Any surface exposed to untreated water provides an opportunity for the settlement and subsequent growth of organisms. The cooling water conduits of a power station provides an ideal habitat for such species. Given these perfect conditions, settlement occurs readily and growth can be rapid until it begins to interfere with the operational systems and finally leads to their failure. This phenomenon is known as bio-fouling. Worldwide, mussels cause serious problems in cooling water conduits. Because of the great economical damage, caused by these fouling-organisms, biocides are being used to control them. To use these chemicals properly, knowledge of the lifecycle of these organisms is indispensable and monitoring is necessary. Using the Scheldt water as cooling water, a lot of companies in the harbour of Antwerp have problems with fouling organisms. In this research, Mytilopsis leucophaeata , the brackish water mussel, will be used as modelspecies for the study of biofouling control. The problems and possible solutions will be examined at the site of BASF, Antwerp.The objective of the project is to achieve an efficient and rational use of biocides to control bio-fouling caused by M. leucophaeata and as such minimise their harm in the environment and in the cooling water conduits.This objective is divided in four aspects:1. Population dynamics of M. leucophaeata Weekly sampling of the incoming cooling water gives us a reliable view on the population dynamics of M. leucophaeata . 2. Development of an 'early warning system' Knowledge about the population dynamics of M. leucophaeata will be used to develop an 'early warning system' to use biocides at the right time (= the fouling organisms most vulnerable stage) and in the right dosage.3. Influencing environmental factors on the lifecycle of M. leucophaeata Experimental research will test the influences of the environmental parameters on the lifecycle, possibly simplifying the prediction of or reducting the recruitment success of M. leucophaeata .4. Prediction of the ...