The Cayman Islands Department of Environment stated that Diadema antillarumThe long-spine ocean urchin, also known by the name “long-spine sea Urchin”, is reportedly experiencing another high death event in the Caribbean. There are reports that the events started in St. Thomas USVI early February, Jamaica early March, and Mexico and Dominica in the past few days. A regional collaboration is the key to success. Diadema Response Networka quickly formed to investigate and track the cause of this Diadema death event.
According to a Cayman Islands Department of Environment press release, Dr. Croy McCoy, Senior Marine researcher, stated that sea urchins and more specifically the long-spine sea Urchins, are keystone grazers responsible for controlling the growth of algae on our reefs. Long-spine sea Urchins play an important part in the removal of algae and maintaining the health our coral reefs ecosystem. He said that they are the lawnmowers in our coastal seas. They clear space so other organisms like baby corals can attach and grow.
The long-spine sea urchin was discovered in the western Atlantic basin and the Caribbean basin between 1982-1983. Diadema antillarumA sudden, major death occurred. There was no cause. The population is still struggling to recover, reaching less than 20 per cent of its prior population status. Regarding the latest mortality figures, Dr. McCoy said that it is sad to see yet another high mortality event in the Caribbean region of this critically important urchin for the ecological function of our coral reefs.” “Additionally, the reported rate of death for large numbers of these urchins is comparable to that of 40 years ago.
The Cayman Islands have yet to report any unusual deaths from these sea urchins. It does however overlap with another serious threat to coral reefs that has made its way across the Caribbean from Florida in 2014. Stony Coral Tissue Loss Disease is an aggressive coral disease that can affect 20+ species. Some coral species are affected 60-100%. This disease was first discovered on Grand Cayman’s coral reefs in June 2020. It spread quickly throughout Grand Cayman within a little over a year. It has not been reported on the coral reefs at Cayman Brac and Little Cayman.
SCTLD Response Team Coordinator, Tammi Warrender explained how the community can help proactively to address the threat to our local Diadema populations.
She said:
We need to hear from the public in order to respond to this threat immediately and to collect, organize, and share data with the scientific community to find possible solutions. The community should immediately report any unusual sightings, especially dead or group of dead sea-urchins. We will also appreciate any reports of healthy sea urchins.
Dead or sick urchins may not be able attach to their feet and may be floating and/or losing spine movement. Dead and sick urchins may have their skeleton exposed and may lose their spines.
Download our EpiCollect app for divers, snorkelers and boaters as well as fishers, fishermen, and beach walkers Urchin Health CaymanReports can be submitted quickly and efficiently to DoE. You can also WhatsApp or send a report by text to 926-0680, or email [email protected]