Frequency Distribution of Zinc Concentrations in the Common Mussel, Mytilus edulis (L)

Abstract
The frequency distribution of zinc concentrations in a population of mussels (Mytilus edulis) from the moderately polluted Tyne estuary showed marked positive skewness. A peak was reached between 3 and 4 μmoles per dry gram of whole soft tissue followed by a long tail ending with a single exceptional value of 20.5 μmoles per g. The mean zinc concentration for the population was 5.13±2.66 (standard deviation). The skewness (g1) value was 1.78 (SE+0.14 p≪0.001). Within the population, there was a strong positive association between the log mean zinc concentration of a single collection and the log variance of the collection. The significance of this for biomonitoring procedures is discussed.