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Southern Ocean iron fertilization by baleen whales and Antarctic krill
Citation
Nicol, S and Bowie, AR and Jarman, S and Lannuzel, D and Meiners, K and van der Merwe, P, Southern Ocean iron fertilization by baleen whales and Antarctic krill, Fish and Fisheries, 11, (2) pp. 203-209. ISSN 1467-2960 (2010) [Refereed Article]
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Copyright Statement
The definitive published version is available online at: http://onlinelibrary.wiley.com/
DOI: doi:10.1111/j.1467-2979.2010.00356.x
Abstract
Iron is the limiting micronutrient in the Southern Ocean and experiments have
demonstrated that addition of soluble iron to surface waters results in phytoplankton
blooms, particularly by large diatoms. Antarctic krill (Euphausia superba) eat diatoms
and recycle iron in surface waters when feeding. Baleen whales eat krill, and,
historically, defecation by baleen whales could have been a major mechanism for
recycling iron, if whale faeces contain significant quantities of iron. We analysed the
iron content in 27 samples of faeces from four species of baleen whale. Faecal iron
content (145.9 ± 133.7 mg kg)1) is approximately ten million times that of
Antarctic seawater, suggesting that it could act as a fertilizer. Furthermore, we
analysed the iron content of seven krill species and of muscle tissue of two species of
baleen whales; all samples had high iron levels. Using these figures, together with
recent estimates of the range and biomass of krill, we calculate that the Antarctic krill
population contains 24% of the total iron in the surface waters in its range. Thus,
krill can act as a long-term reservoir of iron in Antarctic surface waters, by storing
the iron in their body tissue. Pre-exploitation populations of whales and krill must
have stored larger quantities of iron and would have also recycled more iron in
surface waters, enhancing overall ocean productivity through a positive feedback
loop. Thus, allowing the great whales to recover might actually increase Southern
Ocean productivity through enhancing iron levels in the surface layer.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | Baleen whales, iron fertilization, krill, Southern Ocean |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Biological Oceanography |
| Objective Division: | Environment |
| Objective Group: | Ecosystem Assessment and Management |
| Objective Field: | Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments |
| UTAS Author: | Nicol, S (Dr Stephen Nicol) |
| UTAS Author: | Bowie, AR (Associate Professor Andrew Bowie) |
| UTAS Author: | Lannuzel, D (Associate Professor Delphine Lannuzel) |
| UTAS Author: | Meiners, K (Dr Klaus Meiners) |
| UTAS Author: | van der Merwe, P (Dr Pier van der Merwe) |
| ID Code: | 67556 |
| Year Published: | 2010 |
| Web of Science® Times Cited: | 77 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2011-03-04 |
| Last Modified: | 2011-10-06 |
| Downloads: | 0 |
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