This study is the first component of the ëResearch on the environmental effects of the SIGMA plan: Effects of dredgings and harbour expansion on the environmentí It provides the basis of a dataset which can be used for several aims (modeling, research contexts,Ö.). The coordination of all themeís is constructed in such a way that the homogeneity of the common dataset is not liable to be pushed aside. Within this study a recognition of the Flemish government and accreditation according to EN 45001 or ISO/IEC 17025 is necessary for all the parameters that are not measured in situ: hydrochlorate, sulfaat, OFFER, ammonium, nitrite, nitrate, kjeldahl nitrogen, orthophosphate, total phosphorus and dissolved silicon. All samples analyzed in the laboratory were kept cool and in the dark.