The thematic report no. 6 on Eutrophication as part of the Quality Status Report 2009 (QSR 2009) provides an overview of the present status of human induced nutrient input into the Wadden Sea, based on the Trilateral Monitoring and Assessment Program (TMAP). This status review describes ecological targets, eutrophication effects and trends and developments.

From the QSR 2009, thematic report 6, Eutrophication:

Eutrophication is one of the factors that influences the quality of the Wadden Sea area. Since the earliest nutrient measurements in the Wadden Sea (Postma, 1954; Postma, 1966; Hickel, 1989) a clear increase in nutrient concentrations has been documented ( Jonge and Postma, 1974; Hickel, 1989; van Beusekom et al., 2001). Among the negative effects associated with the increased nutrient loads are Phaeocystis blooms (Lancelot et al., 1987), a decline in seagrass (de Jonge and de Jong, 1992), increased blooms of green macroalgae (Reise and Siebert, 1994) and anoxic sediments (Black Spots; de Jong et al., 1999a). Recently, decreasing riverine nutrient loads and decreasing phytoplankton standing stock have been observed in the Wadden Sea (Cadée and Hegeman, 2002; van Beusekom et al., 2009). A trilateral target was adopted to aim for ”A Wadden Sea which can be regarded as a eutrophication non problem area“. The concept of the eutrophication problem and non-problem areas was introduced in the framework of OSPAR (1997). The following sections summarize the findings of the last QSR (Essink et al., 2005), and the results of the OSPAR Common Procedure in 2008. In the chapter Data Analysis, recent trends in nutrient loads, nutrient concentrations and in phytoplankton and macroalgae biomass are described. A target evaluation and recommendations are given. The present report updates and extends the data analysis of the QSR 2005 (Essink et al., 2005). [….read more]

Quality Status Report 2009: Thematic Report No. 6: Eutrophication (v. Beusekom et al.)
Quality Status Report 2004: Chapter 5: Eutrophication: (v. Beusekom et al.)