Published: 14th December 2009
ACIDIFICATION of the oceans was today described at the Copenhagen Summit as "a major threat to marine life and our food supply".
Extra carbon in the atmosphere is being absorbed into the seas, lowering the pH value with potentially harmful consequences for coral, fish stocks and ultimately people, warned UK environment minister Hilary Benn.
Such changes are part of a varied range of environmental impacts to which modern coral reefs are being exposed. A critical question is how these impacts are expressed in terms of a coral reefs ability to keep growing, or whether they are moving to states of rapid erosion
A major new study by Manchester Metropolitan University aims to create an accurate, new measure of coral reef health based on the rates at which corals are adding new calcium carbonate to their structures.
Studies suggest that reefs are worth more than £60bn annually, protecting communities from storm damage and creating ecosystems essential for food production.
Professor Chris Perry, of the University’s Centre for Earth and Ecosystem Responses to Environmental Change, is leading a Leverhulme Trust International study to develop a more effective and rapid method of assessing the carbonate ‘budgets’ of reefs.
Each ‘budget’ will show a balance sheet of the amount of carbonate produced and removed from a reef, thus allowing changes in net reef carbonate production rates over time to be monitored.
His team will partner leading marine scientists in Australia, New Zealand, Canada and the US, in a bid to create a toolkit to more accurately assess whether a reef exists in a state of net accumulation, stasis or erosion.
It is often a more complex assessment than sometimes reported, he says, requiring assessments beyond simply looking at the amount of coral on a reef. In particular, we need to know how much carbonate is being produced by other reef species, especially calcifying algae, and how much is eroded away by fish and urchins.
"The relative roles of all the carbonate cycling processes are rarely considered in existing reef health assessments and standardised approaches to quantifying carbonate budgets do not exist," writes Professor Perry in the Leverhulme newsletter.
Professor Perry was recently appointed Chair of the International Association of Geomorphologists Working Group: ‘REEForm: Reef and reef landform responses to climatic and environmental change’.
Click here for more about the Centre for Earth and Ecosystem Responses to Environmental Change at MMU.