The Turkish Marine Research Foundation claims that the Mediterranean Sea, with which Türkiye boasts a long coastline, is witnessing "a biological invasion" by non-indigenous species.

Istanbul University's Faculty of Aquatic Sciences member and Turkish Marine Research Foundation (TÜDAV) President Bayram Öztürk stated that the non-indigenous species that threaten the fishery and ecosystem in the Marmara Sea are rapidly increasing.

More than 10% of the marine diversity is now foreign with 100 species in the Marmara Sea and 60 in the Black Sea. Some of these species are poisonous, while some are caustic. There are not only non-indigenous but also invasive varieties that need to be controlled.

From the spread of the poisonous and invasive pufferfish on the western coast of Türkiye to the sighting of lionfish, many non-indigenous species have sparked concern. Pufferfish, also known as blowfish, are a predator that contains tetrodotoxin, a lethal substance for humans, up to 1,200 times more poisonous than cyanide. After the poisonous lionfish migrated to the Mediterranean through the Suez Canal, it has become especially common in the northeastern Mediterranean region. The first one in Türkiye was observed in 2014 and later spread along the Turkish coast from the southern province of Mersin to the bay of Antalya and all the way up to Izmir.

"For ecosystem, biodiversity, health and fisheries, an early warning system should be established along with monitoring. Fishing, tourism and human activity should be banned in certain regions," Öztürk said.

Öztürk said that invasive species cause bio-security issues and that there are approximately 1,700 foreign species in the Mediterranean and more than 100 in the ​​Marmara Sea. He stated that foreign fish species are now also sold in markets, which also pose a threat to public health. For example, one pufferfish is enough to kill 30 adult humans, and there is no known antidote so far. Interestingly, the meat of some pufferfish is considered a delicacy. Referred to as "Fugu" in Japan, it is extremely expensive and only prepared by trained, licensed chefs who know that one bad cut means almost certain death for a customer. In fact, many similar deaths occur annually.

Öztürk stated: "Since the opening of the Suez Canal, over 1,000 foreign species have entered the Mediterranean. The Suez Canal is the gateway for (non-indigenous) species into the Mediterranean. More than 350 species are already spreading across the sea. These invading species, ranging from fish to shrimp and jellyfish, have already affected the biodiversity here. For instance, rhopilema nomadica, a jellyfish originating from the Red Sea, is now prevalent in the Eastern Mediterranean region. Its damage includes an impact on fishing as it damages fishing nets.

Referring to his book, he said to prevent this biological threat, strong preventive measures are needed; and added that no matter how much the ministry assists, the damage they cause to the ecosystem is not assessed properly.

"An early warning system should be established along with monitoring. What will fishermen do in the face of new arrivals? What will people do? What will those who want to swim do? What will those who want to sail do? These must be planned. We need to keep an eye on the Marmara because alien species are increasing. The Marmara is our living room, and we polluted it. Human activity must be restricted in certain regions," he concluded.