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