Quotas and other EU management measures (e.g., closed areas, closed seasons, gear specifications) regulate how much fish is allowed to be taken from a population and how fishery impacts marine ecosystems. Fundamental to all management regulations are data collections and model calculations as being performed by the fisheries research. In Germany the Thünen institute signs responsible for carrying out this work.
In the work unit "Marine Living Resources" we quantify and assess the impact of the exploitation of fish and other marine organisms on their populations (being called stocks in fisheries science). The results of our work find their way into quota and management recommendations and hence directly into the European fisheries management. Moreover, they contribute to the development of an ecosystem approach to fisheries management, supporting a responsible handling of the seas and its inhabitants by at the same time ensuring a sustainable supply of man with high quality food from the seas.
Data from commercial fisheries (e.g., catch statistics, samples from observer trips) and of own fisheries independent surveys help us to deliver important information on the different fish stocks and fisheries. Along with our colleagues from Europe and North America we use these data inside the International Council of the Exploration of the Sea (ICES) to assess the status of Atlantic stocks, to predict future developments and to identify risks for marine ecosystem. Partly because the scientific advice from ICES has been implemented more strictly during the last years, the status of many European fish stocks could be improved.
A deep understanding of the demography and dynamics of fish stocks is essential, enabling us to describe and predict the development of fish stocks. Whilst in the past fish stocks were often analyzed detached from their environment we spend more effort today to integrate climate effects and other environmental factors as well as complex predator-prey relationships into our stock assessment and forecast models. These ecosystem oriented models that we develop along with our colleagues from ICES form the basis for an ecosystem approach to fisheries management. As these data cannot always be collected by conventional sampling procedures we cooperate with other working groups of our institute to develop new monitoring methods for marine fish stocks and ecosystems.