Turkey has vowed action to fight the thick mass of marine mucilage, also dubbed "sea snot".

Boats are seen near the Caddebostan shore, on the Asian side of Istanbul, June 7, 2021.

President Recep Tayyip Erdoğan promised Saturday to rescue the Marmara Sea from an outbreak of "sea snot" that is alarming marine biologists and environmentalists.

Seagulls roost on rocks by the sea covered with a plague of 'sea snot', June 6, 2021.

Much of the mucilage seen on the surface of the Marmara Sea is due to an excessive increase of phytoplankton microscopic algae, Istanbul, Turkey, June 7, 2021.

In the Marmara Sea, these single-celled microorganisms also multiply by taking advantage of the marine pollution caused by domestic and factory wastes and the changing water temperature level due to global climate change.

A man steers a small boat out of sea snot in the port of Burgaz Island, June 5, 2021.

Istanbul residents enjoy their first Saturday without COVID-19 curfews in months and many took the opportunity to visit the city's Princes' Islands in the Sea of Marmara, which since May has been experiencing a phytoplankton boom known as sea snot or sea mucilage due to excess pollution in the marine ecosystem.

An aerial photo of the sea at the Caddebostan shore, in Asian side of Istanbul, with a huge mass of marine mucilage, June 7, 2021.

A thick layer of "sea snot", consisting of a wide variety of microorganisms, covering the sea near the coast in the Bostanci harbor in Istanbul, Turkey May 31, 2021.

Drone footage shows 'sea snot', spreading through the Sea of Marmara and posing a threat to marine life and the fishing industry, June 7, 2021.

An aerial photo of Pendik port in Asian side of Istanbul, June 4, 2021.

A boat makes its way through the sea snot in Istanbul, June 7, 2021.

Streaks of mucilage trails after a boat leaving a small harbor on the coast of Istanbul, June 5, 2021.

A wide shot of the sea at the Caddebostan shore, in Asian side of Istanbul, June 7, 2021.

Children play on sea at the Caddebostan shore, June 7, 2021.

An aerial photo of the sea at the Caddebostan shore with a boat just crossing the edge of the mucilage, June 7, 2021.

An aerial photo of a small harbor at the Caddebostan shore, June 7, 2021.

The photo shows mucilage covering the surface of the Marmara Sea, coast of Istanbul, Turkey on June 1, 2021.

A seagull flies over a plague of 'sea snot', June 6, 2021.

A cleaning vessel works at Istanbul's shore to remove the mucilage June 7, 2021.