The seas of Turkey are experiencing an onslaught of invasive jellyfish.

The country’s difficulties with enormous swarms of the unsightly stingers pose a threat to its real prospects of leapfrogging France to become Europe’s second most popular tourist destination after Spain, in tandem with unbearable summer temperatures increasingly besetting Mediterranean resorts as part of climate change.

Rising water temperatures caused by the climate crisis, as well as pollution, create a favourable environment for jellyfish proliferation. Jellyfish populations along Turkey’s coastline have surged in recent years, particularly in the Marmara and Mediterranean Seas, Hurriyet reported on February 27.

Swimmers and beachgoers are told not to touch jellyfish as they are poisonous and can pack a nasty sting.

Turkey’s National Jellyfish & Gelatinous Organisms Watch Programme lately advised “sea lovers and marine enthusiasts” that in recent years there has been an “increase in the jellyfish blooms in the Mediterranean and Black Sea due to the changes in climate and food chains. Furthermore, the new alien jellyfishes, like ‘Lessepsian species’ that entered our seas via the Suez Canal cause current and important problems in the Eastern Mediterranean Basin.

“These jellyfish and gelatinous organisms clog fishing nets and damage our fisheries. On the other hand, some venomous species may cause nuisance to bathers and especially may become a real health hazard for babies and elderly individuals. So, this has a negative impact on tourism. It is known that thousands of people both in Europe and in our country have been hospitalised due to jellyfish stings in recent years.”

Turkish daily Hurriyet talked to an academic, Melek Isinibilir Okyar, who is leading a project investigating the reasons behind the jellyfish surge. She pointed out that jellyfish proliferation is often a precursor to the formation of mucilage in the sea, a dilemma those looking to protect the environment of the Marmara Sea have wrestled with in recent years in Turkey’s infamous battle against a “sea snot” crisis.

"There's a mucilage risk with warmer temperatures in winter months. Jellyfish also play a catalytic role in mucilage formation. When jellyfish multiply and die, they begin to disintegrate, leading to decreased oxygen levels and the accumulation of dissolved organic matter,” Okyar said.

“When temperature accelerates this process, mucilage forms in the environment. If there is organic matter to stick to in that environment, it starts to accumulate and eventually turns into masses,” she added.

The southern city of Mersin, a tourist destination on the Mediterranean coast, is one location that has seen its beaches inundated with jellyfish, alarming locals and tourists.