Abstract
We compared the importance of Fe, Zn and Si availability for diatom growth and silicification through microcosm enrichment experiments in two contrasting HNLC systems of the Sub-Arctic and Sub-Antarctic Pacific. The Bering Sea was characterized by low Fe and Zn concentrations (Pseudo-nitzschiasp. and Cylindrotheca closterium ), an increase in Chl a , biogenic silica, and particulate organic carbon and nitrogen, and a 2–3-fold decrease in the average cellular Si content. Zn had no impact on biomass parameters or diatom community structure in this region.
The Sub-Antarctic Zone (SAZ) was a low Si-HNLC system, with initial silicic acid levels of 0.45 μM and Fe and Zn concentrations Pseudo-nitzschiasp.) towards a smaller and less silicified solitary pennate ( Cylindrotheca closterium ), potentially prone to more rapid silica dissolution in the surface layer.
Despite the dominance by the same two diatom genera, these two high-latitude regimes exhibited different nutrient limitation scenarios. Diatom growth in the Bering Sea was strongly Fe-limited, while the SAZ was mainly limited by Si and only secondarily by Fe.
Original language | American English |
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Journal | Deep Sea Research Part I: Oceanographic Research Papers |
Volume | 52 |
DOIs | |
State | Published - Oct 1 2005 |
Keywords
- Iron
- Zinc
- Silicate
- Diatoms
- HNLC
- HNLSiLC
- Trace metal limitation
Disciplines
- Life Sciences