The WFD implementation set limits for contaminant discharges into aquatic ecosystems. Therefore, current contamination events result mainly from geochemical processes involving contaminants stored in sediments. These processes result in the loss of ecosystem services, such as the loss of recreational value in impacted areas, reduced biodiversity, fish and other food and feed resources contamination, and health effects. The WFD imposes rehabilitation measures for water bodies with poor chemical status, highlighting the need to develop remediation strategies for these historically contaminated ecosystems.
The worldwide decline of seagrass communities has originated the development of numerous seagrass recovery programs. It is well established that seagrass meadows enhance biodiversity and biological production over bare bottom sediments and retain and stabilise the sediment by reducing currents and wave re-suspension. In addition, seagrasses have been considered moderately tolerant to anthropogenic contamination, which highlights their potential as remediation agents.
The main goal of the project will therefore be to test a remediation strategy for historically contaminated estuarine sites, through the re-colonization with seagrasses.
The pilot program will take place in a restricted area of the Ria de Aveiro with historical mercury and arsenic contamination records, and previously covered by seagrasses.