Disease Outbreak
A devastating disease outbreak among sea urchins is threatening coral reefs worldwide, with the outbreak spreading to the tropical waters of the Coral Triangle, extending to Southeast Asia and the Great Barrier Reef, warn Israeli scientists in the journal Current Biology.
Impact on Coral Reefs
The pathogen, rapidly and aggressively killing, has caused entire populations of urchins to disappear within two days, making it difficult to assess the scale of mortality, says Omri Bronstein, a zoologist at Tel Aviv University and the Steinhardt Museum of Natural History.
The disease, is thought to be spreading eastward, towards the tropical waters of the Coral Triangle, extending to Southeast Asia and the Great Barrier Reef.
Bronstein describes the sea urchin die-off like a "lawnmower" for coral reefs, as they remove algae that would otherwise block sunlight from reaching and sustaining the corals.
In the Gulf of Aqaba, there are no other animals that perform this crucial role, and the algal cover has grown increasingly dense.
Investigation and Mapping
When the die-off began in the Red Sea, the scientists initially considered pollution or some other catastrophic event as a cause, Bronstein says.
The Israeli research team is now collaborating with scientists in the region to map the outbreak and gather more details, collecting DNA samples from different water bodies to assess the pathogen's interactions with its marine environment.
Initial Outbreak
The outbreak was first detected a year ago in the Gulf of Aqaba, part of a series of sea urchin die-offs that have taken place in the Red Sea, the Arabian Peninsula, and Reunion Island off Madagascar.