Tidal Area

The overall theme Tidal Area covers various habitats and organisms groups occurring in the most prominent area of the Wadden Sea. In the Quality Status Report 2017 (QSR 2009) several thematic reports provide information on the status of habitats, organisms and processes in the Wadden Sea, based on the Trilateral Monitoring and Assessment Program (TMAP).

From the QSR 2017, thematic report on beds of blue mussels and Pacific oysters:

In the northern hemisphere, three taxa of blue mussels (Mytilus edulis complex) occur along the coasts of the North Atlantic and North Pacific. On the soft sediments in the Wadden Sea individual blue mussels aggregate and form beds (Figure 1). Pacific oysters (Crassostrea gigas) were introduced to several locations along the North Sea coast within NW Europe for aquaculture purposes in the 1960s and to the western Dutch Wadden Sea in the late 1970s (Troost, 2010) (see report "Alien species"). Wild Pacific oysters were first observed in the western Dutch Wadden Sea near Texel in 1983 (Fey et al., 2010; Troost, 2010). Pacific oysters naturally spread eastwards reaching the central Wadden Sea in 1998 (Wehrmann et al., 2000). Oysters were introduced in the northern Wadden Sea in the 1970s and the first Pacific oyster outside culture plots was observed in 1991 (Reise, 1998). Pacific oysters need hard substrates for larval settlement and shortly after their introduction they were found on shells of blue mussels. Mussels also colonize oyster beds (Troost et al., 2012; Van Stralen et al., 2012); mussels and Pacific oysters may co-exist in mixed beds with compositions ranging from almost 100 % blue mussels to almost 100 % Pacific oysters. Dense oyster beds are reef-like structures that often contain blue mussels (Kochmann et al., 2008; Markert et al., 2010; Figures 2 and 3). [….read more]

Quality Status Report 2017, thematic reports:

Geomorphology  (Oost et al.)
Macrozoobenthos (Drent et al.)
Beds of blue mussel and Pacific oyster  (Folmer et al.)
Seagrass (Dolch et al.)
Subtidal habitats (Vorberg et al.)

Quality Status Report 2009, thematic reports:

9          Geomorphology  (Wiersma et al.)
10        Macrozoobenthos (Graaf et al.)
11        Beds of Blue Mussel and Pacific Oyster  (Nehls et al.)
12        Seagrass (Graaf et al.)
13        Subtidal Habitats (Vorberg et al.)

Quality Status Report 2004, Chapter 8: Tidal Area:

8.1 & 8.2         Hydrology/Geomorphology & Macrozoobenthos (Essink)
8.3                   Intertidal Blue Mussel Beds (de Vlas et al.)
8.4                   Seagrass (Reise et al.)
8.5.1 & 8.5.2   Subtidal: Sabellaria - Subtidal Mussel Beds (Vorberg) & (de Vlas et al.)