Coastal and marine ecosystems are under pressure from various human activities, which exert direct and indirect impacts on underwater biota. To apply relevant management policies on human activities, detailed information on ecological impacts of the activities is urgently needed. Ecological systems are often subject to non-linear dynamics and change points, where an external pressure may lead to abrupt changes in community composition. This poses a challenge for sustainable management of human activities. The European environmental legislation and HELCOM policy objectives aim at environmentally sustainable levels of human activities and uses, which enable good environmental status of the marine environment.
While eutrophication remains the main impact factor on the Nordic coastal areas and the Baltic Sea, other human pressures, such as bottom trawling, dredging, shipping, boating and costal land use have significant effects on underwater flora and fauna. Many of these types of pressures typically occur in coastal waters which also host more diverse and productive underwater wildlife than offshore areas.
In the COMA project (Cumulative pressure and impact studies supporting marine management and assessment), the impacts of human activities and pressures on marine ecosystem were analysed from three different viewpoints: (1) What is the evidence of ecosystem responses to single and multiple pressures? (2) How do different human activities impact the marine ecosystem? and (3) What is the evidence of sustainable levels of human activities? These objectives are supported by quantitative analyses and reviews of existing studies in the region.
The ultimate goal of this report is to provide guidance for marine management. It provides evidence of the most impacting activities on marine environment and supports managers in evaluating the impacts of these activities.