Caribbean reefs rely on the long-spined sea urchin, Diadema antillarum, to control algae growth and maintain coral health. A decline in sea urchin populations after die-off events has led to increased algae levels, reducing coral cover and ecosystem stability. Restoration efforts include methods like “bio balls” and artificial reefs to revive urchin populations. Divers can help by avoiding disturbing sea urchins and minimizing the spread of parasites.