Cyclone affects Barrier Reef
Hammered by a monster cyclone just weeks after flooding spewed toxic
waste into its pristine waters, Australia’s Great Barrier Reef could
face a slow recovery due to climate change, experts warn.
A bleached section of Australia’s Great Barrier Reef. AFP |
Severe Tropical Cyclone Yasi, a top-category storm, ripped through
Australia’s northeast tourist coast Thursday, levelling houses and
decimating crops as it hit land near the city of Cairns, gateway to the
Reef.
Though it is too early to assess the extent of the damage, marine
experts said the sprawling coral structure was bound to have been harmed
by Yasi’s blistering 290 kilometre (180 mile) per hour winds.
“Cyclones do damage reefs,” Nick Graham, a senior research fellow at
James Cook University, told AFP.
“They tend to be be particularly damaging in shallow waters, so they
can break corals and kill areas of live coral, so you get a reduction of
coral cover.... And that then can have a knock-on effect,” Graham said.
The world’s largest living organism, which stretches for 345,000
square kilometres (133,000 square miles) off Australia’s northeast
coast, was already suffering after last month’s record flooding washed a
mucky cocktail of debris, sediment, pesticides and other run-off out to
sea.
Storms such as Yasi have the power to reduce reefs to rubble and
wreak severe damage on living corals.
Smashed fragments have already begun washing up on Australian
beaches, according to the Great Barrier Reef Marine Park Authority, who
estimate that recovery could take 10 years.
“Cyclones are regular events and do affect the coral reef ecosystem
dramatically,” said the authority’s chairman Russell Reichelt.
“However, they tend to be localised to a specific area, compared to
other large-scale effects such as mass coral bleaching caused by climate
change.”
Cyclones are a fact of life on the reef — there were 55 between 1969
and 1997 according to a recent study — but warming and acidification of
the ocean linked to climate change have both increased their frequency
and left corals more vulnerable.
“What normally would have recovered in the past in many other places
in the world takes a long time because the reefs are not optimal; they
don’t have a lot of resilience,” said Professor Ove Hoegh-Guldenburg,
Director of Queensland University’s Global Change Institute.
“The second thing that is happening is that as we heat the oceans
through global warming, we are increasing the frequency of mega cyclones
like Yasi.... which potentially, given (the) circumstances, can have
really big impacts on coral reefs, reducing their ability to bounce
back.”
Coral growth has slowed markedly on the reef since 1990 and parts of
it have suffered severe bleaching due to rising sea temperatures and
acidity that kill its plant-like organisms, leaving just the white
limestone skeleton.
Overall, both this and cyclone damage are symptoms of worsening and
dangerous climate change, said John Merson, from the University of New
South Wales.
“I think probably more damage is being done (to the reef) by the
rising temperature in the ocean which is causing the cyclone, as well as
the reef to be damaged,” said Merson.
“The other question is the complete lack of attention being given to
the fact that we have a category five cyclone because we have climate
change, yet we completely ignore this factor in the whole thing.
“The same thing — the heating of the water — is going to increase
coral bleaching which will knock out the reef in the long term anyway.”
AFP |