Mucilage Problem in the Sea of Marmara
The Role of Phytoplankton in the Formation of Mucilage Observed in The Sea of Marmara from Past to Present
Neslihan Balkıs Özdelice, Turgay Durmuş, Muharrem BalcıEutrophication in coastal areas as a result of pollution from terrestrial input load can cause serious damage to marine ecosystems and the death of fish and benthic organisms through harmful algal blooms (HABs) such as mucilage. Phytoplankton form the first link of the food web in aquatic ecosystems through the synthesis of organic matter and have great importance in determining environmental changes due to being the primary producers with an essential place in marine productivity. Mucilage formation is observed through the aggregation of organic materials produced by phytoplankton in coastal areas, both in the water column and on the sea surface, and is another marine HAB phenomenon that occurs from pollution. The mucilage formation that was first seen in the Sea of Marmara in 2007–2008 reappeared in 2021 more intensely and longer lasting. While haptophytes, diatoms, and dinoflagellates in mucilage formations seen in these processes have been reported to show regional and temporal differences, they are the dominant phytoplankton groups in the mucilage mass. If the frequency and persistence of HAB events observed in the Sea of Marmara continue to increase, Türkiye's economy will suffer greatly due to the adverse effects to water quality, marine biodiversity, and the food chain. The relevant sources have predicted that the temperate Mediterranean climate will enter a tropicalization process with the increase in sea water temperatures caused by global climate change and that the Black Sea will enter a Mediterraneanization process through the immigrant influx of various species from the Mediterranean to the Black Sea. Significant changes in phytoplankton species composition and abundance in these changing environmental and pollution conditions will bring harmful algae growth and play an important role in its geographical spread. HAB formations in the coastal waters of Türkiye have emerged as a critical problem in conditions where the temperate Mediterranean climate is tropicalizing and the Black Sea is Mediterraneanizing.