Nieuws - 6 november 2008


According to Natuurbalans 2008, the North Sea is like a patient who seems to be getting better, but who is still far from healthy. Per drs. John Schobben, the environmental division chief at the Imares in Wageningen, this is due to the poor manner in which the patient has been examined.

Last summer the proposed guidelines for a European marine strategy came into force. Their purpose is to determine a standard for the maintenance and restoration of the European seas, including the North Sea, with the aim of getting them in ‘ a good environmental state of affairs’. The Netherlands is required to set out their contribution to this effort before 2010. Schobben is making the case that we should be investigating a broad range of polluting substances. He finds the guideline’s so-called priorities nightmarishly inadequate for conducting a meaningful investigation of the pollutants to be found in the inland waterways of the North Sea.

He warns that there are a myriad number of substances to be found there which are damaging to the marine environment. Take, for example, the minor attention that has been given to perfluoro compounds, chemicals which make textiles water-repellent, even though they has already been detected in porpoises in very high concentrations. Another example is igarol, a relatively new substance that retards algal growth on boat paint. ‘The Dutch Ministry of Public Works anticipates an increase of this substance in the Wadden Sea, while in Dutch harbors this increase is already a fact of life. Irgarol is the successor to tributylin which has since been banned worldwide.

According to Schobben there are many more substances that could possibly be dangerous. ‘By implementing a new method, we have already shown that there are at least four hundred substances in the sediment of the North Sea. Naturally, the one asks which substance causes which effect and what is the said effect. I must say, this begs the question: Is the North Sea a clean body of water?’.

Above everything else, Schobben is critical of the EU’s prescribed manner for measuring pollutants. Generally speaking, there are pollutants that can be measured in the water bottom, in the animals themselves and in the water’s suspended particulate matter. ‘The EU says that you must make a measurement based on a litre of water and that you need not measure further. The particulate concentrations there are so small that they will not show up by measuring just one litre. Indeed, it might seem that the pollution problem will already been solved; however, that would be sticking one’s head in the sand. Many of these substances are fat-soluble and they make their way into mussels and fish where the concentration of these substances is measurably high.

Schobben’s view is that researchers must not only check the quality of the water, but they should also investigate the effects of pollutants on animal life. A recent measurement taken by Imares of the current pcb concentration in Dutch coastal waters shows a threat to sole larvae and illustrates the importance of this step. The institute has devoted much energy to developing tests for measuring just such effects on fish and other sea animals. According to Schobben, the North Sea patient deserves to be examined by a good doctor. ‘If you visit the doctor and he says ‘I find no fever, you are fully healthy’, is this necessarily the case? Musn’t the physician also take your blood pressure and have a look at your choleste¬rol numbers? The same can be said for the North Sea. We need to devise a ther¬mo¬meter that is so comprehensive that we can really say: the sea is healthy.’