Mucilage Event in the Sea of Marmara

Today's post will be about a hot topic. Some abnormalities were observed on the Sea of Marmara, more specifically a slimy substance that was resembling saliva was floating on the surface of the sea. This substance is called Mucilage, it was most likely formed because of industrial waste, insufficient treatment levels, and overfishing. It is affecting the ecosystems in both under the sea surface and above it negatively. This topic was discussed briefly in my lectures, when I got more curious started searching about this, I found a TÜBİTAK research paper about the exact same event I was pretty shocked to find out the same thing happened 10 years ago. 

Eskihisar, Gebze 23 May 2021. Photo: Ersin Duman

   

October 2007, İzmit Bay

    Left: October 2007, Erdek Bey. Right: January 2008, Erdek Bey Underwater 

To understand how and why it is formed, a detailed scientific search must be made. It is made up of organic material; a carbohydrate-protein mixture. Although there are many factors that trigger the formation of mucilage, the main reason is the increase in the accumulation of organic matter in the environment by human-induced ways. The mucilage formed in our seas is thought to originate from complex organic substances such as carbohydrates found in the cell contents of phytoplankton (diatom and dinophlogellate species).

Müsilaj oluşumunda etkili olduğu düşünülen bazı fitoplankton türleri (a:Skelotonema costatum, b:Prorocentrum micans, c:Gonyaulax fragilis.) 

In summary, the mucilage phenomenon is the rapid increase in the concentrations of polysaccharide structures and hydrocarbons in sea water, which occur due to the death of certain overgrowing phytoplankton and/or bacterial species, their rapid decomposition and failure to settle to the bottom. This slimy structure covers the bodies of many fish and invertebrates (corals, sea anemones, sponges, mussels, crabs, etc.) and causes clogging of structures such as gills and holes, which they use for the continuation of their metabolic activities such as respiration, feeding and excretion. 

Due to climate change, surface water temperature is increasing every year. This affects the underwater oxygen level. Factors such as climate change, increasing human-induced pollution, excessive and unplanned fishing, unplanned coastal structuring, and increasing marine traffic cause both serious wear of the ecosystem and great economic losses.

Sources:

• https://www.bbc.com/turkce/haberler-turkiye-57293708
• https://sarkac.org/2021/05/deniz-salyasi-nedir/#
• ‌Tüfekçi V., Balkıs N., Polar Beken Ç., Ediger D., Mantıkçı M. (2010); Phytoplankton composition and environmental conditions of a mucilage event in the Sea of Marmara. https://doi.org/10.3906/biy-0812-1
• Integrated Coastal Zone Management Lecture Notes, Aslı Numanoğlu Genç