The Great Barrier Reef is the largest living structure on Earth, stretching over 2,000 kilometers along the coast of Queensland, Australia. It contains over 2,500 individual reefs and 900 islands, and is home to a tremendous biodiversity of marine life including 400 types of coral, 1,500 fish species, sea turtles, and dugongs. The reef has been evolving over 20 million years, with the current structure forming around 6-8,000 years ago from coral polyps that grew on underwater mountains during periods when sea levels rose. However, the reef is now endangered due to threats such as rising ocean temperatures causing coral bleaching, poor water quality from land runoff, and outbreaks of crown-of-

1. AUSTRALIA’S
GREAT BARRIER REEF
• UNESCO World Heritage Site
• Natural Wonder of the World

2. WHAT IS THE GREAT BARRIER REEF?
• Largest living ecosystem and coral reef on the planet
• 2,000 kms along Queensland coast
• Contains 900 islands and cays and 2,500 coral reefs
• Biodiversity- 400 types of coral, 1,500 fish species, 4,000 kinds of molluscs
• Marine creatures- seabirds, whales, anemones, etc.
• Endangered species- dugong (sea cow) & sea turtles
• Evolving for over 20 million years
• Current reef approximately 6-8,000 years old

3. GREAT BARRIER REEF ENDANGERED SPECIES
Dugong (sea cow) Giant green sea turtle

4. HOW DID THE GREAT BARRIER REEF FORM?
• All coral reefs begin with single organism called polyp which catches on rock or shell
and begins to grow
• Underwater mountains- Great Dividing Range
• 4 glacial and interglacial periods alternately exposed and covered the limestone
mountain tops where coral formed
• Run off and rivers eroded limestone when exposed
• Coral grew when covered by ocean
• Geological variation- off-shore reefs, mid-shelf reefs, exposed outer reefs
• Reef shaped by climate change, sea level change, wind and water erosion

5. FORMATION OF GREAT BARRIER REEF

6. HUMANS & THE GREAT BARRIER REEF
• Original inhabitants Aboriginal and Torres
Strait Islanders have fished and hunted
for 60,00 years
• Europeans first “discovered” the GBR in
the 1500s
• In 1770 James Cook wrecked his ship
Endeavor on reef and scientific study
began
• Further exploration and mapping for naval
and economic use
• 800+ shipwrecks have occurred in the
GBR
• Currently protected but used for tourism,
sailing, and scuba diving

7. THREATS TO THE GREAT BARRIER REEF
• Rising ocean temperatures due to climate change
• Coral bleaching- when algae are released from coral tissue due to stress from warmer
water, they become susceptible to disease and starvation
• Water quality- contaminated run-off from mining, agriculture (fertilizer), and land
development by-products combined with warmer water create algae blooms
• Crown-of-thorns starfish outbreaks- fast-moving starfish that attack and digest coral,
can kill up to 10 sq meters of coral in a year

8. THREATS TO THE GREAT BARRIER REEF
Coral bleaching Crown-of-thorns starfish

9. SOLUTIONS TO SAVE
THE GREAT BARRIER REEF
• Reduce carbon footprint and use of fossil fuels
• Coral bleaching- coral nurseries to grow coral and repopulate damage areas
• Water quality- enforce and update current government polices and regulations
• Crown-of-thorns starfish outbreaks- control program where scuba divers inject them
with salt mix that does not harm surrounding ecosystem

10. PROTECTING THE GREAT BARRIER REEF
Coral nursery Crown-of-thorn starfish control