Reduction of nutrient emission from Polish territory into the Baltic Sea (1988–2014) confronted with real environmental needs and international requirements

Abstract

Eutrophication of the Baltic Sea is considered a major threat to its ecological status. We present and discuss Polish riverine flow normalized loads of total nitrogen (TN) and total phosphorus (TP) discharged into the Baltic Sea in (i)1988–2014, (ii) periods of maximum TN (1992–1994), TP (1988–1991) emission, (iii) the reference period (1997–2003) established by the Helsinki Commission (HELCOM), (iv) 2012–2014, last years of our study. Despite considerable nutrient load reductions prior to the HELCOM reference period, Poland is expected to reduce TN and TP loads by 30% and 66%, respectively. In the light of our historical and up-to-date findings defining ecological status of the Baltic Sea, we suggest that the proposed TP load reduction is overestimated and its realization may lead to (i) undesirable consequences for the Baltic ecosystem, (ii) would require a decline in TP concentrations to 0.067 mg P dm-3 (the Vistula River) and 0.083 mg P dm-3 (the Oder River), values reported for pre-industrial times. The current nutrient concentrations in the Vistula and Oder safely comply with the requirements of the Water Framework Directive. We also comment on the top-down and bottom-up effect resulting in quantitative and qualitative reorganization of the Baltic ecosystem, a phenomenon already observed in the Baltic Sea.

Long-term changes in nitrogen and phosphorus emission into the Vistula and Oder catchments (Poland)—modeling (MONERIS) studies

“…The basic input data into the model encompassed (i) mean annual N and P loads at the lowermost monitoring stations on the Vistula (Kiezmark) and the Oder River (Krajnik Dolny) in 1995–2015 (Pastuszak et al 2018 ; GUS 2016 ), (ii) precipitation (Górski 2006 ) and own calculations conducted by the Institute of Soil Science and Plant Cultivation, (iii) statistical data on changes in population (BDL 2017 ), (iv) changes in land use (GUS 1991-2017 ), and (v) wastewater infrastructure with values of N and P emission from point sources (GUS 1991-2017 ). Values of the above parameters were calculated for the Vistula and Oder basin and GIS software (ArcView 3.3), as well as digital maps were applied in calculations.…”

Managing Eutrophication in the Szczecin (Oder) Lagoon-Development, Present State and Future Perspectives

“…Monitoring of nutrients in Oder River is conducted in Krajnik Dolny (Kowalkowski et al, 2012;Pastuszak, 2012a,b) at least once a month (Jadczyszyn and Rutkowska, 2012). Riverine data collection started in 1988 and has been elaborated by Pastuszak et al (2018). Reconstructions prior 1988 were used from Behrendt et al (2008) and from Baltic Nest Institute (Wulff et al, 2013).…”

Spatial Effects of Different Zebra Mussel Farming Strategies in an Eutrophic Baltic Lagoon

“…The simulation model had a horizontal resolution of 150 m and 20 vertical layers, which adapted their thickness to the density (Hofmeister et al, 2010;Gräwe et al, 2015). The model was run for 9 years (2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015), forced with realistic weather conditions, provided by the operational model of the National German Weather Service with a spatial resolution of 7 km and a temporal resolution of 3 h. Nutrient loads for Oder river were taken from Pastuszak et al (2018) and were provided for the German rivers by LUNG. Boundary data was taken from a previous simulation covering the western Baltic Sea with a horizontal resolution of 600 m FIGURE 1 | Simplified sketch of the mussel farm module (black rectangles) and its integration into the model system by calculating changes of Chlorophyll, detritus, PO 3− 4 , NH + 4 and Oxygen.…”