Monitoring Surfactants Pollution Potentially Related to Plastics in the World Gyres Using Radar Remote Sensing

Plastics within the ocean have been found to be colonised by microorganisms that, as a by-product of their metabolism, produce surfactants. Short capillary waves on the sea surface can get dampened due to the increased surface elasticity of these surfactants. Radar satellites are sensitive to surface roughness and can therefore detect the dampening of these waves. This research investigates areas inside the Atlantic, Pacific and Indian Ocean gyres using ESA Sentinel-1 and DLR TerraSAR-X data. We found out that we can observe several surfactant instances in the gyres and these are not correlated to medium or high level of chlorophyll. We can exclude that they have origin in biogenic slicks. Among other possible unknown origins, we hypothesise that these surfactants are produced from plastic concentrations within the ocean.