Scientists demonstrate new measures for coral disease

(CNS): As scientists continue to research the causes of stony coral tissue loss disease, they are developing various measures to help control its spread. Last week during a workshop on Grand Cayman for scientists on the front line of the fight against SCTLD, a devastating pathogen attacking reefs across the region at an alarming rate, researchers from the University of North Carolina Wilmington demonstrated a new treatment and the results of their work.

The team from UNCW, led by Dr Blake Ushijima, has developed a probiotic treatment, and very early results suggest that it is more effective than the antibiotic paste currently being applied to infected corals, offering hope that this deadly disease can be countered. The research is in its very early stages, but there is some indication that a deficiency or lack of certain bacteria could be making corals vulnerable to the still mysterious disease.

Speaking to CNS last week, Ushijima explained that the scientific world is still struggling to pin down what is causing SCTLD and exactly how it infects corals. While there are some theories, it is likely to be a multitude of things that are simultaneously impacting the coral, made worse by the increasing sea temperature. He explained that corals are exposed to a variety of viruses and bacteria in their warm wet world. Some of these pathogens can hurt the coral, while others are harmless or even helpful, and the challenge is working out which is which.

Studying things under the sea adds to the challenge for scientists trying to learn as much as they can about this latest and worrying threat while using what they already know about corals to try to protect them from it. “There are a lot of variables that you are trying to study, and you are doing all of this in dive gear underwater,” he noted.

Ushijima said that, just like humans, corals need good bacteria to be healthy and this is probably why the probiotic mixture they have developed is working. He said that by studying the corals that are less impacted and appear more resilient to this disease, they began to see that they had more helpful bacteria and therefore developed the plan to give corals infected by the disease a probiotic.

Kelly Pitts from the Smithsonian Marine Station, who is working with Ushijima, said the difficulty had been working out how to get that probiotic onto the corals in sufficient quantity and to make it stick for long enough to help. They initially applied it in a paste form the same way the antibiotic mixture has been applied here in the Cayman Islands and around the region but found that putting it in a bag worked much better.

“Whole colony treatment appears to be working better than any other method tried so far,” she said, and explained how the divers place very large weighted bags over coral heads and fill them with the treatment.

Given that SCTLD is a new pathogen, scientists around the region are collaborating and sharing information because they are racing against the clock to save the already stressed coral reefs and try to contain the virus. While this disease currently appears to be confined to the Caribbean and the Western Atlantic, there are concerns that it could be carried through the Panama Canal and begin infecting corals worldwide.

The demonstration this week was part of a four-day seminar focused on how to tackle SCTLD. It included Cayman’s first Coral Fest, hosted by the Department of Environment, to raise awareness locally of the critical importance of coral reefs to the Cayman Islands and the many threats to their survival.

In a short address at the event, Premier Wayne Panton said he began scuba diving as a teenager after getting a summer job in a dive shop. Noting the changes he has seen in the underwater world here since then, he said that efforts to protect the reefs have to be stepped up, given the number of threats they face. He added that the PACT Government remained committed to protecting Cayman’s marine environment because of its importance to the local culture and heritage as well as tourism.

See the video below of efforts to apply coral probiotics: