Prides of poisonous lionfish invading the Mediterranean

28 Jun 2016

Climate change has plenty of losers, but let’s not forget the winners that are emerging. Poisonous lionfish (Pterois miles) have been loving the Mediterranean’s new, warmer environment this past year.

Following news of an octopocalypse, as cephalopods profit from warming waters and enjoy dramatic population booms, news has now emerged of an alien invasion in the Mediterranean Sea.

The venomous lionfish is now a major threat in the Med, with divers and fishermen noticing a spike in sightings in the past year.

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The predators have seemingly colonised Cyrpus, perhaps instigating a pan-Atlantic Ocean invasion following the widening and deepening of the Suez Canal.

This is all documented in a paper in Marine Biodiversity Records, which notes the proliferation of the species’ mating – spawning every four days – and ease with which they travel.

“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 the western Atlantic,” said Demetris Kletou, who headed the paper.

“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.”


The fear is their relentless reproduction, ease of travel and venomous deterrents to other predators will mean they soon dominate the Mediterranean seabed, destroying reefs and killing off rival, or preyed-upon, species.

Lionfish are a bit of a nightmare. Each female produces around two million eggs a year, with population booms of the hungry fish in the US leading to reports of obesity in the species, as well as cannibalism.

Professor Jason Hall-Spencer, who also worked on the report, said he hoped this new information will help people determine mitigation plans, such as lionfish removal programmes.

These have worked in the Caribbean, he says, while suggesting the restoration of dusky groupers that prey on lionfish is another option.

“Given that the Suez Canal has recently been widened and deepened, measures will need to be put in place to help prevent further invasion.”

Lionfish images (1 and 2) via Shutterstock

Gordon Hunt was a journalist with Silicon Republic