Jellyfish invade Bosporus, overfishing blamed

THE CHANGING ecosystem due to overfishing in the Bosporus in Istanbul caused the recent invasion of jellyfish, experts said yesterday.

Speaking to Demirören News Agency (DHA), Melek İşinibilir Okyar, an academic from Istanbul University, said that the number of some fish species which feed with jellyfish has decreased due to overfishing.

“For example, there is a very little number of mackerel fish left in the Marmara Sea, which feeds on jellyfish, due to overfishing. Or sprat fish, which also feeds on jellyfish. When you remove these species out of the ecosystem, the entire ecology evolves for the benefit of the jellyfish. Because there is no living creature in Bosporus to compete on it for survival. That’s why their number started to increase,” she said.

Okyar said that the jellyfish invasion is not a recent development or something that was triggered by the plastic problem, but a result of decades-long of wrong practices.

In Istanbul, specifically, the coasts of Arnavutköy, Ortaköy and Bebek neighborhoods turned white with an excessive number of jellyfish. The density of the species is also visible from the air. The fishermen are having trouble with the abundance of jellyfish, saying that it is not possible to fish. The residents of these neighborhoods also complain about visual pollution.

Okyar underlined that all institutions should come together and show joint efforts to find a permanent solution to the issue.

“Local governments, ministries, universities need to work together. There could not be a resolution developed by a single institution. We will come together and present our research results. Then, we need to create a road-map by raising awareness of both fishermen and people living around these areas. We can develop such rescue program for the entire Marmara Sea,” the academic said.

Mehmet Sarıyıldız, who has been fishing in the Bosporus for years, also grumbles about the extreme number of jellyfish. “This is probably the result of massive pollution. This year, the number of jellyfish is too much compared to other years. And it affected us,” he told DHA.

Many other fishermen also complained about jellyfish invasion.

Experts previously issued similar warnings regarding the rise in the number of jellyfish in the Turkish seas.