With its ‘Blue Growth Strategy’, the European Union aims to boost its aquaculture production, both to meet the growing demand for seafood and to foster economic growth and employment. To this end, the 2014 Common Fisheries Policy contains several measures to stimulate aquaculture, as does the 2014-2020 European Maritime and Fisheries Fund. Simultaneously, however, the Marine Strategy Framework Directive obliges all EU Member States to improve the environmental condition of European seas and to reach Good Environmental Status by 2020. Given that excessive nutrient input poses a significant environmental problem in the Baltic Sea, these two policies risk an inherent incompatibility unless carefully managed.  

Early October this year, the Bund für Umwelt und Naturschutz Deutschlands e.V. (German member of SAR) held a small symposium in Kiel, Germany. Here, invited representatives from politics, science, aquaculture industry and environmental organisations discussed political developments at national, regional and EU level, and evaluated the possibilities presented by forms of aquaculture with minimal nutrient input to the Baltic.

Modern aquaculture encompasses many different production methods and target organisms. Farming options include open cage systems in natural waters, pond systems, or closed recirculating facilities operated on land, independent of natural water bodies. Open cage fish aquaculture systems in marine waters present a number of environmental challenges, such as nutrient loss through excess food and faeces, thereby exacerbating eutrophication.

Baltic sea eutrophicationB


The symposium firmly established that the ecological status of the Baltic Sea demands any further nutrient input be minimised. Presentations and subsequent discussions pointed to Integrated Multitrophic Aquaculture (IMTA) as the only acceptable method of open cage fish farming in the Baltic. In this method, the nutrients introduced by the farmed fish would be absorbed by a pre-determined amount of mussels, preventing excess nutrients from entering the marine ecosystem. However, IMTA systems have not been tested at full industrial scale and the no-emission theory has yet to be proven in practice.

Land-based recirculation aquaculture systems (RAS) seem to promise the best available technology and seem ideally suited to the Baltic region, as they do not introduce further nutrients to marine waters. The polluter’s pays principle is embedded within RAS, with the polluter paying for cleaning and reusing the water, to a large extent. The production of fish close to the consumer market also represents an environmental advantage. However, questions remain about the species farmed, animal welfare, energy requirements, water recycling and technical issues. To date, few RAS facilities produce fish for the open market, as most are pilot or scientific projects whose fish products are too expensive for general sale.

For a semi-enclosed sea such as the Baltic, cooperation among all neighbouring countries is necessary to ensure protection of this important environmental resource. Such regional coordination is a mandatory element of both the Espoo Convention and EU cross-border cooperation. Currently, Denmark is planning 600 square metres of open cage aquaculture facilities in the Kattegat, as well as pioneering land-based RAS. In both cases, cooperation across country borders would benefit the Baltic Sea.

Lastly, the symposium discussed the underlying assumption that aquaculture should fill the gap created by the dwindling wild catch as a result of overfishing and stock loss. If fish were to be seen as a rarely consumed delicacy rather than a product for mass consumption, the quantities needed would be lower, making the marketing of high quality products from land-based production easier.

Net cages in Norway with copyrights2