Assessing the vital signs of coral reefs

By Lucy Brake - 21 Mar 2011 23:49:0 GMT
Assessing the vital signs of coral reefs

Coral reefs play a crucial role as one of the world's key ecosystems. Home to around 25 percent of all species of marine life (including molluscs, crustaceans and fish) and occupying only 1/10th of one percent of the ocean surface, they form one of most varied ecosystems found.

Coral reefs are very fragile and susceptible to slight changes in water temperature. Recent research has shown that coral reefs are significantly suffering from the impacts of climate change, the acidification of oceans, poor fisheries management and pollution from urban and agricultural runoff which encourages over-running of the reefs by algae and the bleaching of the reefs themselves. The World Resources Institute has recently analysed the world's coral reefs and concluded that almost 75 percent of reefs are threatened by these human-induced changes.

An important part of understanding the impacts humans are having on coral reefs is gaining knowledge of their biological productivity. However, in the past measuring how productive coral reefs are has been time-consuming and expensive, requiring ongoing measurement as scientists need to trace the changes in the dissolved oxygen of seawater as it moves over the reef.

Now researchers at the University of Miami Rosenstiel School of Marine & Atmospheric Science have come up with a novel way to actually take the pulse of coral reefs. This new tool monitors the vital signs of a coral reef and ultimately assists scientist to understand how global warming and other threats are impacting the health of coral reefs.

Researchers based at the University of Miami have tested the theory that by combining the measurement of consumption rates and dissolved oxygen levels they could monitor a reef's health.

They measured what the balance was between how much new organic material was being produced and how much of that organic material was being consumed by the heterotrophs (or organisms that cannot produce their own food and rely on plants and some bacteria for survival). They found that this then provides a pretty clear picture of the health of the coral reef ecosystem.

This new tool opens up the potential to be able to make long-term assumptions about the health of coral reefs based on different scenarios and provide more definite management options for protecting this important ecosystem.