Coral reefs at risk of damage from land-based microbes as well


Scientists have found evidence of land-based microbes including bacteria and fungi being probably responsible for damage to coral reefs beyond the traditional risks including ocean acidification, global warming and climate change.

Researchers led by scientists at University of Minnesota, Duluth, have published findings of their study in Applied and Environmental Microbiology wherein they have suggests that coral reefs may be undergoing further damage from land-based microbes. These land-based microbes including bacteria and fungi could be introduced into the waters where coral reefs are present through outfall from sewage treatment plants and coastal inlets.

For the study scientists collected water samples from coastal inlets, and from oceanic outfall effluent from water treatment plants along Florida’s southeastern coast, as well as from water and coral tissues in reefs. They determined that certain bacterial species and fungal families were present both in the land-based sources and in water and tissues within the coral reefs.

Previous studies failed to find on other reefs the microbes that appear both on nearby land and on reefs in this study and this effectively means that those microbes have invaded these reefs.

Scientists used techniques called “high throughput next generation DNA sequencing” and to analyze each of the water samples to identify and quantify the bacteria and fungi living therein. They then used software called SourceTracker to evaluate and quantify the potential contributions from each of the land-based sources to the reef.

Authors of the study have called for further experiments to prove the hypothesis. However, if the hypothetical invaders actually are invaders, these microbes will have almost certainly changed the community structure of the reef microbiome. These invaders would likely disrupt the ecology of the animal and plant communities of the reef, and since the coral depends on all of the above for its health and sustenance, it would likely be harmed as well.