Madrid.- A lethal disease that has reached the Indian Ocean is endangering the survival of sea urchins in the Red Sea, the consequences of which could be disastrous for coral reefs. A new study has identified the single-celled organism responsible for that epidemic.
The disease, which mainly affects the Diadema setosum and Echionthix species, is caused by “a scuticociliate parasite very similar to Philaster apodigitiformis,” according to a study led by Tel Aviv University.
Philaster apodigitiformis was already identified last year as the cause of death of hundreds of Diadema urchins in a large area of the Caribbean Sea.
Diadema urchins, black and with large spines, are considered the ‘gardeners’ of coral reefs, as they feed on algae that compete with them for sunlight.
The disappearance or strong mortality among this species can seriously affect the delicate balance of reefs around the world, the university highlighted in a statement.
The epidemic, discovered last year, “has essentially wiped out” urchins of the two most abundant and ecologically significant species in the coral reefs of the Gulf of Eilat (Israel), from where it spread to the entire Red Sea to reach the Indian Ocean.
Deadly sea urchin epidemic
What at first seemed like a “serious but local” epidemic has spread rapidly throughout the region and now threatens to become a global pandemic, according to researchers.
The lead author of the study, Omri Bronstein, from Tel Aviv University, and his team were the first to identify mass mortality of Diadema urchins in the Red Sea and also discovered that the epidemic was lethal for other closely related urchins of the genus Echinothrix. .
This disease causes rapid death. In just two days, a healthy sea urchin becomes a skeleton without tissues or spines and unable to defend itself from predators.
Bronstein considered that “this is a growing ecological crisis, which threatens the stability of coral reefs on an unprecedented scale” and drew attention to the fact that the pathogen that causes it is transported by water and can affect vast areas in very little time.
Even urchins raised in seawater systems at the Eilat Interuniversity Institute of Marine Sciences or the Underwater Observatory became infected and died, after the pathogen entered through the seawater recirculation system.
Until recently, only one species of hedgehog was known to be affected by this pathogen, the Caribbean, but today it is known that there are others susceptible to the disease, “all of them belonging to the same family of the most important herbivorous sea urchins in the reefs.” of coral.”
The study also shows that the epidemic spreads along human transport routes in the Red Sea.
Currently there is no way to help infected animals or vaccinate them against the disease, however, the researcher considered that breeding populations of threatened species must be quickly established in farming systems disconnected from the sea, in order to be able to reintroduce them in the future in The natural environment. EFEverde
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