Status of Nemunas catchment area in Lithuania

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1 «Improving water quality in the Neman catchment area through rewetting, wise wetland and river basin management» Status of Nemunas catchment area in Lithuania Ricardas Paskauskas, Nature Research Centre, Vilnius th December 2016, Kaliningrad

2 The total area of the Nemunas RBD in Lithuania (including the transitional and coastal waters) is km2 Latvia Russian Federation 75 % Belarus Poland NEMUNAS RBD MANAGEMENT PLAN,

3 Ecological status and ecological potential of rivers, lakes and ponds in the Nemunas RBD Rivers Lakes & ponds NEMUNAS RBD MANAGEMENT PLAN, 2015

4 The new Nemunas RBD Management Plan has been prepared in 2015 Unfortunately, it was indicated there of that the mandatory environmental measures and the planned programmes will not significantly reduce agricultural pollution and will not ensure that the concentrations of N and P compounds in all water bodies meet GES requirements. So, the implementation of these measures will not significantly affect the pollution loads transported to the Curonian Lagoon and the Baltic Sea!

5 The new measures proposed in Nemunas RBD management plan (2015) for the reduction of agricultural pollution are divided into 3 categories: 1. Mandatory national measures to reduce agricultural pollution: mandatory development of fertilisation plans in farms with more than 50 ha of arable land; mandatory growing of catch crops in farms with more than 50 ha of arable land, so that the area of catch crops constitutes at least 10% of the arable land. 2. Subsidised/promoted agronomic measures to reduce agricultural pollution in the basins of water bodies at risk where good ecological status will not be achieved even after the implementation of all mandatory measures: additional area of catch crops, i.e. expansion of the area of catch crops in farms with more than 50 ha of arable land and the area of catch crops constituting at least 15% of the arable land in other farms; expansion of the areas for crop rotation with 30% of leguminous crops; promotion of ploughless soil tillage. 3. Implementation of engineering measures to reduce agricultural pollution in the basins of water bodies at risk where good ecological status will not be achieved after the implementation of agronomic agricultural pollution reduction measures: transformation of the drainage system constructing horseshoe-shaped ponds at the drainage mouth; other engineering measures, such as construction of ponds in ditches increasing their crosssection and of artificial wetlands.

6 It is estimated that the supplementary pollution reduction measures provided for in the RBD management plans can reduce inputs into the Curonian Lagoon (Baltic Sea): 5,000 tons of nitrogen and 65 tons of phosphorus Is that enough?

7 The commitments for Lithuania under the new regulatory documents of HELCOM (2013) include the reduction of nutrient inputs into the marine environment of the Baltic Sea by 8,970 tons of N and 1,470 tons of P compared to the reference period ( ) HELCOM

8 Measures taken in Lithuania allowed significantly reduce the loads to the Baltic Sea HELCOM, 2015

9 In absolute values this means reduction up to 4,000 t of N and 801 t of P Considering the projected reduction in the nitrogen load (7,400 t N) as a result of at least partial implementation of supplementary agricultural pollution reduction measures, the HELCOM target (reduction of 8970 t N) in respect of this nutrient seems to be feasible.

10 The planed progress in the reduction of phosphorus loads seems to be less substantial ( t P) compared to the target (1470 t). If the total annual amount of P transported from the Lithuanian territory (including transboundary pollution) to the Baltic Sea should not exceed 1,151 tons According to the conclusions based on modelling results presented in the Nemunas RBD Management Plan (2015): Considering that the pollution coming from Lithuania represents only about 43% of total P transported by rivers Assuming that natural background phosphorus accounts for about 16% of the Lithuanian P loads the current pollution load should be reduced by about 20% the pollution load generated in Lithuania should be reduced by about 35% the pollution caused by human activities should be reduced by over 40% According to the authors of the study, this is hardly feasible

11 So, additional measures are required to reduce the inputs of phosphorus and, accordingly, nitrogen into the marine environment

12 The analysis of multi-annual marine status monitoring results indicates that average annual N and P concentrations in the open sea have been almost twice the limit values of good status. N P Off shore Near shore A much better situation in terms of the values of nutrient concentrations indicating good environmental status is in the nearshore of Lithuania.

13 In 2015 new Programme of Measures was prepared under Marine Strategy Framework Directive 2008/56/EC in order to achieve good marine environmental status by 2020

14 Measure T3PR1: To carry out a feasibility study on additional removal nutrients from wastewater discharged from treatment plants using bioaccumulation mechanisms (phytoplankton biomass growth) in order to reduce the input of nutrients into the sea Wastewater treatment at point pollution sources, should be improved and made more effective using the method which has already become widespread internationally when phytoplankton organisms and epiphyte algae are used for additional wastewater treatment Preliminary estimates: the amount of total N and P which could be removed from urban wastewater using phytoplankton and epiphytic algae could be up to 900 t and 90 t, respectively *** If the pilot project is successful, i.e. the benefit related to the removal of nutrients outweighs costs, the Wastewater Management Regulation should be supplemented with relevant provisions providing for reduction of pollution by nutrients

15 Measure T3PR4: To carry out a feasibility study on the zebra mussels (Dreissena polymorpha) growing and collection methods for the removal of nutrients from the Curonian Lagoon and other water bodies by stimulating and increasing the intensity of denitrification processes in the waters of the Curonian Lagoon 2013nhsustainablefisheries.blogspot.com The results of modelling of the zebra mussels population in the Curonian Lagoon showed that 25% of the biomass of the current population (up to 1,300 tons) can be grown additionally in the lagoon each year and its collection from the ecosystem would remove up to 89 tons of nitrogen and 15 tons of phosphorus.

16 LTR77 LTR138 Measure T3PR7. To carry out a feasibility study to determine seasonal trends in nitrogen fixation, denitrification and cyanotoxin production processes, distribution and extent of build-up, to analyse the impact of biological processes on the balance of nutrients in the Curonian Lagoon and to describe the effect of these processes on changes in GES indicators in the marine area Evaluation of N & P loads from Nemunas r. to the Baltic Sea LTR266 LTR13 LTR20 LTR13 Nemunas r. near Rusnė, LTR266 Minija r. near Suvernai, LTR20 Šyša r. near Šilutė, Minus loads from Belarus Plius LTR77, LTR138 Plus Gilija and direct tributaries denitrification? Preliminary estimation: 10,000 t/y nitrogen fixation?? Preliminary estimation: 1,500 and 20,000 t/y

17 Measure T3PR5: To carry out a feasibility study to analyse the possibilities of phytoplankton biomass collection in the waters of the Curonian Lagoon using floating gear and disposing the collected biomass in bioreactors, using it for agrotechnological needs or other purposes Phytoplankton biomass concentration technique and collection method (according to Gröndahl, 2009) Phytoplankton abundance calculations showed that the amount of biomass in the Curonian Lagoon (including the part of the Russian Federation) can range between 102,625 tons (2007) and 759,270 tons (2006). Based on stoichiometric relationships between substances in the phytoplankton biomass, the nitrogen content in the above-mentioned amount would be between 1,540 and 11,390 t and that of phosphorus between 160 and 1,150 t.

18 Benefits: Control of nuisance bluegreen algal blooms; Prevention of eutrophication and toxic exposure; Prevention of hypoxia; A timely and prompt removal of nitrogen fixating cyanobacteria Biomass utilization CH4 Useful Products: Lipids; proteins, carbohydrates.

19 Measure T3PR3: To dredge the channel at Panemunė for increasing the sedimentation of outwash material in the Nemunas River valley According to the results of natural studies (Adomaitis, Vaikasas, 2011) conducted in 2011, the turbidity of the Nemunas water flowing to the valley during a minor flood (2011) decreased by as many as 4 23 times depending on the distribution of currents and condition of herbaceous flora. The amounts of nutrients dissolved in water or depositing together with small suspended outwash material decreased at different rates: the amount of total nitrogen fell by around 4 times and the amount of total phosphorus dissolved in water by around 30%.

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