Read more at The Guardian

Marine Pandemic Causes Mass Sea Urchin Deaths

• Extreme Die-Offs: An unknown marine pandemic is causing mass deaths and bringing some species of sea urchin, particularly the Diadema africanum genus, to the brink of extinction globally.
• Devastating Population Loss: Since 2021, losses have been dramatic, including a 99% population decrease in Tenerife (Canary Islands) and a 90% decrease off the Madeira archipelago.
• Global Spread: Mass deaths of Diadema species have also been detected across widely separated regions, including the Red Sea, Mediterranean, Caribbean, and western Indian Ocean.
• Unknown Cause, Human Involvement Suspected: While the exact cause of the disease is unknown, researchers believe human activity is “probably involved” in its distribution. Current theories for transmission include shipping, changes to currents, and abnormal wave activity.

Ecological Impact of Urchin Loss

• Ecosystem Engineers: Sea urchins are vital “ecosystem engineers” that significantly modify their habitat through their activity.
• Coral Reef Protection: Their primary ecological role is grazing on algae, which prevents algal overgrowth and promotes the survival of hard coral, which is a critical habitat for thousands of marine species.
• Cascading Effects: The loss of urchins is having serious negative ecological consequences, such as in Caribbean reefs where coral cover has halved and algal cover has increased by 85%.
• Uncertain Future: Only a few isolated pockets of water have not yet been affected, and scientists are unsure how the pandemic will evolve or if it will spread to crucial populations in Southeast Asia and Australia.