Southern Ocean natural iron fertilization Introduction

TitleSouthern Ocean natural iron fertilization Introduction
Publication TypeJournal Article
Year of Publication2013
AuthorsCharette MA, Gille ST, Sanders R.J, Zhou M.
JournalDeep-Sea Research Part Ii-Topical Studies in Oceanography
Date Published2013/06
Type of ArticleEditorial Material
ISBN Number0967-0645
Accession NumberWOS:000320142000001
Keywordsphytoplankton bloom

he surface waters of the Southern Ocean have been widely identified as being replete in macronutrients (nitrogen and phosphorous) that phytoplankton appear unable to use. This makes the Southern Ocean the largest high nutrient low chlorophyll (HNLC) region in the global ocean (e.g. Chisholm and Morel, 1991).Martin (1992) hypothesized that inadequate supplies of iron (Fe) were responsible for HNLC conditions.

John Martin famously joked, “Give me a half tanker of iron, and I will give you an ice age,” suggesting that the addition of iron might stimulate sufficient phytoplankton growth to result in net oceanic uptake of carbon dioxide. Martin's hypothesis motivated a number of field programs that tested how the ocean would respond to artificial addition of iron (de Baar et al., 2005). These included, for example, the Southern Ocean Iron Release Experiment (SOIREE, e.g. Abraham et al., 2000 and Boyd et al., 2000) and Southern Ocean Iron Fertilization Experiment (SOFEX, e.g. Coale et al. 2004). Collectively these field experiments showed that iron addition led to immediate localized phytoplankton blooms. They also have stimulated considerable speculation casting doubt on the potential for geoengineering climate via iron fertilization (e.g. Zeebe and Archer, 2005).

However, perhaps the more intriguing question is why some parts of the Southern Ocean appear to have sufficient iron available to support strong biological blooms. Interest in the underlying processes motivated three field programs in 2004–2006.