Great Barrier Reef

Why in news?

• The Australian government recently pledged 1 billion Australian dollars to protect the Great Barrier Reef, months after it narrowly avoided being placed on the UN's cultural agency's "danger" list due to the threat of climate change.
• Since 2015, global heating has fuelled three mass bleaching events that weakened and killed corals across the entire span of the reef.

About Great Barrier Reef:

• The Great Barrier Reef is a site of remarkable variety and beauty on the north-east coast of Australia (Coral Sea).
• It contains the world’s largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of mollusc.
• It is the world's biggest single structure made by living organisms.
  • This reef structure is composed of and built by billions of tiny organisms, known as coral polyps. It supports a wide diversity of life and was selected as a World Heritage Site.
• It also holds great scientific interest as the habitat of species such as the dugong (‘sea cow’) and the large green turtle, which are threatened with extinction.

What is Coral Bleaching?

• Coral reefs originate from a symbiotic relationship between the coral polyps and algae that live in the polyps. Coral bleaching occurs when the coral polyps expel these algae.
• They occur due to factors such as variations in water temperature, acidity & salinity, extreme low tides, sea level rise, excessive sedimentation, zoonotic diseases, cyanide fishing and pollution.
• When coral bleach occurs, it is not dead. Corals can survive a bleaching event. But as they come under more stress, they are subject to mortality.

PRACTICE QUESTION:

Great Barrier Reef is located in which of the following sea?

(a) Bering Sea
(b) Coral Sea

(c) Tasman Sea

(d) Yellow Sea

Answer