Sea urchin die-offs are being recorded by researchers and divers near the shores of multiple Caribbean islands. According to the Atlantic and Gulf Rapid Reef Assessment (AGRRA), there aren’t any clues yet as to why the urchins are dying at such quick rates. The organization is especially concerned because other forms of marine life cannot thrive without the presence of the spiny sea creatures in the region’s waters.
“The long-spined sea urchin, is one of the most important herbivores on Caribbean coral reefs, removing algae and maintaining open space for coral growth,” the organization wrote on their website this past March.
A healthy population of sea urchins keeps invasive algae at bay and helps make way for native species to flourish. AGRRA and divers first noticed dying urchins this past February near St. Thomas, and by March, more sick and dying sea urchins were observed in nearby islands including Jamaica, Dominica, St. Vincent, and several others.
At first, the dying events were only noticed in Diadema antillarum, which are the black sea urchins that are easily identifiable thanks to their long dark spikes, CBS News reported. But then other species of urchins began to show signs of distress as well. A healthy sea urchin has spikes that cover most of its body and go straight up. On the other hand, sick urchins often lose their spines, and some of their inner tissue is revealed before they die, according to AGRRA.
The recent event is sadly not the first sea urchin “die off” in the region. Another one was recorded back in the early 1980s, and researchers did not understand why it happened at the time. Unfortunately, only some populations of urchins ever fully recovered from that episode, making the current dying event even more concerning.
There have been recent efforts to ensure a healthy population of sea urchins in the region. Late last year, the Florida Aquarium in Tampa spawned and eventually released almost 200 sea urchins to help protect the Florida Reef, the largest urchin restocking effort of the last 20 years, Axios reported.