Upcoming Effects of Climate Change
April 17, 2017
James Cook University in Australia reported that for the second time in 12 months coral bleaching is occurring along the Great Barrier Reef.
Coral bleaching has occurred three other times in the past 20 years. It occurred in 1998, 2002, and 2016. This is the first time that coral bleaching has happened in consecutive years.
“The combined impact of this back-to-back bleaching stretches for 1,500 km (900 miles), leaving only the southern third unscathed,” says Prof. Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies, who undertook the aerial surveys in both 2016 and 2017.
“The bleaching is caused by record-breaking temperatures driven by global warming. This year, 2017, we are seeing mass bleaching, even without the assistance of El Niño conditions,” Hughes continued.
Coral bleaching happens when coral is exposed to higher than normal water temperatures. Heightened sea temperatures cause corals to expel tiny photosynthetic algae called zooxanthellae.
The loss of these colorful algae causes the corals to turn white and bleach. Bleached corals can recover if the temperature drops and zooxanthellae are able to recolonize them. If temperatures do not cool the coral may die.
The University of Technology Sydney’s lead reef researcher, marine biologist David Suggett, said that to properly recover, affected reefs needed to be connected to those left untouched by bleaching.
The Great Barrier Reef supports a diversity of life, including many vulnerable or endangered species, some of which may be native to the reef system.
A recently published study in “Nature” stated that local measures can ultimately do little to protect the reefs from bleaching. Securing a future for coral reefs “ultimately requires urgent and rapid action to reduce global warming.”