The significance of pre- and post-restoration studies in lake therapy

摘要

Questionnaires and a literature study reveal that the effects of lake restoration are often less than expected and that often no or insufficient pre- and post-restoration studies are conducted in Germany. However, thorough investigation of lakes andcatchment areas is necessary: to identify problems and causes, to define success criteria, to choose the most suitable strategy to achieve the set goal, to supervise and optimize restoration and to determine whether restoration was successful. Pre-restoration investigations increase the propability of success. We show that investigation, though expensive, can reduce the costs of lake restoration and increase the cost/benefit relation. Post-restoration investigations increase knowledge for application tofuture lake therapies. Results, including failures, should be published in readily available reports or journals. The investigations should be carried out or evaluated by neutral parties not involved in the restoration efforts.