When someone mentions the words climate change, the first thing that may come to mind is an overall increase in the earth’s temperature, known as global warming. Global warming is expected to lead to more frequent and extreme weather events and a risk of sea level rise that could displace millions of people globally.
An effect of climate change that is often overlooked is a process known as ocean acidification: the gradual decrease in ocean pH, caused by increased absorption of carbon dioxide (C02) by the world’s oceans. This can interrupt essential physiological processes such as respiration and calcification, which not only prevents the growth and survival of organisms with a calcium carbonate (CaCO3) skeleton such as coral reefs and echinoderms, but also accelerates the decline of the structure left behind.
This process has been going on since the beginning of the industrial revolution (1760). Since then, the world’s oceans have undergone a 30% (0.11pH) decline in pH. At first this may seem like a small and rather insignificant change, but all living organisms on earth are very sensitive to changes in pH, including humans. Human blood usually ranges from 7.35-7.45pH, but a 0.1 decrease from this variation can have severe consequences on our health through a process known as “acidosis”. When blood is maintained at the normal (basic) pH range, we are more resilient to illness and are able to lead a more active lifestyle.
The same principal goes for the world’s oceans. When pH is maintained at around 8.1, there is increased ecosystem resilience to both natural (wind damage, coral disease and bleaching) and human impacts (pollution, introduced species, anchor/diver damage). If we knew our own bodies were going through the process of acidosis, we would surely do something to correct it. When we realize the similarity of our own blood with the world’s oceans, it becomes apparent that this is the time to act on this 0.1 decrease in global pH before the effects become irreversible.
A recent report put together by Matthew Huelsenbeck in September 2012 ranked the Turks and Caicos Islands as the third most vulnerable nation to food security threats from ocean acidification and the 14th most vulnerable from the combined affects of climate change and ocean acidification. Vulnerability was determined by adding a countries exposure to the threat of ocean acidification and climate change, dependence on seafood as a source of protien, and the lack of adaptive capacity towards the threats.
Whilst stopping off in South Caicos, we had the opportunity to chat with Dr. Edward Hind from the School of Field Studies (SFS). Dr. Hind concentrates on social science issues to do with fisheries management and conservation. He informed me of this report and the fact that locals in Turks and Caicos are highly dependent on the queen conch (Strombus gigas), amongst other resources found on coral reefs.
The queen conch is a gastropod (sea snail) which is intensively harvested for its muscular foot (food) and beautiful shell (ornamental exports). It is also a candidate for the CITES endangered species act and secretes a calcium carbonate skeleton shell, as well as living in coral reef habitats susceptible to ocean acidification.