Dissolution of atmospheric iron in seawater

Bonnet, Sophie

doi:10.1029/2003gl018423

Cited by 127 publications

(146 citation statements)

References 26 publications

(29 reference statements)

Supporting

Mentioning

122

Contrasting

Unclassified

Order By: Relevance

“…Our numbers are in agreement with previous studies by Bonnet and Guieu [2004] and Mendez et al [2008] conducted with the same dust.…”

Section: Atmospheric Iron Dissolutionsupporting

confidence: 93%

“…Between filtrations, the two containers were placed on a shaker (frequency: 1 s À1 ). It has to be mentioned that the final dust concentration used in this experiment is higher than that expected in the surface mixed layer after most typical-intensity Saharan events in the Mediterranean Sea (see range proposed by Bonnet and Guieu [2004]). …”

Section: Dissolution Experimentsmentioning

confidence: 75%

See 1 more Smart Citation

Dust iron dissolution in seawater: Results from a one‐year time‐series in the Mediterranean Sea

Wagener¹,

Pulido-Villena²,

Guieu³

2008

Geophysical Research Letters

View full text Add to dashboard Cite

[1] A better comprehension of atmospheric iron dissolution in seawater would be a key advance in understanding the atmospheric supply of iron to the ocean and its role on marine biogeochemistry. So far, different studies have demonstrated that dissolution of atmospheric iron depends on physical and chemical properties of the particles, which can be modified during their transport from the source. Here, based on a one-year time-series in the Western Mediterranean Sea, we show that dissolution of iron from a Saharan desert dust sample in seawater follows the seasonal trend of the dissolved organic carbon (DOC) variability in the surface layer. As part of the DOC pool, the role of iron binding ligands, probably derived from bacteria activity, has also been investigated. The dust iron dissolution rates are found to be linearly dependent on iron binding ligands and dissolved organic carbon concentrations (r 2 > 0.65, p < 0.01, n = 9).

show abstract

“…Our numbers are in agreement with previous studies by Bonnet and Guieu [2004] and Mendez et al [2008] conducted with the same dust.…”

Section: Atmospheric Iron Dissolutionsupporting

confidence: 93%

Section: Dissolution Experimentsmentioning

confidence: 75%

Dust iron dissolution in seawater: Results from a one‐year time‐series in the Mediterranean Sea

Wagener¹,

Pulido-Villena²,

Guieu³

2008

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…An increase in UCYN-A abundance in response to dust has been observed in a comparable experiment in the Atlantic, although the authors did not see a change in abundance in their Fe treatment (Langlois et al, 2012). The deposition of dust in the marine environment may also release P in addition to Fe (Ridame and Guieu, 2002;Bonnet and Guieu, 2004). We could not determine the effect of P alone on the N 2 fixation rates by UCYN-A because of the lack of associations in that treatment, but our results from the PFe treatment indicated elevated N 2 fixation by UCYN-A relative to the control.…”

Section: Discussionmentioning

confidence: 82%

The effect of nutrients on carbon and nitrogen fixation by the UCYN-A–haptophyte symbiosis

et al. 2014

View full text Add to dashboard Cite

Symbiotic relationships between phytoplankton and N 2 -fixing microorganisms play a crucial role in marine ecosystems. The abundant and widespread unicellular cyanobacteria group A (UCYN-A) has recently been found to live symbiotically with a haptophyte. Here, we investigated the effect of nitrogen (N), phosphorus (P), iron (Fe) and Saharan dust additions on nitrogen (N 2 ) fixation and primary production by the UCYN-A-haptophyte association in the subtropical eastern North Atlantic Ocean using nifH expression analysis and stable isotope incubations combined with single-cell measurements. N 2 fixation by UCYN-A was stimulated by the addition of Fe and Saharan dust, although this was not reflected in the nifH expression. CO 2 fixation by the haptophyte was stimulated by the addition of ammonium nitrate as well as Fe and Saharan dust. Intriguingly, the single-cell analysis using nanometer scale secondary ion mass spectrometry indicates that the increased CO 2 fixation by the haptophyte in treatments without added fixed N is likely an indirect result of the positive effect of Fe and/or P on UCYN-A N 2 fixation and the transfer of N 2 -derived N to the haptophyte. Our results reveal a direct linkage between the marine carbon and nitrogen cycles that is fuelled by the atmospheric deposition of dust. The comparison of single-cell rates suggests a tight coupling of nitrogen and carbon transfer that stays balanced even under changing nutrient regimes. However, it appears that the transfer of carbon from the haptophyte to UCYN-A requires a transfer of nitrogen from UCYN-A. This tight coupling indicates an obligate symbiosis of this globally important diazotrophic association.

show abstract

“…This absence of response can be interpreted by the fact that only 0.1% of the iron in the dust dissolved, which is ten times lower than the dissolution found with the same amount of the same dust in the Mediterranean waters by Bonnet and Guieu (2004). This difference can be interpreted by the difference in organic ligands concentrations between the Pacific and the Mediterranean waters (Bonnet, 2005).…”

Section: The Role Of Fementioning

confidence: 90%

Nutrient limitation of primary productivity in the Southeast Pacific (BIOSOPE cruise)

et al. 2008

View full text Add to dashboard Cite

Abstract.Iron is an essential nutrient involved in a variety of biological processes in the ocean, including photosynthesis, respiration and dinitrogen fixation. Atmospheric deposition of aerosols is recognized as the main source of iron for the surface ocean. In high nutrient, low chlorophyll areas, it is now clearly established that iron limits phytoplankton productivity but its biogeochemical role in low nutrient, low chlorophyll environments has been poorly studied. We investigated this question in the unexplored southeast Pacific, arguably the most oligotrophic area of the global ocean. Situated far from any continental aerosol source, the atmospheric iron flux to this province is amongst the lowest of the world ocean. Here we report that, despite low dissolved iron concentrations (∼0.1 nmol l −1 ) across the whole gyre (3 stations located in the center and at the western and the eastern edges), primary productivity are only limited by iron availability at the border of the gyre, but not in the center. The seasonal stability of the gyre has apparently allowed for the development of populations acclimated to these extreme oligotrophic conditions. Moreover, despite clear evidence of nitrogen limitation in the central gyre, we were unable to measure dinitrogen fixation in our experiments, even after iron and/or phosphate additions, and cyanobacterial nif H gene abundances were extremely low compared to the North Pacific Gyre. The South Pacific gyre is therefore unique with respect to the physiological status of its phytoplankton populations.

show abstract

Dissolution of atmospheric iron in seawater

Cited by 127 publications

References 26 publications

Dust iron dissolution in seawater: Results from a one‐year time‐series in the Mediterranean Sea

Dust iron dissolution in seawater: Results from a one‐year time‐series in the Mediterranean Sea

The effect of nutrients on carbon and nitrogen fixation by the UCYN-A–haptophyte symbiosis

Nutrient limitation of primary productivity in the Southeast Pacific (BIOSOPE cruise)

Contact Info

Product

Resources

About