By Peter Hickey | 03 February 2016 06:00:17A lot of people are wondering whether humans are the cause of the Great White Barrier Reef’s demise.
And while that’s certainly a question worth asking, there’s no definitive answer.
There are a few possibilities, says Dr. Peter Hester, a researcher at the University of Queensland and the National Climate Change Centre at ANU.
One of them is that there are a lot of factors involved.
Some of them are quite complex.
The reef has been in decline for decades.
Its health, productivity, and sustainability has been undermined by changes in climate, the coral that grows there, the pollution it’s exposed to, and the effects of pollution on the fish that live there.
Hester says there are some possible explanations, but those have yet to be confirmed.
“The answer to that is probably no,” he says.
“What we’re finding is that over time, things that are associated with CO2 are more likely to cause coral bleaching, and bleaching is linked to increased mortality of coral reefs.”
And there’s a really good case to be made that the more bleached the reef is, the more the ocean will be exposed to CO2.
So the more CO2 in the atmosphere, the greater the risk of bleaching.
“Hester also points out that some of the factors that are linked to bleaching can also be linked to changes in ocean chemistry.
In the Great Ocean, a lot more carbon is in the water than in the air, and when that carbon is released, it causes the water to lose its ability to hold on to water molecules and the water starts to dissolve into the ocean.
Hierse says that means that the CO2 that’s in the ocean isn’t being absorbed by the ocean, but instead, it’s being released in a way that causes it to be released to the atmosphere.”
There’s some evidence that there is a link between changes in carbonate concentration in the environment and coral bleached reefs, so that could also be an explanation,” he explains.
There’s also the fact that coral reefs grow in the tropics and they grow in a variety of different places.
So, when the Great Lakes and the Pacific Ocean cool down, the tropical water gets more acidic, which reduces the amount of carbonate in the sea water.
And if CO2 emissions are linked with increased coral bleach, it could mean that more COII is being released into the oceans.
Hickey says there is still a lot to learn about the cause and effect of coral bleaches.
But it’s clear that some things that happen in the oceans, like acidification, could be linked with a decline in the quality of coral reef.
Hesters believes there’s been a lot that hasn’t been explored in terms of the effects on coral reef, including the potential of CO2 to cause bleaching.
But he says there’s still plenty of time to investigate further.”
What we’ve seen is that it’s a complex system that’s constantly changing,” he tells The Next World.”
We need to understand how it’s changing.
But we need to start studying it now.