Biogeochemistry of trace metals in the ocean

A variety of metallic elements, particularly Fe and Zn, are considered essential for biological processes in a variety of natural ecosystems, but are generally present only in trace amounts. Although their essential nature in terrestrial ecosystems has been known for many decades, it is only in recent years that scientific methodology has improved to the point that the biogeochemical behaviour of trace metals can be adequately studied in aquatic ecosystems such as the ocean. This paper reviews some of the recent scientific progress and demonstrates how conventional thinking about the biogeochemical role of trace metals in the ocean has been advanced by the findings of this research. In particular, it is now clear that the availability of several trace elements is a factor that controls phytoplankton growth in the ocean.