Evaluating the Role of Deep Sea Discharge Systems and Anthropogenic Pressure in Mucilage Formation: A Case Study of the Sea of Marmara

The Sea of Marmara has undergone significant ecological degradation over the past decades, primarily driven by intensive industrialization and rapid demographic shifts. 2021 mucilage outbreak served as a critical indicator of the ecosystem’s threshold being surpassed. This study investigates the anthropogenic pressures within the Sea of Marmara hydrographic basin between 2007 and 2021, linking these stresses to the mechanisms of mucilage formation by highlighting their role as primary chemical precursors By analyzing a 14-year dataset across seven coastal provinces, the research evaluates population growth, wastewater generation potential, and treatment infrastructure. Findings indicate a 25.3% population increase, coupled with a disproportionate 55% surge in wastewater potential. A detailed discussion of 40 deep-sea discharge systems reveals a per capita wastewater generation of 290 L/day which is surpassing existing literature benchmarks. Notably, in Istanbul, the wastewater generation rate rose by 23%, outpacing its 26.5% population growth. The study further provides a spatial analysis of critical hotspots, including the Gulfs of Bandırma, Gemlik, and Erdek, alongside the Ergene Basin and the Turkish Straits System. By quantifying localized wastewater loads, this paper proposes strategic management frameworks and urgent infrastructural precautions necessary to restore and sustain the water quality of this unique inland sea.