This is a follow-up publication on Stony Coral Tissue Loss Disease. It describes the findings in the coral reefs in the Cayman Islands during a week in mid April, 2024. The travel to the island was reasonably easy and the accommodations onboard the live-aboard cruise were good. The conditions of the reef life and tropical fish however was disheartening. We have a big problem.
The featured image was made from a view of the sunset from the port on Grand Cayman island. The sunset may be symbolic of the future diving in the Caribbean. I hope that there is a recovery in the future.
As reported in four previous posts (Death in Paradise), there is a continuance of even greater proportions seen during this trip. I reported on the findings on the reefs around Roatan Island off the coast of Honduras two years ago. The condition of the reefs showed considerable loss of the polyp life because of Stony Coral Tissue Loss Disease (SCTLD). It was quite extensive and showed nearly 70% loss of life. At night the coral showed a significant loss of fluorescence because of the large dead areas of coral polyps. During the day one could see the areas of exposed stony skeleton of the reef.
The reef at multiple sites of the Cayman Islands including Grand, Little and Brack, has been devastated by the disease. The population of the reef fish is also significantly diminished. I did not make a count of the fish or of the areas of dead coral. Because of the extent of the dead coral there was no reasonable way for me to make an accurate comparison. It was very distressing. With the option to make 20 dives I made only 12. There was nothing worthwhile to see. I would estimate more than 80% to 90% loss of polyp life.
In conversation with other experienced divers on board the ship they said that they saw similar conditions across many of the Caribbean islands from Bonaire to the Mayan coast. Generally, they were unaware of the cause of the polyp depletion but said that it looked the same as in the Caymans. The less experienced divers were unaware of the problem and were happy to be in the warm water (85.5 degrees F). There was still some interesting wildlife but is was very reduced when compared to the concentration I had seen as little as 5 years ago.
There was still life in the Caribbean but it may be below the 100-foot depth accessible for divers and also for much of the live that requires light. The life forms that were readily apparent were mostly bottom feeding animals. Sponges and soft fans were still alive and did not seem to be affected by the SCTLD.
The effects upon the economy that are a result of reef polyp loss are not readily available, however, many of the recreational hospitality workers are questioning their future employment opportunities. I suspect that there may be some resistance in these businesses to make these issues more public.
There has been some publication of the research into the cause of the disease and it seems that researchers have identified an infection. “Results suggest that the bacterial community may be involved in SCTLD, but other members of the holobiont (i.e., viruses and Symbiodiniaceae) may contribute to lesion progression”.1, 2
Vectors and process of viral action is not yet publicized 3. One should not expect a recommended solution for a cure until much further research will be done. I anticipate that it may take decades and that the reef corals will not survive at the current rate of disease progress. This has a direct impact on the southwest coast of Florida.
If you have observed the effects of SCTLD in other areas of the Caribbean or other places in the world please engage in the SCTLD dialogue in the discussion board.
References: Where 2. and 3. are specifically related to work done in Florida reefs.
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