The following is a repost from the old Southern Fried Science WordPress blog. The original can be found here.
It was a story that could very easily have been written as science fiction. Gorgonian (sea fan) corals of the Florida coast were turning black and dying. The infectious culprit was something no one working on the reefs had encountered before. It was totally alien. The black rot spread across the Caribbean, decimating coral populations. By the time the contagion had been deduced, more than 50% of total sea fan tissue had been eradicated in the Florida Keys. It was one of the worst coral epidemics in recent history.
The culprit was indeed an alien, though certainly not extra-terrestrial. In fact, it was very terrestrial. Aspergillus sydowii, a globally distributed saprophytic soil fungus was the nightmare creature. Aspergillus causes a variety of diseases in humans and birds, but had not previously been recognized as a marine pathogen.