Metal Ions on Selected Organisms

Theoretical generalization is not enough to evaluate the availability of metals to benthic fauna. In actual fact, the rate of uptake of any element and the extent of its retention in an organism are dependent on a number of ill-defined factors. As the data in Table 6 indicate, the extent of biological enrichment varies considerably between species. It is likely governed by  

1) the particular metal involved and its physiological importance to the organism, 

2) the physical and chemical state of the element and its availability to a specific organism, 

3) the concentration of the elements in the environment and the presence of other elements that may inhibit or enhance its uptake. The accumulation of one heavy metal by an organism may be altered by the relative abundance of another in the environment in one of three ways  

As a result of the interaction of these many factors, it is difficult to forecast the extent to which any heavy metal may be concentrated in a given organism. This section will therefore treat three widely differing examples the copper-algae interaction, metal ions and bivalves, and vanadium uptake by tunicates. 

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