Abstract: Mucilage in Marmara Sea and surrounding regions could reach excessive amounts in certain sessions. This could be a serious threat to the sea life and environmental health. Especially when mucilage with fibrillary structures cover the sea ground, it prevents the physiological functions of the sea life that lives in deep waters. First time with this project, we propose to characterize the mucilage structures that were collected from the base of Marmara Sea or produced from green algas in our lab by using Mueller Matrices Polarimetry and Raman Spectroscopy (SERS). The structural analysis will be conducted at low temperature ranges. That will also help us to have better understanding of structure-temperature correlations. Structural analysis will be further help to have better understanding of the cause for mucilage accumulations at certain sessions. We suggest to use eco-friendly extraction systems to extract polysaccharides from deep sea mucilage with high productivity. We are planning to conduct preliminary research to produce bioplastics by using the extracted polysaccharide to replace petrochemical plastics that also trigger mucilage formation by causing vast pollution in seas. Since 2021, single-use petrochemical plastics started to have certain restrictions in European Union due to their hazardous effect on environment. In order to replace them, there are extensive research efforts are going on and new application fields are in search for them.  However, when synthetic biodegradable plastics degrades, they release microplastics into sea that are consumed by fishes and through consuming sea products they reach to humans. They still pose a threat for human health and environment. This is the reason that there should be new alternatives that were completely dissolved in nature. Polysaccharides from mucilage will be decomposed completely in nature without any side products. Therefore, in this project, we suggest a solution to overcome vast accumulation of plastics in oceans. For this reason, we suggest to use chemical (pH, genipin, citric acid and boron components) and enzymatic crosslinkers to obtain bioplastics. They have almost none or very less toxic effect. If our preliminary results are successful, we are planning to continue our research with combining different natural waste materials with polysaccharides to obtain biocomposite plastics for multiple end uses and apply more specific research projects. In this way, we are aiming to decrease human originated pressure on sea microalga and other sea creatures. This might be an alternative solution *against one of the triggering effect on mucilage formations.