Table 4 Number and estimated DNA copy number of bivalve and decapod crustacean larvae in the five sampling sites (five field replicate per site) using direct (microscopy) and indirect (genetic) methods. *: presented as the sum of estimated DNA copies/µl over all positive assays. #: values displayed forCarcinus maenas COI assay only, as it was the only decapod species that amplified. Significant groups (A-B) and values (>0.05-0.005*, >0.0005***) obtained using a Tukey-test.