Thursday, 1 December 2011

The not so O.K. Coral... reefs.

A large bed of dead coral at Lady Musgrave Island. Photo: Ryan Pearson
By Ryan Pearson
Scientists claim that coral reefs are dying, they're disappearing, going extinct! There are even claims that they will disappear entirely by the end of this century. This would be an astounding 'accomplishment' by the human race... the first to wipe out not only a species, but an entire ecosystem. The sad part is, my first trip to the Great Barrier Reef, a single day of diving, has illustrated to me just how dire the situation is.

In virtually all of the shallows around Lady Musgrave and its surrounding islands there were giant beds of dead corals, often barren of other fish life - a strange phenomena considering coral reefs reputations as the most biologically diverse ecosystems on Earth. Down deeper it was still possible to see some thriving corals and see why these ecosystems are so important, but the level of death and destruction was truly astounding.
More dead corals at Jackson's Bommie. Photo: Ryan Pearson
Oceans are known as the 'sinks' of the planet, in that they act in some part to balance the damage we're doing by burning fossil fuels. They do this by reabsorbing some of the carbon we're putting into the atmosphere, carbon that had previously been buried over the process of millions upon millions of years. This acts in a small way to reduce the impact we have on increasing the global mean temperature through the greenhouse effect... but it does not prevent it, and has some considerable side effects of its own.

Global mean temperatures are still rising, and as a result of this there is less calcium in the oceans available for corals and other marine invertebrates to use to create their skeletons. This obviously leads to widespread damage to a multitude of species. Furthermore, by reabsorbing the excess carbon in the atmosphere, the oceans become more concentrated in carbonic acid, which also acts to dissolve the skeletal structures of the corals and many invertebrates. A breakdown of the chemistry of ocean acidification can be found here.

It's pretty clear to me, and to most scientists in the world that these things are occurring, and it's a terrible tragedy - in fact, I don't think there's really much debate on the subject - but someone out there may be asking "why does it matter if coral reefs disappear"? Well, outside of the immense enjoyment that coral reefs bring snorkelers and scuba divers worldwide, they also play an important role in other parts of our lives, and the health of the planet as a whole. If you don't believe me... look it up for yourself, the article I've linked to at the top is a great starting point.

No comments: