GREAT BARRIER REEF - ENVIRONMENT
News: UN
panel recommends Great Barrier Reef be put on ‘in danger’ list
What's in the news?
● Australia’s
Great Barrier Reef should be listed as a world heritage site that is “in
danger”, a UN panel recommended, saying the world’s biggest coral reef ecosystem was significantly impacted by
climate change and warming of oceans.
Key takeaways:
● Frequent bleaching events
are threatening the reef, including four over the
last seven years and the first during a La Nina phenomenon, which typically
brings cooler temperatures, this year.
● Bleaching
happens when the water warms too much, causing corals to expel the colorful
algae living in their tissues and turn white.
● Australia’s
recently elected Labor government has pledged to spend A$1.2 billion ($800
million) in coming years to protect the reef.
Great Barrier Reef:
● The
Great Barrier Reef is the world’s
largest coral reef system composed of over 2,900 individual reefs and 900
islands.
● It
is stretched for over 2,300 kilometers over an area of approximately 344,400
square kilometers.
● The
reef is located in the Coral Sea, off
the coast of Queensland, Australia.
● It
can be seen from outer space and is the world’s biggest single structure made
by living organisms.
Features:
● This
reef structure is composed of and built by billions of tiny organisms, known as
coral polyps.
● They
are made up of genetically identical organisms called polyps, which are tiny, soft-bodied organisms. At their
base is a hard, protective limestone skeleton called a calicle, which forms the
structure of coral reefs.
● These
polyps have microscopic algae called zooxanthellae
living within their tissues. The corals and algae have a mutualistic (symbiotic) relationship.
UNESCO World Heritage Site:
● It
was listed in 1981 by UNESCO world
heritage as the most extensive and spectacular coral reef ecosystem on the
planet.
Declining Reefs:
● There
was a significant coral bleaching incident on the reef in March 2022.
● The
middle part of the GBR had a 33 percent hard coral cover, compared to 36 per
cent in the northern GBR.
● In
the meantime, the southern region's coral cover levels decreased from 38% in
2021 to 34% in 2022.
● These
corals are more vulnerable to environmental stresses like rising temperatures, cyclones, pollution, and attacks from
crown-of-thorn starfish (COTs), which feed on hard corals, and so on.
● In
the coming decade, global temperatures will rise by 1.5°C, the temperature at
which bleaching occurs more frequently and recovery has less influence.
Resilience:
● Reef
ecosystems are resilient and able to bounce back from disturbances like cyclones,
predatory attacks, compounded heat stress, and more, as long as they don't
happen frequently.