Once found only in the Indian and Pacific oceans, before spreading in recent years to the Caribbean and Atlantic, lionfish have been found in the Mediterranean Sea for the first time in more than 20 years, scientists report.
Authors of a report published last week called for immediate monitoring and control of lionfish in the Mediterranean to be carried out to try to prevent an invasion of the creatures. The invasive species has wreaked havoc on coral reefs in the Caribbean.
Lionfish have not been seen in the Mediterranean since 1991, when a single lionfish was discovered. More than two decades later, two lionfish were found late last year off the village of Al Minic, in the northern part of Lebanon.
According to a report in Mediterranean Marine Science published on 3 June, the first was caught in October 2012 using a wire trap and photographed by fishermen before being discarded. The second was caught in December using a trammel net at 30 metres.
Both specimens were found to be of the genus Pterois miles. Lionfish of the closely related Pterois volitans is the kind more commonly found in the Caribbean.
Two more unconfirmed sightings of lionfish were made off Cyprus in February this year, the researchers reported.
“Considering that P. miles is a common fish in the Red Sea and the proximity of the Suez Canal to the recent sightings, the Suez Canal seems to be the most likely pathway for the introduction of the species into the Mediterranean Sea,” said report authors Michel Bariche and M. Torres of the American University of Beirut and Ernesto Azzurro of the Institute for Environmental Protection and Research in Italy.
Unlike in the Caribbean, where lionfish appear to have no natural predators, the scientists reported that one potential predator of lionfish already exists in the Mediterranean – the blue spotted cornetfish.
They said that in the northern Red Sea, a juvenile lionfish was discovered in the stomach of a cornetfish. In the past decade, blue spotted cornetfish have invaded the Mediterranean Sea and established large populations in the eastern part “and may act as a biological control of a future possible invasion”, the scientists reported.
Researchers said another possible lionfish predator could be the native Mediterranean grouper.
Grouper in the Caribbean have been seen eating injured and dead lionfish caught by divers, but as yet do not appear to be hunting lionfish.
Even though there have only been a tiny handful of sightings of lionfish in the Mediterranean Sea, the scientists said these recent findings may indicate the onset of an invasion.
Pointing to the lionfish eradication efforts in the Caribbean that include recreational divers capturing lionfish and commercial divers and fishermen targeting them as a source of food, the authors said that even with those ongoing initiatives, “when the lionfish has established a permanent population, its complete eradication seems to be unrealistic”.
They added: “Therefore, in the Mediterranean Sea, it will be extremely important to raise awareness and to implement monitoring efforts during the early stages of colonisation, when control measures could still be effective.”