Parasite causes mass sea urchin die-off, endangering coral reefs worldwide – study

JERUSALEM (Xinhua) — Israeli researchers have found a parasite is behind the mysterious massive death of sea urchins that endangers corals worldwide, according to a statement by Tel Aviv University (TAU) on Thursday.

In a new study published in the journal Current Biology, Israeli researchers found that the infection of scuticociliate, a parasite, caused the mass mortality of long-spined sea urchins in the Red Sea last year and those in the Caribbean in 2022.

The sudden die-off was initially spotted among thousands of sea urchins of the Diadema setosum species just below the shores of Israel's southernmost city of Eilat.

While trying to identify the cause, they found the deaths spread through the Red Sea to Oman, and even to as far as Reunion Island east of Madagascar in the Indian Ocean.

An estimated hundreds of thousands of urchins have died of it so far, the researchers concluded.

Feeding on the algae that compete with corals for sunshine, sea urchins are considered protectors of coral reefs.

The deadly urchin epidemic, if left unattended, will pose a major threat to corals across the oceans, the researchers warned.

"This is a growing ecological crisis, threatening the stability of coral reefs on an unprecedented scale," said TAU researcher Omri Bronstein.

"The deadly pathogen is carried by water and can affect vast areas in a very short time," he said, adding that presently no method has been found to help sea urchins.

Since there is no method to contain the infection among sea urchins, Bronstein urged the establishment of coral breeding populations in isolated cultivation systems as a precaution.