eCite Digital Repository

Regulation of algal blooms in Antarctic shelf waters by the release of iron from melting sea ice


Sedwick, PN and DiTullio, GR, Regulation of algal blooms in Antarctic shelf waters by the release of iron from melting sea ice, Geophysical Research Letters, 24, (20) pp. 2515-2518. ISSN 0094-8276 (1997) [Refereed Article]

DOI: doi:10.1029/97GL02596


During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30′S, 170°40′W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied by a significant drawdown in macronutrients and an approximate doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were ironreplete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise that bioavailable iron was released into seawater from the melting sea ice, stimulating phytoplankton production and the biological removal of dissolved iron from the mixed layer, until iron-limited conditions developed. These observations suggest that the episodic release of bioavailable iron from melting sea ice is an important factor regulating phytoplankton production, particularly ice-edge blooms, in seasonally ice-covered Antarctic waters. Copyright 1997 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)
ID Code:12658
Year Published:1997
Web of Science® Times Cited:270
Deposited By:IASOS
Deposited On:1997-08-01
Last Modified:2011-08-15

Repository Staff Only: item control page