We were snorkeling just outside the channel at Parrot Tree Plantation the other day, and maybe because we were on the surface most of the time, we noticed something really sad. Most of the pillar corals are just gone. They’re dead rock. Not bleached, or stressed, but lifeless, algae covered rock. There is none of the vibrant color and life that was in them just a few short years ago. It's heartbreaking.
SCTLD is to blame. Stony Coral Tissue Loss Disease has been destroying stony corals, especially pillar corals, since it swept into the Caribbean Sea back in 2018. Check the Caribbean dashboard for the stats (and to make reports of SCTLD sightings). SCTLD is one of the deadliest diseases threatening coral reefs, to date. It is a fast-moving, transmissible condition, but thankfully, it can be treated with antibiotics and marine epoxy.
Treating corals with SCTLD is not easy, though, and at the rate the disease is spreading all throughout the Caribbean, most of the affected corals are going to vanish, just like that. We might be able to save some of the larger, more reproductive specimens, but the prognosis for the bulk of stony corals is not looking good.
Thankfully, some dive sites appear to be uninfected, thus far. For example, check out these healthy pillar coral specimens from one of the sites we frequent up in Port Royal, taken just a couple weeks ago.
Divers need to do our part to ensure that we are not unwittingly spreading the bacteria, by disinfecting our dive gear thoroughly. The AGGRA recommendations call for disinfecting dive gear between dives if any equipment comes in close contact with any colonies affected by SCTLD. Which means divers in affected areas need to start taking SCTLD into account when planning any dives, so that divers are going to dive sites with little or no SCTLD exposure first. That way, divers can ensure we are not helping to spread the bacteria to new spots.
We can also take pictures, submit reports, and help to raise awareness of this devastating disease. If you’re planning on visiting a dive shop in the Caribbean, consider asking if they have any SCTLD mitigation efforts in place, and see if they need any supplies. Antibiotics are not readily available in all places, especially Caribbean islands, and marine epoxy is expensive, making these types of harm reduction programs difficult to implement without external support. Additionally, recent research suggests SCTLD could be caused by infected ballast water, suggesting a need for regulation of ballast water transfer.