Author / Editor: Marta Revilla, Javier Franco, Maialen Garmendia and Ángel Borja (AZTI-Tecnalia)
Content: Since 2002, a modified method from Ifremer has been applied to the Basque estuaries for phytoplankton quality assessment, within the context of the European Water Framework Directive (WFD). This method has built upon a tool for the Shellfish Waters Directive, presenting some limitations for the WFD; the latter is focused upon ecological quality, with the former on human health. In 2009, during the second phase of the WFD intercalibration, a new method was agreed for transitional waters in northern Spain, between experts from the regional governments of the Asturias, Cantabria and the Basque Country. The present study compares the previously-applied method, with the new method, in the estuaries of the Basque Country. It checks the consistency of both methods with eutrophication risk of these marine systems evaluated by expert judgment and historical data analysis.