Bionews Diadema Special Edition - Background and Current State
As previously mentioned, a new wave of long-spiced sea urchins (Diadema antillarum) die-offs are happening throughout the Caribbean, including reports from the northern three islands of the Dutch Caribbean.
In mid-February 2022, the first reports of extensive Diadema die-offs came in from St. Thomas of the U.S. Virgin Islands. Within a month, additional mortality events had been independently observed on Saba, St. Eustatius, Dominica, Jamaica, St. Vincent. On St Maarten, Diadema loss has been recorded on the dive sites Little Bay (fort Amsterdam), Frenchman’s Reef and Cowboy Reef (Indigo Bay). In Curaçao, the first sightings of diseased sea urchins were reported in early June. Two weeks later, more than 90% of the surveyed populations had disappeared.
On March 14th, 2022, St. Eustatius’ STENAPA was alerted by dive shops of a significant number of dead long-spined sea urchins in the artificial harbor area. After conducting a survey, it was determined that 44% of the urchins were dead and 6% appeared to be sick, leaving only half the population in a healthy state. The sick urchins were unable to stay attached to the substrate and had very minimal spine movement.
The video below was taken on St. Eustatius in March of 2022 by Kitmani Kitson-Walters (CNSI) and shows a number of sick and dying urchins across the seafloor.
A collaborative region-wide effort – the Diadema Response Network – has quickly formed to track and try to understand the cause of this recent die-off of Diadema (and possibly other sea urchins).
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