The development of aquaculture is a story of international success, but not in the EU. The present study investigates why the development of aquaculture is stalling or sometimes even follows a downward trend in some countries, using Germany as a case study. The EU framework for aquaculture policies has established a "twin logic" as a long-term strategy: Protection of the environment and economic growth. The present sociological approach uses qualitative data from group discussions with aquaculture stakeholders from industries, politics, regulation, environmental protection agencies, and NGOs. The stakeholders indicated that a small, fragmented sector without economic and political power on the one hand, and an overregulated, complex governance on the other hand are the main barriers to economic growth. Applying Parsons' Action Frame of Reference, the article argues that the German stakeholders are not able to adopt the EU twin logic as a clear solution for overcoming the stagnation of aquaculture in Germany in practice. For the stakeholders, the twin logic results in confusing framework conditions in terms of societal expectations, values, norms, regulations, and their national implementation. The uncertainty is rooted in diametrically societal values and leads to conflicts at the individual level of stakeholders' decision-making for investments. In consequence, the societal environment for aquaculture investment measures is uncertain. This exploration results in an empirical-grounded hypothesis, that aquaculture is a dysfunctional system of action.
