Recent research has identified the parasite Philaster apodigitiformis as the cause of a significant die-off of long-spined sea urchins (Diadema antillarum) in the Caribbean, leading to population declines of 85% to 95%. These sea urchins play a crucial role in maintaining coral health by grazing on algae that threaten coral reefs. The epidemic, first reported in January 2022 starting in St. Thomas, spread rapidly across the Caribbean, severely affecting marine ecosystems.
Marine ecologist Ian Hewson led an international team that used genomic analysis to detect this parasite in infected sea urchins. Their findings establish a connection between P. apodigitiformis and mass mortality for the first time in invertebrates. Although treatment for this infection remains uncertain, understanding its identity could help in developing health maintenance strategies for Diadema populations being bred for replenishment.
The study highlights the importance of these sea urchins in coral reef ecosystems, as their absence could lead to the overgrowth of harmful algae and subsequent coral death. Additionally, the research prompts investigation into historical die-offs in the 1980s, which also devastated sea urchin populations but occurred without a known pathogen.
