Monitoring the biotic aspects of our environment as a policy instrument.

As all environmental programs also programs monitoring the biotic aspects of our environment (dealt with in this article) should contribute to a more effective and efficient environmental policy. These programs have to function therefore (as no other type of environmental information does, according to the authors) as cheap and efficient 'early warning' and 'early control systems', providing decision makers with 'important' and reliable monitoring results.How these monitoring programs should function in the decision making process is illustrated in abstract in this article by a simple control system with feedback (as shown in Figures 1, 2 and 3).The monitoring programs dealt with in this article should enable us to detect and forecast changes in the most important biotic aspects of our environment and-by continuous monitoring-to control whether the use of policy instruments has been effective or not in averting or diminishing unwanted changes ('problems').Two options of decision makers with respect to monitoring results are shown (either to disregard unwanted changes as a problem or to accept these changes as a problem and to do something about them). To contribute to an effective and efficient environmental policy monitoring results therefore have to be 'important' and reliable enough to react upon.The question is raised which biotic aspects in our environment are (or have to be considered as) important (because of their own value, as indicators and/or as biotic 'conditions') and how reliable monitoring results can (have to) be obtained.It is discussed how environmentalists could try to make it more difficult for decision makers to duck the problems (by monitoring only important aspects and by using only perfectly clear targets and standards) and how they could try at the same time to make it easier for them to take action (by setting up integrated 'environmental monitoring programs' in order to find out how desired and undesired changes can be influenced). The role of active publicity is stressed in this connection.

The effect of the dumping of waste-acid from the titanium-dioxide production on the chlorophyl-a concentration of North Sea water: A time series analysis.

Since 1963 the waste-acid of the German titanium dioxide industry is discharged off the Dutch coast. From March 1980 on the dumping takes place in an area situated 40-80 km from the coast. Although about 2 500 000 kg waste-acid is discharged every day, until now no effects could be found on the plankton.This paper describes the study on the effects of the dumping on the chlorophyl-a concentration of the seawater at a site north of the dumping area, with the help of time series analysis. It is shown that considerable changes in the chlorophyl concentration occur during the dumping period and that these changes coincide with certain events within the dumping history. However, it is most remarkable that the starting of the dumping itself does not show an effect on the chlorophyl concentrations. Explanations are suggested, but could not be investigated yet.This study shows also that collecting data without a proper statistical design make it impossible to draw unambiguous conclusions based on those data.