The silver-cheeked pufferfish, scientifically known as Lagocephalus sceleratus, has rapidly proliferated across the Mediterranean Sea, alarming fishermen and tourism officials. This species, native to the Indian and Pacific oceans, was first recorded in the Mediterranean in 2003, believed to have entered through the Suez Canal in a phenomenon termed Lessepsian migration. Its presence now extends from Spain and the French Riviera to Turkey and the Greek islands.
The fish poses a significant danger due to its potent neurotoxin, tetrodotoxin, found in its liver. This poison is lethal in minute quantities, blocking nerve signals and leading to paralysis, respiratory failure, and potentially cardiac arrest. There is no antidote, with the only hope for survival being artificial respiration until the kidneys can filter out the toxin over several days. Marine biologists advise against touching the fish without gloves, as even skin contact can cause illness and respiratory issues.
Beyond its toxicity, the pufferfish possesses formidable, razor-sharp teeth capable of slicing through flesh and bone. The Red Cross recommends immediate wound washing and elevation for any attacks, along with tetanus shots and stitches for deep injuries. While AI-generated videos depicting the fish biting through objects are inaccurate, their aggressive feeding habits are well-documented. Videos show the fish engaging in cannibalism, a behavior increasingly observed, possibly due to their rapidly growing numbers and availability of easy food sources.
Economic Impact on Fisheries
The silver-cheeked pufferfish has become a significant economic threat to Mediterranean fishing communities. Their voracious appetite extends to fishing nets, where their powerful jaws and fused teeth can cut through lines and mesh. This depredation not only results in lost catches but also leads to substantial costs for net repair. Some fishermen in Crete report losing up to 30 percent of their annual income, with losses per vessel reaching as high as 20,000 euros annually. This makes it difficult for fishermen to make a living, with some spending more time repairing nets than fishing.
Efforts to mitigate the invasion have been initiated by some governments. The Greek government offers a bounty of up to 5.33 euros per kilogram for caught pufferfish, and Turkey has implemented a similar scheme, though fishermen report inconsistent payments. However, these payments are described as a last-ditch effort to prevent the collapse of fishing villages, as the fish's population is expanding too rapidly for these measures to have a significant impact.
Ecological and Tourism Concerns
The pufferfish has few natural predators in the Mediterranean, and its population growth is exacerbated by overfishing and pollution, which have depleted populations of larger, indigenous fish. The fish are also growing larger than their native counterparts, with specimens up to 4 feet long and weighing 20 pounds being reported, possibly due to the colder Mediterranean waters requiring less oxygen for energy expenditure.
The Hellenic Centre for Marine Research in Greece has issued warnings to holidaymakers, urging caution when swimming or fishing. The threat to the tourism industry is considerable. In response to the danger, the Greek island of Evia has installed a miles-long floating barrier anchored to the seabed. This barrier is constructed from a rigid polymer designed to withstand the pufferfish's bite and also deters jellyfish, offering a measure of protection to swimmers.
Disposal of caught pufferfish presents another challenge. They are too toxic to be consumed and cannot be safely discarded in landfills, as scavenging animals have been known to eat them, leading to animal deaths. The current recommended disposal method involves freezing the fish, followed by periodic incineration of large batches and burial of the ashes. Over 100 tons of pufferfish have already been caught and destroyed, but this is considered unlikely to make a substantial difference to the overall population. 
