In recent years, non-native lionfish have become more and more common in parts of the Mediterranean, threatening the local ecosystem and posing harm to humans through their poisonous spines.
Marine biologist Professor Jason Hall-Spencer first saw lionfish off the coast of Cyprus in 2016. It’s just an individual, but the species-which lays about 2 million eggs a year and lacks natural enemies in new environments-quickly became popular. “In some places, I saw 40 in one dive,” Hall-Spencer of Plymouth University Say.
In response to the growing number of lionfish, Hall-Spencer and other researchers from the University of Plymouth and the Cyprus Marine and Environmental Research Laboratory worked with specially trained divers and citizen scientists to coordinate the removal event within six months And investigation. This collaboration is part of the ReLionMed project funded by the European Union.
“[Lionfish] Right in the shallow depths where you can swim-we see them at a depth of 1 or 2 meters-they will give you a very nasty sting because their fins are full of venom,” Hall- Spencer said.
Lead author Periklis Kleitou said that although there are records of lionfish in shallow waters, they mainly live in deeper waters and therefore pose a greater public health risk to divers. Research published in “Aquatic Protection”. “As they expand [their range], We hope they will not invade the coastal areas, where there are many tourists. “
But lionfish cause more problems than the threat of painful stinging. The invasion of this species in other parts of the world shows that carnivorous fish can quickly settle on coral reefs and reduce the biodiversity of the area, which is a problem for the ecology of coral reefs and local fishermen.
Native to the warm tropical waters of the Indo-Pacific Ocean, the first official discovery Europe It happened in 2012, and it happened in Cyprus in 2014. Ocean warming and the expansion of the Suez Canal played a role in the lionfish invasion from the Red Sea into the eastern Mediterranean. They are spreading rapidly, and some have reached Tunisia and Italy.
Now, research shows that removing these fish may help control their populations.
Hall-Spencer said that people found lionfish in the Marine Reserve (MPA), which was set up to protect the native creatures of the Mediterranean. “what [MPAs] What they are doing effectively is protecting these invasive species — they provide a safe haven — which is a worrying issue,” he said.
“Eradication is impossible,” the doctor said Louis Hadjioannou is a joint research biologist with the Cyprus Institute of Oceanography and Maritime Affairs and Enalia Physis Research Center. “We are talking about population control,” he said.
The team conducted five cleanups with specially trained volunteer divers, and they caught 35 to 119 lionfish every day in each of the three research marine reserves off the coast of Cyprus.
The study also used citizen science to monitor the number of lionfish in survey sites after migration. The combination of citizen science reports and fixed cross-sectional monitoring showed that the number of lionfish decreased after removal.
The lionfish resettled at different rates, and the researchers attributed this to the connectivity with neighboring coral reefs. One problem is that lionfish can be found 100 meters below the surface, which is far beyond the limit of recreational diving.
“This means that there is a lionfish reservoir in an unreachable area,” Hadjioannou said. These fish can reach areas that have just experienced migration and reproduce.
The lionfish monitoring in the study was carried out in a short period of time. More long-term research is needed to determine whether removal can be a long-term solution, allowing for better scheduling of events and helping to determine target locations for optimal results.
Researchers have found that a multifaceted approach is needed, including advocating for greater protection of large predatory fish that may feed on lionfish, and encouraging local fishermen to catch them.
In fact, tourists from Cyprus will soon see lionfish on the menu. It has appeared in fish markets and some restaurants. As the market grows, it is hoped that their value will increase. The project also cooperates with the market to promote the sale of jewelry made of lion fins.
“With climate change, lionfish is expected to invade parts of the western Mediterranean,” Kleitou said. Since this fish is already prevalent in other parts of the southeastern Mediterranean, “the long-term goal is to continue to transfer our knowledge to neighboring countries.”
Hall-Spencer explained that we still need to work hard to prevent further intrusions. He described the Suez Canal as a “severed artery” that “injected all these fish and other species, including viruses and bacteria, into the Mediterranean.”
“What really needs to happen is some kind of biosecurity control,” he added, and suggested using desalination plants that produce high-salt wastewater and put it into the Suez Canal. “I think this will require international coordination and possibly international funding to achieve this kind of biosecurity,” he said.
