2.1. Sampling
From 2007 to 2012, a total of 2296 samples of bivalve molluscs
were taken along the Norwegian coast. The examined material
comprise mainly bivalves, including 2055 samples of blue mussels
(M. edulis) from 152 localities (Fig. 1.), 106 samples of oysters
(O. edulis), 100 samples of scallops (P. maximus), 21 samples of
cockles (C. edule) and 14 samples of horse mussels (M. modiolus).
Each sample comprised at least 10 individuals. Samples were
transported under chilled conditions to the laboratory and the
analyses were initiated within 24 h after sampling.