scholarly journals Amazon River influence on nitrogen fixation and export production in the western tropical North Atlantic

2016 ◽  
Vol 62 (2) ◽  
pp. 618-631 ◽  
Author(s):  
Sarah C. Weber ◽  
Edward J. Carpenter ◽  
Victoria J. Coles ◽  
Patricia L. Yager ◽  
Joaquim Goes ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
North Atlantic ◽  
Amazon River ◽  
Export Production ◽  
Tropical North Atlantic

scholarly journals Influence of the Amazon River on dissolved and intra-cellular metal concentrations in <i>Trichodesmium</i> colonies along the western boundary of the sub-tropical North Atlantic Ocean

2011 ◽  
Vol 8 (1) ◽  
pp. 217-225 ◽  
Author(s):  
A. Tovar-Sanchez ◽  
S. A. Sañudo-Wilhelmy
Keyword(s):  
Nitrogen Fixation ◽  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Amazon River ◽  
Physical Parameters ◽  
Metal Concentrations ◽  
Field Samples ◽  
Metal Composition ◽  
The Impact

Abstract. Despite the ecological importance of Trichodesmium spp. for the global oceanic nitrogen budget, there is limited information on their trace metal composition in field samples. We report dissolved (<0.22 μm) metal concentrations measured in surface waters (Ag, Cd, Co, Cu, Fe, Mo, Ni, P, Pb and V) and in the total and the intracellular pool (Ag, Al, Cd, Co, Cu, Fe, Mn, Mo, Ni, P, Pb, V) of Trichodesmium populations collected in the western subtropical North Atlantic Ocean (April–May 2003) within the influence of the Amazon River plume. Dissolved element distributions were strongly influenced by the River discharge, with concentrations of some elements varying directly (i.e. Cd, Mo and V) or inversely (Ag, Co, Cu, Fe, Ni, P and Pb) with surface salinity. Intracellular metal values to phosphorous ratios (mol:mol) for Cd, Co, Cu, Fe, Mn, Mo, Ni and V ranged from 9.0 × 10−6 for Cd to 4.4 × 10−2 for Fe. Although total metal composition was significantly correlated with the intracellular content in the Trichodesmium colonies for some elements (e.g., Co, Cu, V), metal pools in the phytoplankton did not co-vary with the dissolved metal concentrations, suggesting that water column measurements may not be good predictors of the intracellular metal concentrations. The impact of physical parameters and bioactive elements on biological processes such as nitrogen fixation, carbon drawdown and biomass production in Trichodesmium colonies was explored by using a principal component analysis test (PCA). The analysis indicated that the biological drawdown of dissolved inorganic carbon (DIC) by Trichodesmium seems to be influenced by the internal content of Fe, Co, Cd, and Cu, while nitrogen fixation seems more influenced by mixed layer depth and dissolved Fe and Ni concentrations.

scholarly journals The pathways and properties of the Amazon River Plume in the tropical North Atlantic Ocean

2013 ◽  
Vol 118 (12) ◽  
pp. 6894-6913 ◽  
Author(s):  
Victoria J. Coles ◽  
Maureen T. Brooks ◽  
Julia Hopkins ◽  
Michael R. Stukel ◽  
Patricia L. Yager ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
River Plume ◽  
Amazon River ◽  
Tropical North Atlantic ◽  
Amazon River Plume

scholarly journals The distribution of thiamin and pyridoxine in the western tropical North Atlantic Amazon River plume

2013 ◽  
Vol 4 ◽  
Author(s):  
Laila P. Barada ◽  
Lynda Cutter ◽  
Joseph P. Montoya ◽  
Eric A. Webb ◽  
Douglas G. Capone ◽  
...  
Keyword(s):  
North Atlantic ◽  
River Plume ◽  
Amazon River ◽  
Tropical North Atlantic ◽  
Amazon River Plume

scholarly journals Meso- and microzooplankton grazing in the Amazon River plume and western tropical North Atlantic

2016 ◽  
Vol 61 (3) ◽  
pp. 825-840 ◽  
Author(s):  
Brandon J. Conroy ◽  
Deborah K. Steinberg ◽  
Michael R. Stukel ◽  
Joaquim I. Goes ◽  
Victoria J. Coles
Keyword(s):  
North Atlantic ◽  
River Plume ◽  
Amazon River ◽  
Tropical North Atlantic ◽  
Amazon River Plume ◽  
Microzooplankton Grazing

scholarly journals Influence of the Amazon River discharge on the biogeography of phytoplankton communities in the western tropical north Atlantic

2014 ◽  
Vol 120 ◽  
pp. 29-40 ◽  
Author(s):  
Joaquim I. Goes ◽  
Helga do Rosario Gomes ◽  
Alexander M. Chekalyuk ◽  
Edward J. Carpenter ◽  
Joseph P. Montoya ◽  
...  
Keyword(s):  
North Atlantic ◽  
River Discharge ◽  
Amazon River ◽  
Tropical North Atlantic ◽  
Phytoplankton Communities

scholarly journals Mesozooplankton Graze on Cyanobacteria in the Amazon River Plume and Western Tropical North Atlantic

2017 ◽  
Vol 8 ◽  
Author(s):  
Brandon J. Conroy ◽  
Deborah K. Steinberg ◽  
Bongkuen Song ◽  
Andrew Kalmbach ◽  
Edward J. Carpenter ◽  
...  
Keyword(s):  
North Atlantic ◽  
River Plume ◽  
Amazon River ◽  
Tropical North Atlantic ◽  
Amazon River Plume

Amazon River influence on nitrogen fixation in the western tropical North Atlantic

2019 ◽  
Vol 77 (2) ◽  
pp. 191-213
Author(s):  
Joseph P. Montoya ◽  
Jason P. Landrum ◽  
Sarah C. Weber
Keyword(s):  
North Atlantic ◽  
Suspended Particle ◽  
Dominant Role ◽  
Amazon River ◽  
N Fixation ◽  
Particulate Nitrogen ◽  
Biological N Fixation ◽  
Relative Contribution ◽  
Tropical North Atlantic

We measured rates of N- and C-fixation with a direct tracer method in regions of the western tropical North Atlantic influenced by the Amazon River plume during the high flow period of 2010 (May–June 2010). We found distinct regional variations in N-fixation activity, with the lowest rates in the plume proper and the highest rates in the plume margins and in offshore waters. A comparison of our N- and C-fixation measurements showed that the relative contribution of N-fixation to total primary production increased from the plume core toward oceanic waters, and that most of the C-fixation in this system was supported by sources of nitrogen other than those derived from biological N-fixation, or diazotrophy. We complemented these rate experiments with measurements of the δ15N of suspended particles (δ15PN), which documented the important and often dominant role of diazotrophs in supplying nitrogen to particulate organic matter in the water column. These coupled measurements revealed that small phytoplankton contributed more new nitrogen to the particulate nitrogen pool than larger phytoplankton. We used a habitat classification method to assess the fac- tors that control diazotrophic activity and contribution to the suspended particle pool, both of which increased from the plume toward oceanic waters. Our findings provide an important constraint on the role of the Amazon plume in creating distinct niches and roles for diazotrophs in the nutrient and carbon budgets of the western tropical North Atlantic.

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