Jun 28, 2016

Invasive lionfish threatens the Mediterranean Sea

Aidan Quigley
The Christian Science Monitor
Photo: Christian Science Monitor
Photo: Christian Science Monitor

An invasive lionfish species found in the Mediterranean Sea could threaten the region's ecology if not addressed immediately, scientists say.  

Researchers from Plymouth University in Britain found that the venomous predators had colonized the coast of Cyprus, prompted by rising sea temperatures and the widening and deepening of the Suez Canal.

[Jason Hall-Spencer, a professor of marine biology at the University of Plymouth] says the Mediterranean was previously believed to have been too cold for the species to survive. But rising sea temperatures caused by manmade climate change have made the sea livable for the lionfish, he says. The deepening and widening of the Suez Canal has also played a role, as previously the canal had high salt areas that stopped the transport of species, he says. 

"With more flushing of water going through, it's more conducive to the spread of invasive species," he says.

An earlier lionfish invasion had a major effect on the Caribbean, which is heightening concerns about the Mediterranean. The carnivorous lionfish eat the small native herbivorous fish that keep algae and seaweed levels under control. Hall-Spencer says that in the Caribbean, lionfish devastated the population of herbivorous fish, which in turn led to unprecedented growth of seaweed, killing the coral reefs. 

The lionfish population boom in the Caribbean coincided with a 65 percent decline in native fish populations over the course of two years, research shows.[1]

They had no natural predators in the Caribbean – nor do they in the Mediterranean, says Hall-Spencer