By Annette Chrysostomou
As reactions this week to the recent invasion of lionfish in the Eastern Mediterranean sea show, it is often not clear what can and should be done about alien species which reach a country and stay there.
While there are many non-native species moving around the earth, few are thought to be invasive. By definition an invasive species has the ability to spread causing damage to the environment, the economy and the way we live.
The invasion of lionfish, which has a nasty bite, was widely reported in the media this week. But it is just one of several hundred Indo-Pacific marine species, flora and fauna, that have become established in the Eastern Mediterranean Basin following the widening and deepening of the Suez Canal which finished last year, according to a United Nations report on biological diversity. Yet there have been few reports of them causing extensive damage.
One relatively recent invader which certainly seems dangerous is the pufferfish which can kill people. The fisheries department has a programme to reduce their numbers.
“We buy the fish from the fishermen,” Nicolas Michaelides from the fisheries department explained, “partly to encourage them to catch them and partly to help pay for the damage they do to their nets.”
But experts question whether there is any point in such programmes.
“Many species such as the pufferfish already have an established population,” commented Demetris Klitou from the Marine and Environmental Research Lab (MER) in Limassol. “The stage where they can be controlled has passed.”
The fisheries department also questions whether the attempt at reducing the numbers by going after them with spears and nets has any results. The pufferfish programme has been running since 2010, and after monitoring it for six years the fishery department reports there is as yet insufficient evidence that the numbers have gone down.
It is even less clear what the lionfish will do to the local ecosystem and what should be done about them as they have only recently arrived in Cyprus waters.
The department monitors the rapid expansion of the fish and say the consequences are as yet unknown. They confirm it is consuming much of the local fish population, but add the situation is not that simple. Other fish are also entering the Mediterranean in big numbers mainly through the Suez Canal, and their interaction with the lionfish is as yet unknown. The invaders are tougher than the locals, having had to deal with different environments, and they are more adaptable to climate changes.
Klitou, citing the results of a recent study he published in the journal Marine Biodiversity Records does not agree; he calls the development “a disastrous marine invasion”, saying it is high time to control it.
Despite their ferocious appetite and their nasty bite, a number of positive impacts are evident, and more could emerge over time.
Lionfish is known to be a delicacy in eastern countries, just like the more dangerous pufferfish, and there is a possibility of either selling the fish to other countries or introducing it to the local cuisine, as once the venomous spine is removed, it can be eaten just like other fish.
It has also helped diving tourism in other countries, as the fish have an unusual appearance and tourists flock to see them.
Indeed, some experts such as veteran environmental journalist Fred Pearce suggest that trying to keep alien species out looks increasingly flawed. In his 2015 book The New Wild: Why Invasive Species will be Nature’s Salvation he argues that much of what has been thought of as harmful invasions has been misconstrued and/or exaggerated and instead novel dynamic ecosystems are constantly being created.
“We all like a simple story with good guys and bad guys,” he writes, “and aliens always make easy enemies.”
In fact, he suggests, the success of these aliens might be a sign of nature’s resilience in the face of the considerable damage humans have done to the planet.
“Understandable love of the local, the native and the familiar – of an imagined pristine environment before humans showed up – too often becomes fear and hatred of the foreign and unfamiliar.”
There are horror stories, he acknowledges.
It has happened before in Cyprus that a dangerous species established populations impossible to eradicate afterwards when the small but dangerous red palm weevil was introduced via the import of infested palms from Egypt.
The first four infested palm trees were found in a hotel in Limassol in 2006. By 2010, the insects had spread to all areas in Cyprus, and there is now evidence that they will slowly kill most palm trees in the country.
It is hard to think about rodent rats, palm tree eating weevils and deadly pufferfish in a positive way. But having researched the subject for years, Pearce comes to the conclusion that most introduced species either swiftly die out or settle down and they rarely eliminate native species.
This might be the case with the lionfish, and we may, as Michaelides believes, end up with a different, more diverse and more interesting Mediterranean Sea.
In any case, we will probably be left with no alternative way of thinking about the subject, as we humans are the ones who actively encourage invasions by facilitating creatures’ journeys in man-made canals, ships, planes and by other modes of transport. We also change the climate, forcing nature to react as best as it can.
As Pearce’s books concludes “the invasions may not always be convenient for us, but nature will rewild in its own way. This is the new wild.”