Lionfish are invading the Mediterranean as a result of rising sea temperatures, posing serious ecological damage to native species, scientists have warned. The poisonous predators managed to colonise the entire south eastern coast of Cyprus in just one year, while experts believe the widening of the Suez Canal will exacerbate the problem in the near future.
The lionfish species Pterois miles, also known as the Devil firefish, is native to the Indian Ocean. However, it has been increasingly reported in the eastern Mediterranean, on the east coast of the US and the Caribbean Sea, where it is considered an invasive species.
Scientists from Cyprus and the UK have now published a report looking at their prevalence in the Mediterranean. Published in Marine Biodiversity Records, they collected information about encounters with lionfish from fishermen and divers, while gathering photographic and video evidence of sightings.
Lionfish are carnivores feeding on a variety of fish and crustaceans. They produce around two million eggs every year, spawning every four days. The offspring is able to travel large distances by riding on ocean currents for about a month before settling down. Their reproductive rates, their early maturation and their venomous spines makes them extremely effective at colonising new territories. Invasions often result in a reduction in biodiversity.
Findings showed they had taken a foothold in Cyprus and that a further invasion from the Atlantic Ocean could be on the way because of the widening and deepening of the Suez Canal.
"Until now, few sightings of the alien lionfish Pterois miles have been reported in the Mediterranean and it was questionable whether the species could invade this region like it has in the western Atlantic," said Demetris Kletou, one of the authors of the report.
"But we've found that lionfish have recently increased in abundance, and within a year have colonised almost the entire south eastern coast of Cyprus, assisted by sea surface warming."
Report co-author, Jason Hall Spencer, added: "Groups of lionfish exhibiting mating behaviour have been noted for the first time in the Mediterranean. By publishing this information, we can help stakeholders plan mitigating action, such as offering incentives for divers and fishermen to run lionfish removal programmes, which have worked well at shallow depths in the Caribbean, and restoring populations of potential predators, such as the dusky grouper.
"Given that the Suez Canal has recently been widened and deepened, measures will need to be put in place to help prevent further invasion."