"INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT" Palazzo Zorzi, Venice, Italy, 24-26 March 2004

TRANSBOUNDARY COOPERATION EXPERIENCES IN THE VISTULA LAGOON BASIN GAINED DURING MANTRA-EAST RESEARCH PROJECT

Małgorzata BIELECKA *, Andrzej LEWANDOWSKI **

*Institute of Hydroengineering of the Polish Academy of Sciences, Kościerska 7, 80-953, Gdańsk, Poland, (E-mail: [email protected]) **GEOMOR - Geoscience and Marine Research & Consulting Co. Ltd, Kościerska 5, 80-328, Gdańsk, Poland, (E-mail: [email protected])

Keywords: transboundary water management, WFD, water quality, modelling, data base, monitoring

ABSTRACT The Vistula Lagoon is one of the largest transboundary lagoons in the Southern Baltic Sea. It is shared by two countries: Poland (EU-accession state) and Russia (non-EU state). Within just recently finalised EU FP5 research project ’Integrated strategies for the management of transboundary waters on the Eastern European fringe’ (MANTRA-East) issues of transboundary water management and cooperation in the Vistula Lagoon drainage basin were analysed. This was an additional case study area in the project as the main one was Lake Peipsi. The main objective of the project was implementation of the common water management system that will allow achieving goals of WFD. The project focused on analysis of existing monitoring systems, long-term changes in water quality and biota, and uses modelling tools for assessment of ecological status and forecasts in the WFD context. The participation of end-users from both countries assured proper realization of the project and dissemination of the project results to water managers in order to support decision-making in the basin. In this paper we focus on experiences gained from the project and recommendations that were proposed for water managers of the Vistula Lagoon, as a result of scenario approach and the experiences.

INTRODUCTION The Vistula Lagoon (Fig. 1) is one of the largest transboundary lagoons in the S. Baltic Sea.

Figure 1: Location of the Vistula Lagoon and main discharging rivers.

Primor:skaya Nelma POLAND it Grayevka a tr Pregel S sk Kaliningrad iy lt a B Prokhladnaya

Vileyka Mamonovka RUSSIA Krynica Morska Pasleka POLAND Bauda Szkarpawa Frombork Tolkmicko

Nogat Elblag

1 "INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT" Palazzo Zorzi, Venice, Italy, 24-26 March 2004

It is a shallow (av. depth 2.7 m) coastal ecosystem. The Lagoon has an elongated shape, going from south-west to north-east, with a length of 91 km. The average width of the Lagoon is about 9 km, at the widest point - 13 km. The surface area is 838 km2, of which 473 km2 belongs to Russia, and the remaining part to Poland (Łomniewski, 1958). The length of the coastline is of about 270 km, and the volume of water in the Lagoon is about 2.3 km3. The average depth of the Lagoon is 2.7 m, and the maximum natural depth is 5.2 m close to the Baltiysk Strait. The Vistula Lagoon is separated from the Baltic Sea by the Vistula Spit - a sand peninsula 55 km long. The Lagoon exchanges water with the sea through the Baltiysk Strait, which has a width of approximately 400 m, length of two kilometres and the average depth of 8.8 m. Baltiysk Strait continues up to the harbour of Kaliningrad as a fairway (navigation channel) crossing the Lagoon. The channel is twice deeper than the largest natural depth in the Lagoon. Despite its relative narrowness, it plays an important role as a way of salt transport from the Gulf to the Lagoon. With respect to salinity the Vistula Lagoon is found to be a transitional area. The average salinity (1950 -1965) for the eastern part of the Lagoon (spring-autumn) is 2.5-4.3 PSU, for the central part 3.9-5.0 PSU, and for the southern part 1.0-3.4 PSU (Lazarenko and Majewski, 1975). This is a result of salt water inflows from the Baltic Sea that influence all aquatic areas of the Lagoon, including the mouth of the Pregola River. At the Baltiysk Strait salinity may reach 7 PSU (Bocheński et al., 1999). The catchment area of the Vistula Lagoon is 23,871 km2 and the average retention time is about 6-7 months. There are more than 20 rivers discharging directly to the Vistula Lagoon. Among them the most important are: Pregola, Elbląg, Pasłęka, Nogat, Prokhladnaya, Mamonovka, Bauda, Primorskaya and Szkarpawa (Fig. 1). The main part of the annual fresh water inflow (40%) is coming from the Pregola River.

The Vistula Lagoon with its drainage basin is shared by two countries: Poland and Russia. Poland is the EU member starting from May 1st 2004 but Russia is not, therefore they face different obligations with regard to water management of the lagoon drainage basin. Poland has to implement WFD but Russia does not have such obligation. Described situation may result in potential transboundary conflicts. The lagoon itself is subjected to point and non- point sources of nutrient loads so only close cooperation and integrated management would provide successful solutions. Within EU Mantra-East project main focus was put on analysis of existing monitoring systems, long-term changes in water quality and biota, and use of modelling tools for assessment of ecological status and scenarios in the WFD context. Four basic scenarios where considered: 1 – Business As Usual which was the same as Crisis Scenario, 2 – Not Optimal Target Development Scenario, 3 – Optimal Target Development Scenario, 4 – Isolationists Scenario (Przedrzymirska, Lewandowski, 2004). The participation of end-users from both countries was crucial to assure proper realization of the project and dissemination of the project results to water managers in order to support decision-making in the basin. The general Mantra-East approach was given by Stalnacke and Gooch (this volume). That approach was followed in the Vistula Lagoon case study. Some serious water management problems became evident as the project progressed. The main problems defined concerned: 1. Water management structure, which is not clear and effective in both countries. Cooperation problems exist between water managers. There is no common strategy formulated for the lagoon management. In both countries institutional structure and legislation are different.

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2. Data collection comprising problems of data availability, comparability, quality, exchange possibility. As a consequence establishment of common monitoring programme and database was proposed. 3. Ecological modelling, as there were not enough data to calibrate models properly and available data were inaccurate causing calibration problems. In search of solutions to those problems usage of operational modelling tools, to which both countries have free access (HIRLAM, HIROMB), was proposed. In order to facilitate effective Vistula Lagoon drainage basin management, one modelling system was recommended and installed at Polish and Russian end-users’ institutions, what was justified by the project results.

THE VISTULA LAGOON HIGH-LIGHTS Main results of research conducted within a project may be summarized in form of high- lights. The most important ones are listed below. · Light availability is a very important factor governing the primary production in the Lagoon. Very important factor governing the primary production is light availability in water column depending on the amounts of suspended matter. Its concentrations are very high, several times higher than values observed in rivers. Such large amounts of suspended solids result from frequent resuspension of the bottom sediment, which is a typical feature for water bodies as shallow as Vistula Lagoon and exposed to winds. Due to the dominant influence of resuspended matter on the light extinction in the water, only moderate changes in water transparency may be expected as a result of nutrient loads reduction (Zalewski et al., 2004).

· The Vistula Lagoon is, in general, limited by nitrogen. Model simulations indicated that the limiting factors for phytoplankton growth in the Vistula Lagoon were inorganic phosphorus in short periods in spring and inorganic nitrogen in summer and early autumn. Changes of phosphorus loads first of all may influence the spring phytoplankton bloom, while changes of nitrogen loads will affect phytoplankton biomass in summer season (Zalewski et al., 2004). It was also confirmed by N/P ratio analyses and bioassay experiments of nutrient limitation presented by Margoński et al. (2003).

· Nitrogen fixation by cyanobacteria may annihilate efforts of nitrogen load reduction, if phosphorus concentrations in summer are not reduced. At present excessive phosphate concentrations are observed in the lagoon in summer period, partly as a result of the release from bottom sediments. This creates favourable conditions for nitrogen-fixing cyanobacteria development, which occasionally form blooms over 100 mg chla m-3. Therefore reduction of phosphate concentrations in summer is needed, in addition to nitrogen reduction, if summer phytoplankton blooms are to be suppressed.

· There is little retention of phosphorus in the Lagoon. Nitrogen retention is more substantial. Nutrient budget calculations suggest, that there was little retention of phosphorus in the Lagoon, while the retention of nitrogen was more substantial. The important pathway in nitrogen cycle in the Lagoon appears to be the denitrification (Zalewski et al., 2004).

· The Vistula Lagoon ecosystem may quickly react to changes in nutrient loads. Due to short freshwater residence time (ca. 7 months) the Vistula Lagoon ecosystem

3 "INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT" Palazzo Zorzi, Venice, Italy, 24-26 March 2004

may quickly react to changes in nutrient loads. According to the model simulations, the pelagic system may stabilize at new levels within 2 years. However, at the present state of model development, the reaction of bottom sediments cannot be reliably predicted (Zalewski et al., 2004).

· The present ecological status of the lagoon may be estimated as “moderate”. Several water quality (total phosphorus and total nitrogen, chlorophyll a) and biota (phytoplankton and zooplankton) indices were taken into account. The analysis of existing information led to the conclusion that, in the case of the Vistula Lagoon, the benthic invertebrate fauna should be excluded from valuable biological quality elements at the present stage (Margoński et al. 2003).

· Surprisingly despite the increase of nitrogen loads in Target Development scenario, the phytoplankton biomass may decrease in spring season. Despite the increase of nitrogen loads in Target Development scenario, the phytoplankton biomass may decrease in spring season, as a result of reduced phosphorus concentrations. In the second half of growth period, when phosphorus ceases to be a limiting factor, phytoplankton biomass may slightly increase (Zalewski et al., 2004).

· Modelling may be a valuable tool for ecological status assessment. To assess reference conditions modelling has been applied (Delft3D WAQ model).

· “Good” to “high” status in the Lagoon may be reached. It is possible to reach the “good” to “high” status when the Optimal Target Development scenario is applied (Zalewski et al., 2004), which assumes Good Agricultural Code in the Vistula Lagoon drainage basin and point sources pollution reduction (Przedrzymirska, Lewandowski, 2004). In this situation substantial reduction of phytoplankton biomass may be expected over the most part of the year.

· “Refreshed” transboundary cooperation between Polish and Russian end-users. During the project realization intensive contacts with the end-users have been established encouraging them to more intensive cooperation, information exchange and stronger involvement in bilateral actions towards improvement of water management in the Vistula Lagoon and participation in common projects.

Experiences gained during the project realization allowed to define main problems faced in Vistula Lagoon drainage basin management and basing on that, to formulate comprehensive recommendations for the end-users.

RECOMMENDATIONS FOR THE VISTULA LAGOON MANAGEMENT Reduction of nutrient loads from point sources Since 1990 till 2000 a significant progress has been done with respect to construction of waste water treatment plants in Poland. In 1991 47% of sewage was only mechanically treated and 53% - biologically. In 2000 only 1% was treated mechanically, 4% was untreated sewage, 46% - biologically treated and 49% - biologically treated with denitrification and chemical removal of phosphorous. Whereas in Russia in 1998 74% of sewage was treated only mechanically, 17% - biologically and 9% was not treated at all (Przedrzymirska, Lewandowski, 2004). This is a considerable disproportion and has negative impact on water quality especially in Russian part of the lagoon. Therefore it is recommended to construct in Kaliningrad

4 "INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT" Palazzo Zorzi, Venice, Italy, 24-26 March 2004 region more new WWTP and modernize in Kaliningrad and Poland old waste water treatment plants to reach biological treatment with denitrification and P removal as a target.

Reduction of nutrient loads from diffuse sources Mostly agriculture contributes to diffuse sources of pollution. Therefore to reduce the loads it was proven that following actions should be taken: -Proper fertilization of fields (less mineral fertilizers and more natural), -Proper storage of manure, urine, slurry, -Education of farmers in good agricultural practices (financial support: cheap loans, etc.).

As it has been indicated by Optimal Target Development scenario (3) even though fertilization level will increase significantly, pollution load to the Lagoon will be reduced comparing to present state, if good agricultural practices are followed by farmers. In case they are not followed as in Not Optimal Target Development (2) scenario, deterioration of ecological status of the Lagoon should be expected.

At present the richest source of nitrogen loads are diffused sources (where agriculture plays the most important role). It is expected that their role will get even more important comparing to point sources of pollution, when the agriculture will develop according to Target Development scenarios 2 and 3 (Fig. 2.). Therefore with respect to nitrogen more focus should be put on diffuse sources reduction than point sources.

Figure 2.: Distribution of nitrogen loads to the Vistula Lagoon from different sources and for different scenarios.

Distribution of N loads from different sources for all scenarios

35000,00 r

a 30000,00 e y / 25000,00 s e

n 20000,00 n o t

15000,00 n i 10000,00 d a

o 5000,00

L Existing loads 0,00 Diffuse N Agriculture N PointS N Scenario 2 Scenario 3 Source of load Scenario 4

In case of phosphorous loads situation is slightly different. At present moment most of phosphorous comes from point sources. According to future scenarios this relation will change, as P from point sources will be removed due to improved waste water treatment. In that situation again diffuse sources will start to play important role and focus should be put on further P reduction from those sources (Fig. 3).

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Figure 3: Distribution of phosphorous loads to the Vistula Lagoon from different sources and for different scenarios.

Distribution of P loads from different sources for all scenarios

1000,00 r a

e 800,00 y / s e

n 600,00 n o t 400,00 n i

d

a 200,00 o

L Existing loads 0,00 Diffuse P Agriculture P PointS P Scenario 2 Scenario 3 Source of load Scenario 4

Reduction of nutrient loads from atmosphere Atmosphere is a well known as a rich source of nitrogen loads. In our scenarios its influence on total load to the Vistula Lagoon was not investigated, however it is obvious that nitrogen emissions to atmosphere should also be reduced.

Necessity to set up of a common Polish / Russian monitoring program of the Vistula Lagoon, Baltiysk Strait and discharging rivers During realization of the project we have come across serious data problems. Most important issues concerned: · Data availability in terms of possible exchange between both sides and partners. Measurements are carried out by different institutions (those responsible for state monitoring and scientific institutions). Information exchange between them (both inside the country as well as between the two countries) is difficult, however a common data base for Kaliningrad region already exists in Kaliningrad. These problems are a result of different internal regulations and legislation. In order to acquire, use, share and exchange data between countries and partners in the project special agreements between institutions were required. · Data availability in terms of sampling stations location, measured parameters, frequency, periods of measurements (no winter measurements) – as a main source of uncertainties. Not too many stations are located around the Lagoon and sometimes they are not situated in most optimal spots. For instance in Russian part of the lagoon stations are located in central part, whereas in Polish part – along shores of the lagoon mainly. This makes interpretation of measurements more difficult and not comparable. Also not all water quality parameters are measured, frequency of measurements in Polish and Russian parts of the lagoon in different and during the winter period (December – March) there are not measurements at all. Not all rivers discharging to the lagoon are monitored and in those that are monitored, discharges are not measured. As a result lots of uncertainties occur and analysis of ecological status of the lagoon as well as set up and calibration of numerical ecological models gets very difficult and problematic.

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· Data accuracy and comparability (different analytical methods; different accuracy; not only between countries but also between laboratories). This is another source of uncertainties that again influences proper ecological status assessment as well as ecological modelling. · Coordinated monitoring for the whole of the Lagoon does not exist therefore spatial distributions of water quality and ecological parameters in whole Lagoon are not available for the same period of time (not even day or week).

Taking into account all those problems it is recommended to set up a common Polish/Russian monitoring program of the Vistula Lagoon, Baltiysk Strait and discharging rivers comprising following parameters: 1. Meteorological: wind forcing, temperature, precipitation, pressure, atmospheric deposition; 2. Hydrological including measurements of river discharges, water levels, velocities in the lagoon as well in Baltiysk Strait at several depths; 3. Water quality parameters in the lagoon and rivers, 4. Biological parameters in the lagoon and rivers, 5. Sediment composition in the lagoon.

Studies of sediment / water interactions Sediment can be a very rich source of phosphorous and nitrogen. It interacts with water releasing the nutrients to water column or adsorbing them from water. As a result it influences strongly nutrient budget of the whole Lagoon. Due to lack of data this problem was not investigated in this project. However it is recommended to study sediment / water interactions in future.

Establishment of a common Polish / Russian data base As a result of common and coordinated monitoring, the common Polish / Russian data base should be established in order to enable efficient information exchange between countries, integrated Vistula Lagoon management and beneficial for both countries decision making.

Usage of the same modelling tools It is recommended to use the same modelling tools for the Vistula Lagoon, especially that currently as a result of the project, both countries have Mike 21 model installed at the end- users institutions responsible for the water management of the Lagoon. This will enable easier comparison of modelling results, better information and experiences exchange, and it may be used for integrated scenarios and water management planning.

Usage of operational models complementary to actually measured data Operational models that function for the Baltic Sea, such as meteorological HIRLAM and hydrodynamic HIROMB, freely accessible for most of the Baltic countries, may be used for the boundary conditions input in case of problems with real monitoring data acquisition. It was proved in the project that such concept may function quite well and may be used for forecasts and emergency situations such as oil spills, storm surges, etc (Bielecka, et al., 2003).

Application of numerical models to establish reference conditions in the Vistula Lagoon Reference conditions were calculated using the Delft 3D water quality model (Margoński, et al., 2003) as an example of procedure that may be used for the water body where there is: - lack of reference water bodies,

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- existing paleo-ecological information is incomplete and difficult to interpretation because of the unstable characteristics of the lagoon: connection or disconnection with the Gulf of Gdansk in history, - anthropogenic alterations caused the Vistula Lagoon change from freshwater to brackish water body and, therefore, historical data were not very useful for reference condition assessment, - comparison of nutrient concentrations was reasonable over the last 30 years only, taking into account differences in analytical methods, - the vast majority of case studies dealt with phosphorus limited water bodies (e.g. Lake Peipsi). However, the Vistula lagoon is, in general, limited by nitrogen. Several assumptions were made: “clean rivers” should discharge to the lagoon and the waters of the Gulf of Gdansk need to be “clean” as well. Since it was very hard to find reliable reference conditions for nitrogen concentrations in the atmosphere, the atmospheric deposition was applied as it is now. The main source of uncertainty was the assessment of sediment-water exchange. The information on possible change in nutrient transport between sediment and water was scarce, as this kind of research was not carried out in the Vistula Lagoon. The model stabilized after six years of simulations and results of the sixth year were considered as a reference levels for the water quality parameters and chlorophyll a concentration. Next the monitoring results were compared against the reference conditions for that type and expressed as an Ecological Quality Ratio. To calculate EQRs of each water quality parameters, the monthly reference conditions for the April-November period were used. Each measurement was related to reference condition calculated for particular month. The reciprocal ratio (EQR = refcond / measured) was applied as nutrient concentrations increase with an increasing human pressure. In some cases, the ratios obtained were higher than “one”. Such results were classified as “1.00” as they achieved the high quality status. Taking into account the water quality and biota indices the present ecological status was estimated as “moderate”. Ecological status assessment made for scenarios indicated that in case of optimal target development scenario it is possible to reach “high” status in the Vistula Lagoon. It is recommended to use this approach to establish reference conditions and ecological status according to WFD requirements.

Establishment of a common Polish / Russian forum for dissemination of information on problems, proposed solutions, activities and projects carried out in the Vistula Lagoon drainage basin. During the project it was noticed that dissemination of information on different activities and projects carried out for the Vistula Lagoon and its basin is very poor. This situation became evident during a project meeting in Gdansk on 15 –16 December 2003, when several different project carried out in the region where presented. Apparently some activities within different running and proposed projects were overlapping since there was no knowledge about the ongoing projects and cooperation between them. Therefore it is recommended to establish of a common Polish / Russian forum for dissemination of information on problems, proposed solutions, activities and projects carried out in the Vistula Lagoon drainage basin.

CONCLUDING REMARKS Presented case study realized within MANTRA-East project proved that it was possible to acquire very interesting scientific results even though we faced many uncertainties mostly related to available data. These could affected accuracy of tools that were used for simulating different scenarios of nutrient discharges to the Vistula Lagoon. Those data imperfections

8 "INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT" Palazzo Zorzi, Venice, Italy, 24-26 March 2004 were a direct result of transboundary and also internal management problems in the area. Therefore to overcome those problems in future improvement of transboundary cooperation is necessary, as well common actions has to be taken, like common monitoring program, common data base, common tools for hydrological and ecological predictions as well as efficient information dissemination and exchange system. Those problems where pointed out to the Vistula Lagoon water managers. As a result they declared intention for improvement of transboundary cooperation in the Vistula Lagoon area.

ACKNOWLEDGEMENT The European Union (Contract EVK1-CT-2000-00076) is acknowledged for financial support.

LITERATURE Bielecka M., Kaźmierski J., Ewa Jasińska E., Wojciech Majewski W., Walkowiak A., Witek Z., Zalewski M., Wielgat M., Staśkiewicz A., Lewandowski A. 2003. „Hydrodynamic and water quality models of the Vistula Lagoon – description and calibration results”, Deliverable D6cVL, 52 pp. Bocheński J., Talaga A., and Olech S. 1999. Conditions of the integrated management of the Vistula Lagoon coastal zone (in Polish). Report for the Polish Ministry of Environmental Protection, Natural Resources and Forestry. Lazarenko, N. N., and Majewski, A. (Eds.). 1975. The hydrometeorological system of the Vistula Lagoon (in Polish), IMGW, Wydawnictwo Komunikacji i Łączności, Warszawa, 518 pp. Łomniewski, K. 1958. The Vistula Lagoon (in Polish). Prace Geograficzne, Polska Akademia Nauk, Instytut Geografii, PWN Warszawa, No.15. 106 pp. Margoński P., Horbowa K., Gromisz S., Witek Z., Zalewski M. and Warzocha J. 2003. Trophic and ecological status of the Vistula Lagoon. MANTRA-East Deliverable D3eVL, 47 pp. Przedrzymirska J., Lewandowski A. 2004. Estimation of nutrient loads and scenarios for nutrient loads to the Vistula Lagoon. MANTRA-East Deliverable D5dVL, 68 pp. Stalnacke P. and Gooch G. 2004. Experiences gained from a research project on an integrated approach for management of transboundary waters on the new Eastern EU- border region. In Proceedings from Conference on INTEGRATED WATER MANAGEMENT OF TRANSBOUNDARY CATCHMENTS: A CONTRIBUTION FROM TRANSCAT. Palazzo Zorzi, Venice, Italy, 24-26 March 2004 Zalewski M., Witek Z., Wielgat M., Bielecka M., Margoński P. 2004. Scenario results for the Vistula Lagoon and final recommendations. MANTRA-East Deliverable D6dVL, 37 pp.

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