IMIS

Most transects were situated perpendicular to the direction of the tidal channels. Most attention (380 stations) was paid to the area between MLTL and MLTL – 4 m. 35 stations were located within mussel lots. Sampling was done with a 0.2 m2 van Veen grab and a 0.02 m2 flushing sampler modified for subtidal sampling from a large vessel. At most station, 3 samples with the flushing sampler and one Van Veen-grab sample were taken. In 2008, these transects were revisited in the framwork of the PRODUS project. Since 1989, three subtidal transects are sampled in late winter (February-March) and late summer (August-September) with a 0.06 m2 Reineck box-corer up to 45 cm in depth (min. 15 cm). At each transects of 1500 m 15 samples are collected. From each of these cores a subsample (core diameter 4.25 cm, depth 4 cm) is taken for Hydrobia ulvae.