In 2022, long-spined sea urchins in the Caribbean faced a dramatic decline due to a scuticociliate parasite, closely related to Philaster apodigitiformis. This species, Diadema antillarum, plays a vital role in maintaining coral reef ecosystems by consuming algae, thus allowing coral to flourish. Researchers quickly identified the parasite as the cause of the mass die-offs, which began in St. Thomas and spread to other Caribbean locations, including Florida, within months. Though the die-offs seemed to halt by December 2022, there have been recent reports of new fatalities among sea urchins in the Cayman Islands and U.S. Virgin Islands, raising concerns about a resurgence.
Scientists have actively studied the parasite’s characteristics and its impact on marine health, recalling a similar mortality event in 1983 that decimated urchin populations, leaving long-term effects on coral ecosystems. Current research, backed by institutions like UF/IFAS, involves environmental assessments and attempts to rear healthy urchins for future restoration. Despite the knowledge gained from these events, questions remain about the parasite’s emergence and historical ties to past die-offs. Continuous monitoring will be crucial for safeguarding urchin populations and coral reef vitality.
