As recent as 30 years ago there was almost no available information or data on coral diseases. But, in the 1970’s an outbreak of white plaque disease decimated many Caribbean reefs, and opened up scientists to the realization that coral diseases are becoming more widespread and pronounced around the globe. Since that time, more than 30 new coral diseases have been identified, although still very little knowledge remains on many of the causes, transmission, or tenacity of the diseases being identified.
There are some things that scientists do know for sure, coral diseases act much like human diseases. Think about times when you would expect to get sick. . .probably it is when you are stressed, exposed to unclean conditions, or exposed to others who are sick. It is the same with corals. As corals become more stressed by changes in global ocean temperatures and chemistry, introduction of excess nutrients and novel chemicals, or changes in the balance of organisms on the reefs, diseases become more active and deadly. Waste water run-off, fertilizers, deforestation, and other land based activities can make waters ‘unclean’ allowing bacteria or other harmful microbes to flourish, increasing the incidences of coral diseases. And lastly, a reduction in reef diversity leading to species uniformity on reefs means that outbreaks happen more often and are more widespread.
Photo credit to New Heaven Dive School