Iron is delivered to the open ocean mainly by rivers, aeolian dust, icebergs (and subglacial runoff), hydrothermal activity and by recycling from shelf sediments (Fig. 1.5). It is believed that only rivers and hydrothermal activity supply iron in a dissolved form but neither source is effective at reaching surface waters in the open ocean. Most dissolved iron in rivers is removed in estuaries and most dissolved iron in hydrothermal sources is supplied to deep waters (Section 7). However iron is an essential nutrient for the growth of marine plankton in surface waters and, in some regions of the...

First Page Preview

First page PDF preview
You do not currently have access to this article.