Biogeochemistry of trace metals in the ocean

A variety of metallic elements, particularly Fe and Zn, are considered esse ntial 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 rece nt years that scientific methodology has improved to the point that the bio geochemical behaviour of trace metals can be adequately studied in aquatic ecosystems such as the ocean. This paper reviews some of the recent scienti fic progress and demonstrates how conventional thinking about the biogeoche mical role of trace metals in the ocean has been advanced by the findings o f this research. In particular, it is now clear that the availability of se veral trace elements is a factor that controls phytoplankton growth in the ocean.