Shell characteristics, isotopic composition and trace-element contents of some euryhaline molluscs as indicators of salinity
The shell characteristics, δ13C−δ18 and trace-element contents of five euryhaline molluscs from the Dutch coastal waters are considered in relation to salinity. Shape and weight of the shells may be influenced by salinity but are too variable to show a significant correlation. Maximum size and maximum age decrease with salinity. Between δ13C−δ18O and salinity there is a strong correlation allowing salinity to be determined within 0.5‰ Cl′. Also the average number of ribs on Cardium edule shell is strongly related to salinity, which can be determined from the average rib number within ±1.5‰Cl′. The results on the relation between trace-element contents and salinity are contradictory. The various relationships with salinity are not clear and need further elucidation.