We need a better understanding of the processes and mechanisms that impact on corals and the reefs when sea temperatures rise to confirm the ultimate causes of their decline, says Dr Bythell. Although local actions to reverse the overall decline in reef health are probably not feasible, we need this better understanding to try to reduce or eliminate contributing causes. Some of the changes in the microbes environment could be locally managed, for example by reducing general pollution, cutting soil erosion into the sea which chokes the reefs, and avoiding harmful run-off from farming practices.
A key factor newly identified by the Newcastle team is the role of surface mucus secreted by corals. This seems to act as a shield, preventing disease-causing pathogens such as bacteria and some viruses from penetrating their tissues.
The reefs defensive mucus or slime is also at risk from stresses brought on by climate change. This seems to happen just at a time when some of the key functional microbe groups are changing, reducing the corals other defences and boosting some disease-causing bacteria, making them more virulent, says Dr Bythell.
If we want to protect and conserve these reefs for the future, we need to start acting now. And before we can do that we need a better understanding of the processes, says Dr John Bythell. The mass mortality of two of the dominant coral species in the Caribbean due to disease has been unprecedented in the last 3,000 years, which suggests a strong link to man-made activities.
The Newcastle scientists are concerned that despite the clear relationship to underlying factors affecting the reefs which cause the diseases and bleaching, and the important role played by the microbes, microbiology and coral cellular biology are investigated largely independently by different groups of researchers using different approaches. According to Dr Bythell, scientists attempts to identify the underlyi
|Contact: Lucy Goodchild|
Society for General Microbiology