https://phys.org/news/2018-07-previously-overlooked-coral-weaken-degraded.html

Scientists at the Georgia Institute of Technology conducted the research and reported it July 26 in the journal Ecological Applications. The research was supported by the National Institutes of Health, the National Science Foundation and the Teasley Endowment to Georgia Tech.

"Once the reefs are down and nearly out, these snails are piling on," said Mark Hay, a Regents and Teasley professor in Georgia Tech's School of Biological Sciences. "The Porites coral is kind of the last man standing, the last hope for some of these reefs coming back, and they are the ones these snails selectively prey on. As you get fewer and fewer corals, the snails focus on the fewer and fewer of these colonies that remain. This is part of the downward spiral of the reefs."