Pristine coral reef. mainly Acropora sp. with aggregation of blue-green chromis. Chromis viridis. … [+] Pohnpei. Federated States of Micronesia. (Photo by: Andre Seale/VW PICS/Universal Images Group via Getty Images)
Micronesia is a series of several islands northeast of Australia and consists of sovereign nations and U.S. territories including Guam. Micronesian islands are surrounded by coral reefs and atolls and their beaches are often comprised of coral sand. Thus, corals are a major component of the region’s tourism industry and ecology. However, new research shows that these corals — which are already threatened by climate change — are now afflicted with a new disease.
For seven years, scientists examined reefs across the Indian and Pacific Oceans and found that this new coral disease, termed grey-patch disease, occurs only in Micronesian reefs. When a coral is infected with this disease, a grey film of cyanobacteria overtakes the coral’s tissue. It changes the microbial community of the affected corals and appears to occur after corals experience a bleaching event and are more susceptible to infections. Altering the microbial composition of a coral can affect its survival and make it vulnerable to other stressors. The researchers found that grey-patch disease occurs across 18 coral species, but progresses slowly enough that healthy coral tissue can overgrow the grey cyanobacteria film.
A coral impact by grey-patch disease.
Coral diseases have become more common over the past decade and are causing mortality across numerous species of reef-building corals. And, this finding comes on the heels of the rapid spread of a different coral disease halfway across the world in Florida. Stony coral tissue loss disease, the source of which remains unknown, is occurring across 96,000 acre expanse of reefs along Florida’s southeast coast. Similar to bleaching, when infected with this disease, stony corals lose all their living tissue and turn white. The disease has grown exponentially since 2014 and has driven researchers to take healthy stony corals into the lab to grow them to withstand the disease so that they may one day be re-introduced to their native waters.