The highest concentration of microplastics along the Bulgarian Black Sea coast is found in the Bay of Sozopol, according to a study by the Laboratory of Marine Ecology in Sozopol published in the international journal Marine Pollution Bulletin. Fibers were the most common type, comprising 72.3% of the microplastics on the shore and 91.7% on the seabed. Additionally, 44% of the particles on the shore and 54% of those on the seabed were red or blue.

 Concentrations in non-urbanized or sparsely urbanized areas were similar to those found in other studies from the Black Sea and other European seas. Major sources of pollution include microplastics carried from land via wastewater and stormwater runoff as well as degradation of plastic objects that have entered the sea from household waste, tourism, fishing and aquaculture, the publication reads.