According to the EU Water Framework Directive, all surface waters should reach a good ecological status by 2015. While it seems realistic to achieve this objective for the river Oder/Odra itself, the water quality of the Szczecin (Oder-) Lagoon cannot be sufficiently improved through river basin management alone. Therefore, supporting internal measures must be considered. The zebra mussel, Dreissena polymorpha, a species currently inhabiting the whole lagoon, has a high filtration potential. With filtration rates of 3000-4000 l m-² d-1 Dreissena could potentially improve water quality, especially water transparency, which is a key factor for beneficial regional tourism development. Cultivation of mussels, combined with systematic harvest could help to reduce the nutrient content in the Szczecin Lagoon. This article presents the results of a literature-based suitability analysis for cultivating Dreissena polymorpha in the lagoon. Besides ecological and filtration effects, economic utilization of Dreissena is discussed to assess costs and benefits of mussel aquaculture. The results show that selling Dreissena is difficult. Therefore, economic benefits of cultivation are limited. Further financing strategies could be a tourism fee for water quality improvement or nutrient emission certificates.