Coral reefs all around the world are in crisis.  The reasons for this are many and may or may not be specific to localized areas.  While climate change, pollution, , agricultural runoff and harsh weather can affect coral reefs anywhere, coral in the Western Atlantic appears to be under attack from a new threat – stony coral tissue loss disease.  What is stony coral tissue loss disease?  In this article, we’ll find out.

Origins & Definition:

Stony coral tissue loss disease (SCTLD) was first encountered off the coast of Florida in 2014.  Within five years it had spread throughout the Florida Keys and made its way into the Caribbean Sea.  

Suspected to be caused by an, as yet unknown, bacterium, (SCTLD) is typified by the destruction of the soft tissues found in several species of stony coral.  The disease first appears as white lesions on the coral surface.  Eventually the affected tissue sheds away and the skeleton is left to die unprotected.  The disease can spread quite rapidly and can kill off a colony in as little as a week to a few months.  

What Corals Are Most Affected:

Not all corals are affected by stony coral tissue loss disease.  Some species, such as staghorn and elkhorn corals, appear to be immune.  However, there are known to be at least 20 species of hard coral that can be affected.  Most susceptible are the meandroid types of coral such as pillar, elliptical star and maze corals.  Brain corals are also prone to infection.  66 to 100% of all affected corals capitulate to the disease.

What Is Being Done To Monitor Stony Coral Tissue Loss Disease:

Because so little is actually known about stony coral tissue loss disease, monitoring its spread is still an important part of understanding how the disease works and what can be done to control it.  Through the use of surveys and observational reports, monitoring programs have appealed to divers to help track both healthy coral populations and those affected by the disease.

What Is Being Done To Stop Stony Coral Tissue Loss Disease:

Scuba divers have been urged to not visit healthy coral sites after diving in diseased areas without disinfecting their gear first.  Boaters are also reminded to pay close attention to ballast water management in order to protect vulnerable coral populations.

A program in Florida is trying to prevent the spread of stony coral tissue loss disease by creating physical barriers between healthy and diseased sections of corals.  This involves inserting a chlorinated epoxy resin directly into the coral to prevent the spread from an affected part to adjacent healthy sections.  

There has also been the production of an antibiotic gel which can be applied directly to affected corals.  In experimental tanks it was found that dosing the water with antibiotics was able to control the disease.  Although not practical in open water treatment, this does lend support to the bacterial cause hypothesis. 

There is also an effort underway to transplant healthy corals into captivity.  These populations could be replanted into the wild once the disease is eradicated.  This is being done both by capturing fertilized gametes and allowing them to grow in the laboratory as well as harvesting and transplanting mature specimens.

It’s hoped that learning more about the disease will eventually lead to its elimination.  But for now, much more research needs to be done and those scuba diving in Roatan need to do their best keep our reef safe.