Recipe for rescuing our reefs
The colourful world supported by coral reefs is under threat as oceans absorb greater quantities of carbon dioxide, says Rod Salm. In this week's Green Room, he says we must accept that we are going to lose many of these valuable ecosystems, but adds that not all hope is lost. I've been privileged to see many of the world's finest and least disturbed reefs. Mine were the first human eyes to see many of the remotest reefs at a time when we really could describe them as pristine. I would never have dreamed that they were at risk from people, far less than from something as remote then as climate change.
Today, despite the doom and gloom one reads so much ...view middle of the document...
This removes carbonate from the water; and carbonate is an essential building block for calcifying organisms, like corals, molluscs, sea urchins and many other important creatures that live on reefs or help to build them. Too much carbonic acid lowers the natural pH balance of the oceans, causing acidification, which wreaks havoc on marine habitats and species.
Just imagine all the colour and vibrancy of coral reefs fading away into fuzzy, crumbling greys and browns, and you're left with a coral graveyard that could become the norm if we don't address the threats to our oceans. We need to find ways to convince people to take action, but that is a major challenge.
Given the difficulties that many coral reef managers around the world have in controlling such pressing direct threats as destructive fishing, overfishing and pollution, they are understandably hesitant about taking on an issue that they feel is beyond their ability and mandate to tackle. Climate change is often seen as too daunting and too global for them to address, and too abstract for them to communicate.
Fortunately, in some respects, the sudden and startling onset of mass coral bleaching linked to warming seas has changed that a little. We have developed and are applying some straightforward, practical actions to design marine protected networks and zone the individual sites to protect areas that are naturally resistant to bleaching. These areas are key, as they provide larvae that are transported to more vulnerable reefs where they settle and enhance recovery. The high visibility of coral bleaching makes this relatively easy to see and study, but ocean acidification is difficult to detect by sight alone. It is creeping, progressive, and insidious - likened by some scientists to osteoporosis of the reef - a weakening of the reef structure that makes corals more vulnerable to breakage from waves and human use.
We simply do not know yet whether we have reached or surpassed the point of no return for some coral species. If current emission trends continue, we could see a doubling of atmospheric CO2 in as little as 50 years. This would lead to an unprecedented acidification of our oceans that coral reefs would be unlikely to survive, a scenario that should spur us into action to try and find solutions. A significant lowering of ocean pH would mean potentially massive coral loss. That would lead to the death of countless marine species as well as the devastation of economies dependent on ocean health and productivity.
'Meeting of minds'
It would also mean the end...
