An ecotoxicological analysis of the sediment quality in a European Atlantic harbor emphasizes the current limitations of the Water Framework Directive

The “PortoNovo” project was developed to standardize the methodologies for water quality management in the port areas of coastal Atlantic regions to improve the Water Frame Directive (WFD) for these specific water bodies. Under this scope, water and sediment samples were collected from five sites within the Port of Aveiro, Portugal. According to the physical and chemical parameters that were analyzed (i.e., metals, total organic carbon, polychlorinated biphenyls and polycyclic aromatic hydrocarbons), the sediments were not considered at risk based on European sediment quality laws. However, the bioassays that were performed on the sediment samples (Microtox®) and the standardized acute toxicity test using the marine rotifer, Brachionus plicatilis, on sediment elutriates revealed higher toxicity levels. The use of bioassays to assess sediment quality clearly complements more conservative approaches and highlights current gaps within the WFD. The approach presented here can be easily transferred to other port areas for more reliable water quality management.