An epidemic that has killed all the black sea urchins in the Gulf of Eilat threatens to destroy the coral reef, a study released on Wednesday found.
“This situation is unprecedented in the entire documented history of the Gulf of Eilat,” the Tel Aviv University study states.
It notes that extensive mortality is also occurring in other countries in the region, including Jordan, Egypt, Saudi Arabia, Greece and Turkey.
The source of the pandemic is thought to be a pathogenic ciliate parasite that eradicated the entire sea urchin population in the Caribbean in the 1980s, damaging the coral reefs there irreversibly, the researchers wrote.
The current epidemic was first discovered in the Mediterranean but quickly reached the Red Sea, where it is spreading at an unprecedented rate.
Within a few months, the epidemic killed all the black sea urchins in the Gulf of Eilat; they died within two days of falling ill.
Sea urchins are considered essential for the healthy functioning of coral reefs, the study says.
“At first we thought it was some kind of pollution or poisoning, or a local chemical spill from the industry and hotels in the north of the Gulf of Eilat, but when we examined additional sites in Eilat, Jordan and Sinai, we quickly realized that this was not a local incident,” said Omri Bronstein of Tel Aviv University, who led the study.
“All findings pointed to a rapidly spreading epidemic,” he said.
He noted that similar reports are coming in from colleagues in Saudi Arabia.
“Even sea urchins that we grow for research purposes in our aquariums at the Interuniversity Institute [for Marine Sciences in Eilat], and sea urchins at the Underwater Observatory Marine Park in Eilat, contracted the disease and died, probably because the pathogen got in through the pumping systems,” Bronstein said.
Within two days of contracting the parasite, a healthy sea urchin becomes a skeleton with massive tissue loss. While some corpses are washed ashore, most sea urchins are devoured while they are dying and unable to defend themselves, which could speed up contagion spread by the fish who prey on them.
The papers were published in Frontiers in Marine Science and Royal Society Open Science.
“As with COVID-19, at this point, no one knows what will happen—will this epidemic disappear by itself, or will it stay with us for many years and cause a dramatic change in coral reefs?” Bronstein said.
An urgent report describing the situation was submitted to the Israel Nature and Parks Authority, and emergency steps for saving the coral reef are being considered.
