THE numbers of invasive toxic lionfish are rapidly increasing off the Cyprus coast, and while the fisheries department does not sound particularly worried, a Limassol marine expert has described it as a “disastrous marine invasion”.
In the Mediterranean, their invasion has been helped by a substantial deepening and widening of the Suez Canal which connects the Red Sea with the Mediterranean and was completed in 2015. Another factor is rising sea temperatures.
A lionfish bite can be painful, causing headaches, vomiting and breathlessness, but its toxin is only fatal if someone is allergic to it. There have been no reports of anyone being bitten in Cyprus so far.
“They expand at an alarming rate; this is a disastrous marine invasion,” Demetris Klitou from the Marine and Environmental Research Lab (MER) in Limassol said on Wednesday. “It has been shown in other countries over the years that the invasion of lionfish has adverse impacts.”
The fisheries department, however, is more sanguine.
“They are one of many invasive species,” said fisheries department official Nicolas Michaelides. “Since the Suez Canal was widened and deepened, many more have entered the area.”
“There is now a much bigger biodiversity, which is positive. We live in interesting times,” Michaelides commented.
The lionfish have been multiplying in the Eastern Mediterranean and are likely to do so in future. “They don’t have any natural enemies here,” Michaelides explained.
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 that deter predators make them extremely effective at colonising new territories.
Even sharks are reluctant to attack them which leaves the lionfish to consume much of the local species. This does not necessarily mean that all fish is depleted, as there are other fish finding their way through the canal. These invasive fish, which have had to survive in tougher conditions, may be able to fight the intruder.
“They come from areas with more biodiversity and they feed on many different foods. They are also more adaptable to climate,” the fisheries department official explained.
Yet so far, in Cyprus no measures have been taken to reduce their numbers. “We are monitoring their numbers,” Michaelides said. “Nobody knows what is going to happen yet and whether a decision will be taken to start a programme.”
According to the fisheries department, the effects on the ecosystem are not clear and the pros and cons need to be weighed.
In fact, he said, the presence of the lionfish could be good for diving tourism, as the fish have unusual looks.
But Klitou is concerned, citing the results of a recent study he had published in the journal Marine Biodiversity Records.
“Our study shows that within a year they have colonised the area. Invasions of lionfish in the US have shown that only an early response is efficient. If we don’t take action now that there are a few hundred it will be too late to control them,” he said.
“Divers and fishermen should be trained to spear them and need to be trained to that effect, instead of divers who don’t kill them because they deem them to be a tourist attraction,” he explained.
A solution which has been tried in other countries is to promote eating them. Contrary to popular belief, lionfish are not only edible, but extremely tasty. The toxin is present only in the venomous spines, so once this is removed it can be eaten like any other fish. As well, Michaelides said, the poison is a type of protein which is destroyed in the cooking process.
In places like Cuba, Colombia and the Bahamas, governments have encouraged their populations to start eating the fish to keep down numbers. Cuba now holds an annual fishing tournament for the species. Restaurants have begun serving its juicy white flesh, which is enjoyed as a delicacy in Japan, according to a report by broadcasting service Deutsche Welle.