Integral Risk Analysis as a Supporting Framework for Water Quality Management

The prevention of pollution in a marine ecosystem such as the North Sea has traditionally been approached from two angles i.e. (1) by controlling the disturbance at source and (2) by monitoring the quality of the marine environment and act when deleterious effects occur. These approaches are loosely based on the precautionary principle and on the concept of assimilative capacity, respectively. Although in principle different approaches, they are similar in practice as they both accept, rightly or wrongly, a certain input of pollutants to the marine environment. There remains however, a stubborn lack of information as to what qualitative and quantitative relationship exists between the input(s)/sources and consequently the distrubance or effects in the marine environment. Environmental stress in a marine ecosystem becomes visible when the dynamics of its elements deviate from their normal cycles or fluctuations. These observable end-effects are often the initial reason for concern, i.e. long after the process of disturbance is underway. It has always been difficult to interpret these mostly complex signals and relate the observations to primary causes. In order to handle the diversity of information and signals in the cause-effect chain between input(s)/sources and disturbance, the development of a comprehensive logic framework is needed.