The Sole Question. Assessing the sustainability of fishing versus farming

Fish stocks in the world are declining, but the demand for fish products is increasing. Aquaculture practices are increasing because of this gap between supply and demand. Therefore it is important to determine which production system has the least environmental impact. In this research the sustainability of two sole production systems for the Netherlands is estimated. The sustainability is defined as a combination of four factors: energy requirements, direct and indirect land use, environmental stressors and ecological impact. Several methodologies are used to calculate the impact. The assessment of the indirect land use is based on the Ecological Footprint method. The environmental stressors are calculated based on a Life Cycle Analysis method. The ecological impact is estimated by using a questionnaire from the North Sea Foundation. Three factors are combined in a triangular diagram to visualize the overall environmental impact and to compare the two production systems. For all three factors in the diagram; energy requirements, ecosystem support area (or indirect land use) and ecological impact, the fisheries production system has a higher value. That indicates that for sole the aquaculture production is the more sustainable production system. Both production systems can be improved to reduce their impact on the environment. For fisheries this can be achieved through policy measures. Hereby the fishing intensity will be reduced resulting in a healthier fish stock and less energy needed to catch the same amount of sole. For aquaculture improvements can be achieved by making adaptations in the production system where the most important one is achieving a more efficient water circulation system to reduce the energy requirements. Although the methodologies being used in this research are not completely sufficiently adequate on their own, in combination they are proper tools to give an overview of different aspects of the sustainability of the two production systems.