The Sea of Marmara, ringed by 25 million people, is running out of oxygen. In 2021 a thick gelatinous layer of "sea snot" spread across its surface, an algal secretion that is harmless to humans but suffocates fish and other marine life. Necla Köseoğlu, one of the last small-scale fishers working out of Rumelikavağı and one of the few women in the trade, describes catches that no longer support a living. Marine biologist Hasan Örek and other scientists explain how decades of overfishing, shipping traffic, and untreated waste have pushed the ecosystem toward collapse. Istanbul environmental engineers Ayşen Erdinçler and Ilker Aslan detail the city's response, stricter fines and controls on shipping pollution, and why they call it insufficient against the millions of cubic meters of raw sewage and industrial discharge entering the sea daily. The film lays out the blunt math behind the crisis: outdated treatment plants that need modernizing and a government without the funds to do it, leaving a sea that once fed a region now fighting to keep breathing.