Friday, October 23, 2009

The other thing about climate change which people have just figured out...

Climate change isn't all about Global Warming. Most of the international media has been focused on that side of things because it was easier to study and easier to understand. Of course many still don't understand, but what recently has become quite obvious to scientists is that the other part of Climate Change which may be even more serious for small island states like Antigua and Barbuda is Ocean Acidification. What the heck is that right? Well Ocean Acidification is a phenomenon where the acidity levels of the ocean are rising rapidly because of the huge amount of CO2 (Carbon Dioxide) that the oceans are absorbing. Scientists used to think that by absorbing the CO2 the ocean was helping Climate Change by keeping it out of the atmosphere, but recent studies showed how much higher levels of CO2 in the ocean has caused a major increase in the acidity of the ocean which in turn has had a huge impact on the ability of shell and plate making animals to thrive. These shells and plates are made out of calcium carbonate (CaCO3) which has a hard time forming with the increased acidity. Most food chains in the ocean would collapse without the animals in that chain that produce shells and or plates. The organisms that make up coral reefs have had the hardest time dealing with ocean acidification and it's my opinion that this is the main reason that our coral reefs have been so decimated. There are a huge variety of reasons that the decline in coral reef is disastrous for Antigua and Barbuda.

1- with higher sea levels and less of a barrier reef there are certain areas around the nation that have had massive coastal erosion. Spanish Point also known as "White Bay" in Barbuda was once upon a time the favorite beach in Barbuda for locals and visitors. Over the past 15 years it has slowly disappeared with most of the erosion happening over the past 24 months. This sort of dramatic coastal erosion is most common where big Atlantic swell meets barrier reefs. As those reefs degrade more wave action and current meets the shoreline. Barbuda is most susceptible to this.

2- With coral reef facing increased acidification, they are less likely to grow. With other pressures like over fishing their survival is less likely. The entire inshore shelf fishery of a small island state will collapse without proper management if the reef is allowed to perish.

3- With less coral and fewer fish there is less sand being produced by herbivore fish. As has been talked about in this blog (click here) parrot fish and other such algae eating fish produce sand every time they bite algae off the coral. With less coral and fewer fish we have less sand being produced. With more sand being mined from our beaches and less of it being produced you don't have to be that smart to imagine what happens with higher sea levels and less barrier reef protecting the shores.

The time for extreme measures on protecting the reef is now, and I hope the government here get's their act together on the NEMMA. Please have a look at this video on ocean acidification narrated by the award winning actress Sigourney Weaver and put together by The Natural Resources Defense Council. (the first video is a long one really getting into the problem but the second vid is more to the point about coral reefs)

If this topic is very interesting to you, you may want to read more about it here.