The share of Poland in the actual pollution status of Baltic Sea waters with nitrates in the light of HELCOM PLC research

Abstract The aim of the study was to analyze the results of the current research in the HELCOM PLC project on Poland’s share in the pollution of the Baltic Sea waters. The analysis considers annual update of the HELCOM Core Pressure Indicator, which monitors the implementation of maximum allowable nutrient loads (MAI), covering data from 1995 to 2018, assessment of progress in achieving national nutrient input limits (NIC assessment), covering data for the years 1995–2020, assessment of sources and pathways of nu- trients to the Baltic Sea environment by 2020 and comparative analysis at the level of source data from 1995 to 2018 for Poland. Analysis of the nutrient input trend over the 1995–2018 observation period showed a statistically significant 20 percent reduction in total nitrogen input to the entire Baltic Sea. Poland reduced the nitrogen input to all HELCOM basins from the 1997–2003 reference period by 11–26% and it has reached inflow limits in all basins, except the Baltic Proper (BAP), where the reduction remaining to be achieved before 2020 was 30578 t, i.e. 20% of the NIC. The main loads of total nitrogen from Poland to the Baltic Sea are delivered via inland waters (indirect sources) and come from agriculture (57%). Actions at the European Union level, including monitoring the Baltic Sea environment and indicating sources of threat, are necessary for continuous implementation.