A submerged cliff wall invaded by O. patagonica coral. (Photo: CSIC)
Exotic coral species invades Almería natural ecosystem
Thursday, August 23, 2012, 02:30 (GMT + 9)
A team of researchers from the Higher Scientific Research Council (CSIC) found a natural ecosystem invaded by an exotic species of coral -- Oculina patagonica -- on a cliff of Almería.
The invading coral covers 55 per cent of the studied substrate, an amount never described before, states the study published in the latest issue of the journal Coral Reefs.
The experts assume that the coral species found is native to the southwest Atlantic.
This coral has caused a phase shift in the most superficial infralittoral community of Torre de Pirulico, in Mojácar, reported CSIC.
This species was first found in the Mediterranean Sea in 1966, but it has not stopped spreading and it is very abundant on shallow rocky bottom of the coast of Spain.
CSIC scientists have detailed that it covers between 10 per cent and 15 per cent of the shallow bedrock of the marine reserve of Cabo de Palos and Hormigas Islands, in Murcia.
According to Eduard Serrano, a researcher at the Centre for Advanced Studies of Blanes, "this species has already been described as the majority in some artificial habitats such as dikes of ports or breakwaters ports on the Spanish coast."
"But so far it has never been observed dominating better preserved natural habitats such as the cliff of Torre de Pirulico, where we have carried out the study,” he added.
After assessing the abundance of coral O. patagonica, the researchers determined that its average density is 24 colonies per square metre covering 55 per cent of the bedrock.
Coral colonies are up to 70 centimetres in diameter and many small colonies of less than one centimetre in diameter were also found, "which indicates that the population is effectively reproducing," warned Serrano.
Meanwhile, Rafel Coma, CSIC researcher at the Centre for Advanced Studies of Blanes, said the absence of sea urchins they have observed could indicate that "the erosion of the wall which causes the abrasion of the sand when there are waves is main reason why the O. patagonica has free space to colonize the ecosystem."
Researcher Marta Ribes of the Institute of Marine Sciences in Barcelona, states that sea warming seems to be favouring the expansion of O. patagonica.
"In temperate coastal ecosystems, algae are important primary producers and if this change in the dominant trophic level spread, it could affect the ecosystem functioning," the scientist warned.
By Analia Murias