(such as copper, nickel, lead, zinc and cadmium ) by
seaweeds became apparent when those seaweeds used as human foods were first analysed.
The heavy metal content, especially of the large brown seaweeds, varied according to their
geographic source and sometimes to their proximity to industrial waste outlets. From these
studies came the idea of using seaweeds as biological indicators of heavy metal pollution,
either from natural sources or from activities such as mining or disposal of industrial
wastes. This has been successfully implemented using brown seaweeds such as Sargassum,
Laminaria and Ecklonia, and the green seaweeds Ulva and Enteromorpha