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Limitation of algal growth by iron deficiency in the Australian Subantarctic region


Sedwick, PN and DiTullio, GR and Hutchins, DA and Boyd, PW and Griffiths, FB and Crossley, AC and Trull, T and Queguiner, B, Limitation of algal growth by iron deficiency in the Australian Subantarctic region, Geophysical Research Letters, 26, (18) pp. 2865-2868. ISSN 0094-8276 (1999) [Refereed Article]

DOI: doi:10.1029/1998GL002284


In March 1998 we measured iron in the upper water column and conducted iron- and nutrient-enrichment bottle-incubation experiments in the open-ocean Subantarctic region southwest of Tasmania, Australia. In the Subtropical Convergence Zone (∼42°S, 142°E), silicic acid concentrations were low (< 1.5 μM) in the upper water column, whereas pronounced vertical gradients in dissolved iron concentration (0.12-0.84 nM) were observed, presumably reflecting the interleaving of Subtropical and Subantarctic waters, and mineral aerosol input. Results of a bottle-incubation experiment performed at this location indicate that phytoplankton growth rates were limited by iron deficiency within the iron-poor layer of the euphotic zone. In the Subantarctic water mass (∼46.8°S, 142°E), low concentrations of dissolved iron (0.05-0.11 nM) and silicic acid (< 1 μM) were measured throughout the upper water column, and our experimental results indicate that algal growth was limited by iron deficiency. These observations suggest that availability of dissolved iron is a primary factor limiting phytoplankton growth over much of the Subantarctic Southern Ocean in the late summer and autumn. Copyright 1999 by the American Geophysical Union.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Oceanic processes (excl. in the Antarctic and Southern Ocean)
UTAS Author:Sedwick, PN (Dr Peter Sedwick)
UTAS Author:Crossley, AC (Dr Clive Crossley)
UTAS Author:Trull, T (Professor Thomas Trull)
ID Code:17093
Year Published:1999
Web of Science® Times Cited:97
Deposited By:IASOS
Deposited On:1999-08-01
Last Modified:2000-05-20

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