Eutrophication of the Baltic Sea

The interactive decision support system NEST links information on the Baltic Sea environment to the costs of different measures to improve it. NEST works out the lowest cost of achieving a desired environmental improvement and recommends what action to take in which countries. It uses models that combine knowledge from the areas of ecology, physical oceanography, biogeochemistry, hydrology and economics to form a single decision support system. Using NEST, decision makers in the Baltic Sea region can produce scenarios to help them decide what measures to introduce. The system is aimed mainly at decision makers in the Helsinki Commission (HELCOM) framework and those involved in implementing the EC Water Framework Directive.

User-friendly for Baltic Sea countries
Among the data fed into the system are details of how much nitrogen and phosphorus are finding their way into the Baltic, and how they are getting there. They also include information on how movements of water affect the different marine basins of the sea.

A measure or an emission along the coast of Poland , for example, has effects as far away as the Bothnian Sea.

‘Nowadays, it is generally accepted that what happens, say, in one coastal water usually depends on the environmental state of the Baltic as a whole,´ says Fredrik Wulff, scientific coordinator of MARE. ‘That also means there is now a consensus on the need for all the littoral states to play their part in improving the Baltic Sea environment.´

Users of the system can enter the goals or types of goals they wish to achieve, such as an increase in cod stocks or improved water transparency. Or ask what the transparency will be with a given level of nutrients. The system takes account of a wide range of data fed into it and works out what action needs to be taken to attain the stated goal at the lowest possible cost.

‘For example, you can find out the total cost of measures to achieve a particular objective, but you can also ascertain what proportions of that sum should be invested in each country,´ explains Sif Johansson, MARE´s programme director. ‘It´s also possible to produce scenarios showing how the total cost will be affected if certain measures aren´t carried out in a particular country. In addition, decision makers can adjust the costs of different proposals and obtain scenarios setting out what can be achieved for a smaller or larger sum of money.´

If, for example, you wish to improve water transparency by two metres, NEST tells you that action should primarily be taken in Poland and that an upgrading of sewage treatment plants would be the most cost-effective option.

Scientific arguments
NEST is not quite ready to be used yet, but there is not very much to be added.

‘We now have a system that works, and the people who use it basically feel it is ready,´ says Fredrik Wulff.

The system can be used at two levels, a standard and an expert level, the latter involving greater detail. Much of the work now being done is concerned with fine-tuning the system, without making it too complicated for the user.

‘One aspect that still needs improving is the component dealing with river catchment areas. In September we hope to be able to incorporate the time dimension in a more effective way,´ says Wulff. ‘Users need to be able to find out how long it will take for a measure implemented in one catchment to reduce inputs to coastal waters, or how long it will take to achieve a given target for the marine environment. If Poland changes the way it uses chemical fertilizers, how long will it be before the Baltic Sea environment is affected?´

One difficulty for politicians and other decision makers responsible for the Baltic has been the fragmentary nature of the information available. One aim of MARE, therefore, has been to collate data and make them more accessible to users.

‘MARE offers scientific arguments about what measures are important or necessary in reducing Baltic eutrophication,´ Wulff explains.

Put to the test
Getting the decision support system to where it is today has not been plain sailing. Its strength - but also the source of the difficulties - is that researchers with different areas of expertise have been involved in its development. In all, the MARE team comprises some thirty people. Ecologists, hydrologists, statisticians, geologists, oceanographers and economists have worked side by side, and cultural differences have sometimes been quite a problem.

‘Most researchers are primarily experts in their own specific areas, and few have an overall view,´ Fredrik Wulff points out. ‘MARE has adopted an integrated approach based on these different perspectives, in terms both of how you view reality and what is more or less important in tackling Baltic eutrophication. We´ve learnt a lot over this period, and now I feel that our scientific cooperation is working well. We´re attracting new postgraduates and other researchers to the group, and our collaboration with various international research programmes is strengthening the work we´re doing.´

Up to now, MARE has resulted in nine doctoral theses, and more are on the way.

To make the system user-friendly, it has been continuously tested on different groups of users.

‘We´ve held several workshops, chiefly for people from the Helsinki Commission, at which we´ve tried out a number of scenarios. We´ve also tested the system on courses for students and researchers. The goal is to make the system so user-friendly that people will be prepared to run it themselves. And in fact that has started to happen,´ says Wulff.

‘The two years remaining of the programme will mainly be devoted to adding supplementary components to the system and updating the data on which it is based. We´ll also be producing a number of scenarios in collaboration with HELCOM, for example showing what will happen to the Baltic Sea environment when Poland has implemented all the water directives.´
 
Tool for advisers
Fredrik Wulff does not expect politicians to become hands-on users of the system, but believes that their advisers and experts will find it useful.

One task during the final years of MARE will be to find a permanent home for NEST on completion of the programme. Wulff feels that future development of and support for the system should be entrusted to an international institute of some kind.

‘When we launched the project, we saw HELCOM and national agencies around the Baltic as the main users. But with all the Baltic Sea states apart from Russia joining the EU on 1 May, the basic premises have changed.´

One drawback with HELCOM is that its activities and commitments are entirely voluntary; there is nothing to force a state to carry out action which it has decided on. An EU decision or directive, on the other hand, is legally binding. Consequently, the EU could prove a more important end-user in the years to come, and the European Environment Agency (EEA) is now showing an interest.

‘NEST will be of use to all the Baltic Sea countries as a basis for drawing up different “what if" scenarios. One advantage is that, for the first time, all the data are available via a single system,´ says Jacqueline McGlade, EEA Executive Director and a member of the MARE board.

At the same time, she points out that, to make NEST as effective as possible in the future, new data need to be added to the system as they become available. In addition, the system has to take into account the economic feasibility of different measures.

‘The important thing now,´ McGlade concludes, ‘is to launch NEST and let users give feedback and suggest improvements.´