Sizeable colonies of a large stony coral species called Oculina patagonica, first recorded in Argentina in 1908, have been observed for the first time this year on jetties in Maltese harbours by researchers from the Marine Ecology Research Group of the University of Malta’s Department of Biology.

After a few decades when no living individuals of this species could be found, a living specimen was recorded in the Mediterranean in 1966 in Savona Harbour, Italy. Since then, the coral has been observed in several other places in the Mediterranean, including Spain, France, Algeria, Tunisia, Croatia, Greece, Turkey, Egypt, Lebanon and Israel.

Colonies of this yellow coral, which can reach more than a metre in diameter, are unlikely to have gone unnoticed if it were present in Maltese waters for a long time. This, together with the fact that it was discovered growing on artificial substrata in harbours, points to a recent introduction.

The coral seems to be acting invasively in the Mediterranean. However, its origin in the area remains enigmatic. No fossils of the species are known from the area, which indicates that it is not a native species and must have been introduced from somewhere else. At the same time, no living individuals are known from anywhere outside the Mediterranean and recent genetic analysis suggested it may have been present in this sea for much longer than previously thought.

Any unusual or new marine organisms found in Maltese waters may be reported to the Marine Ecology Research Group by contacting its leader, Prof. Patrick J. Schembri, at the University’s Department of Biology on 2340 2272 or by e-mail at patrick.j.schembri@um.edu.mt.