyps. What are polyps?
Answer: Animals
Polyps are related to jellyfish and anemones. They build hard limestone skeletons and get food from algae living inside them.
Q4: What is the main cause of mass coral bleaching on the reef?
Answer: Unusually warm sea water
Heat stress makes corals expel the colorful algae that feed them, leaving them white. If the heat lasts too long, the corals can starve and die.
Q5: Which spiny creature, during outbreaks, eats huge areas of coral on the reef?
Answer: The crown-of-thorns starfish
A single starfish can eat several square meters of coral a year. Divers control outbreaks by injecting the starfish with vinegar or bile salts.
Q6: Heart Reef, a small coral formation in the Whitsundays, is famous for what?
Answer: Its natural heart shape
It is best seen from a seaplane or helicopter. Visitors are not allowed to snorkel on it, to protect the coral.
Q7: Whitehaven Beach, on Whitsunday Island, is famous for its unusually pure what?
Answer: Silica sand
The sand is about 98 percent silica, so it stays cool underfoot even in summer. It is often named one of the best beaches in the world.
Q8: In 1770, which explorer's ship, the Endeavour, ran aground on the reef?
Answer: Captain James Cook
Cook's crew threw cannons overboard to lighten the ship. They repaired it on the riverbank where the town of Cooktown now stands.
Q9: The reef's famous mass coral spawning usually happens a few nights after what?
Answer: A full moon in late spring
Many corals release eggs and sperm at the same time, creating an underwater snowstorm. It usually happens in November or December.
Q10: Raine Island, on the northern reef, is home to the world's largest nesting site for which turtle?
Answer: The green turtle
Tens of thousands of female green turtles can nest there in one season. Six of the world's seven sea turtle species are found on the reef.

Great Barrier Reef Quiz – The World's Largest Reef

The Great Barrier Reef is the largest coral reef system in the world. Stretching about 2,300 kilometers along the coast of Queensland in northeastern Australia, it is made up of around 2,900 individual reefs and 900 islands. It is so big that it can be seen from space, and it has been a UNESCO World Heritage Site since 1981.

The reef is built by billions of tiny animals called coral polyps, which create hard limestone skeletons. Over thousands of years, these skeletons have formed huge reef structures. Corals get much of their food and color from algae that live inside them. Each year, after a full moon in late spring, many corals spawn together in a spectacular event.

The reef supports an amazing range of life: more than 1,500 species of fish, hundreds of types of hard coral, sharks, rays, dolphins, dugongs and six species of sea turtles. Raine Island hosts the world's largest green turtle nesting site, and humpback whales visit in winter.

The reef faces serious threats. Warming seas have caused several mass bleaching events, when stressed corals lose their algae and turn white. Outbreaks of crown-of-thorns starfish, cyclones and pollution add pressure. Scientists, Traditional Owners and park managers work to protect and restore it.

Visitors snorkel, dive, sail and fly over the reef from gateways such as Cairns and the Whitsundays, home to Whitehaven Beach and Heart Reef.

Aboriginal and Torres Strait Islander peoples have connections to the reef going back tens of thousands of years, long before Captain Cook's Endeavour struck it in 1770. More than 70 Traditional Owner groups help care for its sea country today.

This quiz covers the geography, wildlife, history and conservation of the Great Barrier Reef.

What This Quiz Teaches

This quiz is perfect for divers, nature lovers and geography fans.

Where the reef is and how large it is
What coral polyps are
Why coral bleaching happens
Threats such as the crown-of-thorns starfish
Heart Reef, Whitehaven Beach and Captain Cook
Coral spawning and turtle nesting

Quick Facts About the Great Barrier Reef

The reef is protected by the Great Barrier Reef Marine Park.
Some reefs are thousands of years old.
Clownfish, like Nemo, live among sea anemones on the reef.
Lady Elliot Island is known for manta rays.
Dwarf minke whales visit the northern reef each winter.
Box jellyfish appear in coastal waters during the warmer months.