An aerial photo of the sea at the Bostanci shore, in Asian side of Istanbul, Monday, June 7, 2021, with a huge mass of marine mucilage, a thick, slimy substance made up of compounds released by marine organisms, in Turkey's Marmara Sea. Mayoral workers and experts started Tuesday to clean the Marmara Sea from an outbreak of "sea snot" that is alarming marine biologists and environmentalists.(AP Photo)