Climate Change Puts Corals In More Trouble
Coral reefs have been dying slowly over the past few years, with the biggest bleachings occurring just recently. However, it seems that despite what scientists already know about global warming, they did not expect just how much of an impact it has on the aquatic ecosystem.
As noted by San Diego Jewish World, climate change is killing the Great Barrier Reef in Australia. Terry Hughes of the ARC Center of Excellence for Coral Reef Studies said that it is viewed by the people to be the cause of coral bleaching, which has already been experienced by the Australian coral reef for already 20 years.
A study published in Scientific Reports noted that as a result of moderate ocean warming, 40 percent of corals in a remote reef in the South China Sea died. With the help of studies that analyzed the bleaching history from cores of living corals, the researchers also found the event is most severe and massive in the last 40 years.
The Pacific El Niño in June 2015, for instance, showed the open ocean around the Dongsha Atoll reef in the South China Sea to be about two degrees warmer than usual, with the water above the reef said to be even hotter. Without the monsoon winds that moved the water around to maintain temperature, nearly half the corals died within a few weeks.
Popular Science reported that global warming can jeopardize the ecosystems of coral reefs. Increased temperatures expel the symbiotic algae living in their cells. Once corals lose these algae, which photosynthesize and provide energy for them, they become bleached, starved and will eventually die.
While scientists already have some idea on how high the temperature has to be to cause these corals to die in large scales, human practices can either help these ecosystems thrive or be contributing factors to faster bleaching. The Paris Climate Treaty already imposed an aspirational goal that keeps temperatures below 2 degrees Celsius. This emphasized the urgent need to reduce CO2 emissions to slow ocean warming, or reverse it if possible.
Mark Eakin of the National Oceanic and Atmospheric Administration's Coral Reef Watch noted that coral reefs need as much help as they can, as the global bleaching event that has been going on since June 2014 is still ongoing. Moreover, such severity affects more than just the oceans around the world.