Dolphins and whales, indicator species for the health of the ecosystem, are facing immense pressure due to threats such as overfishing and plastic pollution, said Arda Tonay, a faculty member of Istanbul University's Faculty of Aquatic Sciences, Department of Marine and Inland Water Resources Management and vice president of the Turkish Marine Research Foundation (TÜDAV).
Regarding the variety of marine species, Tonay said: "There are eight cetaceous constantly found in the seas of Türkiye, including the long whale, puffer, beaked, grampus, bottlenose dolphin, striped dolphin and harbor porpoises. There are also minke whales, false killer whales and humpback dolphins in Turkish seas."
Mentioning that there are three species in the straits of Istanbul, the Dardanelles and the Marmara Sea, Tonay said that the number of dolphin and whale species in the basin was not known with today's clarity until three years ago.
"Thanks to the Agreement on the Conservation of Setase Species Living in the Black Sea, the Mediterranean and the Contiguous Atlantic Region (ACCOBAMS) Survey Initiative (ASI) and eight aircraft, six ships and 100 scientists from 26 countries in the Mediterranean in 2018 and in the Black Sea in 2019, we counted whales and dolphins. The study shows that the largest whale in the Mediterranean and the second largest in the world, the long whale, has a 1,700 adult population here and this species is endangered. However, the population of beaked whales in the Mediterranean is about 6,000 and is decreasing. The smallest species of the Black Sea basin, the harbor porpoise, with a maximum length of 1.5 meters, are estimated to number between 100,000-250,000," Tony explained.
Pointing out the number of dead harbor porpoises caught in the Black Sea, Tonay said, "Only in the Western Black Sea coast of Türkiye, about 2,000 harbor porpoises die each year."
Stating that whales and dolphins, which represent the top of the food chain in the seas, are indicator species for the health of the ecosystem, "If there is a whale and dolphin somewhere, the ecosystem is at an acceptable level," Tonay said.
"Whales are animals that can dive deep, up to 2,000-3,000 meters, and feed on deep-dwelling squid. When they defecate, they come to the surface to breathe. They use phytoplankton and photosynthesis. Fifty percent of the air we breathe comes from phytoplankton. The system is one of the largest and pulling anything out of it will cause the system to crash," he added.
Emphasizing that fishing activities top the pressure factors that threaten the species, Tonay drew attention to the fact that small species that are not aware of the fishing nets are caught in the nets by chance. In addition to the threat of overfishing, pollution weakens the immune system of animals, whales and dolphins.
"Studies, such as seismic research in the seas, can also be dangerous for deep-diving species," Tonay pointed out.
Explaining that plastic waste is another pressure factor, Tonay said: "There are animals that have a lot of plastic waste in their stomach. This can cause their death or affect their diving. Last year, we removed plastic buckets and bags from the stomach of a puffer whale."
Pointing out that data regarding the fish population in the seas is important in terms of creating protected areas, Tonay stated, "There is not even a single protected area in the Black Sea."
ACCOBAMS, which Türkiye signed in 2018, is the most important protection agreement for marine mammals. During the celebration of the 25th anniversary of ACCOBAMS's founding, a book was released about the seas by the Oceanographic Museum of Monaco with the participation of Prince Albert II. The book is free and can be downloaded from the ACCOBAMS website for anyone who would like to learn about these unique animals.
