Microplastics abundance in river runoff and coastal waters of the Russian part of NOWPAP area

The land-based sources of plastic contamination of the marine environment require thorough consideration. It is widely known that basic sources of plastic entering the sea are improperly managed landfills, unauthorized dumping sites in the river basins and in the coastal areas, sewage and stormwater, and rivers. It is possible to discuss impacts of some point sources by analyzing morphological composition of microplastic particles in various segments of coastal water areas and learning some regularities of their distribution. However, it is difficult to assess share of each source in the total inflow of plastics to the oceanwithout more detailed data. Since 2016 NOWPAP POMRAC collected data related to microplastic contamination in coastal water of the Russian part of NOWPAP, first publishing a case study of microplastic contamination in the coastal marine water area in the Russian part of NOWPAP region under the RAP MALI activity in 2018(“Microplastic Pollution in the coastal water of the Peter the Great Gulf: content and distribution. The first stage of survey”). POMRAC activity ‘Microplastics abundance in river runoff and coastal waters of the NOWPAP region’ was approved by the 21 IGM in 2017 as part of the activities on WG2 –River andDirect inputs of contaminants into the marine environment of the NOWPAP region. Its basic idea is to assess inflow of microplastic particles with rivers discharging into the marine area of NOWPAP and finding relations with plastic contamination in the adjoining coastal waters. This report describes the results of work performed under the abovementioned activityin 2017 and during biennium of 2018-2019, and follows findings indicated in previous POMRAC technical report #13.