Loss of Great Barrier Reef Coral

Why in News?

Recently, Australian authorities reports that the Great Barrier Reef has experienced its greatest annual loss of live coral across most of its expanse in four decades.

Great Barrier Reef

• It is located in the Coral Sea off the coast of Queensland, Australia.
• It is the world's largest and longest coral reef system.
• This complex ecosystem built over millions of years from the calcium carbonate skeletons of coral polyps and hydrocorals.
• It is a UNESCO World Heritage site and a significant tourist attraction.

• Divisions – They extend 1,500 kilometres along the Queensland state coast, into three similarly-sized regions.
  • Northern, Central and Southern.

Recent findings

• Living coral cover shrunk by almost a third in the south in a year, a quarter in the north and by 14% in the central region.
• It shows that more than 30% were bleached across the Torres Strait and the entire northern Great Barrier Reef.
• Nearly 84% of the world’s coral reef area has been affected because of heat stress, at least 83 countries are impacted.
• Coral bleaching has been intensified by back-to-back record global heat years.
• The report highlighted that coral reefs are especially at risk if global warming exceeds 1.5°C (2.7°F) above pre-industrial levels.
• Warm water (tropical) coral reefs are projected to reach a very high risk of impact at 1.2°C, evidence suggesting that coral-dominated ecosystems will be non-existent at this temperature or higher.
• At this point, coral abundance will be near zero at many locations.

Quick Facts

Reference

The Hindu| Great barrier reef loss