A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux
The Amazon generates the world's largest offshore river plume, which covers extensive areas of the tropical Atlantic. The data and samples in this study were obtained during the oceanographic cruise Camadas Finas III in October 2012 along the Amazon River-Ocean Continuum (AROC). The cruise occu...
Main Authors: | , , , , , , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Frontiers Media S.A.
2017-07-01
|
Series: | Frontiers in Microbiology |
Subjects: | |
Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2017.01358/full |
id |
doaj-1f6336b4abe44b2cbb5a11ba9c2ade14 |
---|---|
record_format |
Article |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Moacyr Araujo Moacyr Araujo Carlos Noriega Carlos Noriega Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Doris Veleda Doris Veleda Julia Araujo Leonardo Bruto Leonardo Bruto Fernando Feitosa Manuel Flores-Montes Nathalie Lefèvre Pedro Melo Amanda Otsuka Keyla Travassos Ralf Schwamborn Sigrid Neumann-Leitão |
spellingShingle |
Moacyr Araujo Moacyr Araujo Carlos Noriega Carlos Noriega Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Doris Veleda Doris Veleda Julia Araujo Leonardo Bruto Leonardo Bruto Fernando Feitosa Manuel Flores-Montes Nathalie Lefèvre Pedro Melo Amanda Otsuka Keyla Travassos Ralf Schwamborn Sigrid Neumann-Leitão A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux Frontiers in Microbiology Amazon River-Ocean Continuum biogeochemistry carbon cycle plankton communities Camadas Finas III tropical Atlantic |
author_facet |
Moacyr Araujo Moacyr Araujo Carlos Noriega Carlos Noriega Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Gbekpo Aubains Hounsou-gbo Doris Veleda Doris Veleda Julia Araujo Leonardo Bruto Leonardo Bruto Fernando Feitosa Manuel Flores-Montes Nathalie Lefèvre Pedro Melo Amanda Otsuka Keyla Travassos Ralf Schwamborn Sigrid Neumann-Leitão |
author_sort |
Moacyr Araujo |
title |
A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux |
title_short |
A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux |
title_full |
A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux |
title_fullStr |
A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux |
title_full_unstemmed |
A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux |
title_sort |
synoptic assessment of the amazon river-ocean continuum during boreal autumn: from physics to plankton communities and carbon flux |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Microbiology |
issn |
1664-302X |
publishDate |
2017-07-01 |
description |
The Amazon generates the world's largest offshore river plume, which covers extensive areas of the tropical Atlantic. The data and samples in this study were obtained during the oceanographic cruise Camadas Finas III in October 2012 along the Amazon River-Ocean Continuum (AROC). The cruise occurred during boreal autumn, when the river plume reaches its maximum eastward extent. In this study, we examine the links between physics, biogeochemistry and plankton community structure along the AROC. Hydrographic results showed very different conditions, ranging from shallow well-mixed coastal waters to offshore areas, where low salinity Amazonian waters mix with open ocean waters. Nutrients, mainly NO3− and SiO2−, were highly depleted in coastal regions, and the magnitude of primary production was greater than that of respiration (negative apparent oxygen utilization). In terms of phytoplankton groups, diatoms dominated the region from the river mouth to the edge of the area affected by the North Brazil Current (NBC) retroflection (with chlorophyll a concentrations ranging from 0.02 to 0.94 mg m−3). The North Equatorial Counter Current (NECC) region, east of retroflection, is fully oligotrophic and the most representative groups are Cyanobacteria and dinoflagellates. Additionally, in this region, blooms of cyanophyte species were associated with diatoms and Mesozooplankton (copepods). A total of 178 zooplankton taxa were observed in this area, with Copepoda being the most diverse and abundant group. Two different zooplankton communities were identified: a low-diversity, high-abundance coastal community and a high-diversity, low-abundance oceanic community offshore. The CO2 fugacity (fCO2sw), calculated from total alkalinity (1,450 < TA < 2,394 μmol kg−1) and dissolved inorganic carbon (1,303 < DIC < 2,062 μmol kg−1) measurements, confirms that the Amazon River plume is a sink of atmospheric CO2 in areas with salinities <35 psu, whereas, in regions with salinities >35 and higher-intensity winds, the CO2 flux is reversed. Lower fCO2sw values were observed in the NECC area. The ΔfCO2 in this region was less than 5 μatm (−0.3 mmol m−2 d−1), while the ΔfCO2 in the coastal region was approximately 50 μatm (+3.7 mmol m−2 d−1). During the cruise, heterotrophic and autotrophic processes were observed and are indicative of the influences of terrestrial material and biological activity, respectively. |
topic |
Amazon River-Ocean Continuum biogeochemistry carbon cycle plankton communities Camadas Finas III tropical Atlantic |
url |
http://journal.frontiersin.org/article/10.3389/fmicb.2017.01358/full |
work_keys_str_mv |
AT moacyraraujo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT moacyraraujo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT carlosnoriega asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT carlosnoriega asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT dorisveleda asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT dorisveleda asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT juliaaraujo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT leonardobruto asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT leonardobruto asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT fernandofeitosa asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT manuelfloresmontes asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT nathalielefevre asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT pedromelo asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT amandaotsuka asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT keylatravassos asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT ralfschwamborn asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT sigridneumannleitao asynopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT moacyraraujo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT moacyraraujo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT carlosnoriega synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT carlosnoriega synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT gbekpoaubainshounsougbo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT dorisveleda synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT dorisveleda synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT juliaaraujo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT leonardobruto synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT leonardobruto synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT fernandofeitosa synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT manuelfloresmontes synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT nathalielefevre synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT pedromelo synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT amandaotsuka synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT keylatravassos synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT ralfschwamborn synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux AT sigridneumannleitao synopticassessmentoftheamazonriveroceancontinuumduringborealautumnfromphysicstoplanktoncommunitiesandcarbonflux |
_version_ |
1725931606772809728 |
spelling |
doaj-1f6336b4abe44b2cbb5a11ba9c2ade142020-11-24T21:39:17ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2017-07-01810.3389/fmicb.2017.01358257293A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon FluxMoacyr Araujo0Moacyr Araujo1Carlos Noriega2Carlos Noriega3Gbekpo Aubains Hounsou-gbo4Gbekpo Aubains Hounsou-gbo5Gbekpo Aubains Hounsou-gbo6Doris Veleda7Doris Veleda8Julia Araujo9Leonardo Bruto10Leonardo Bruto11Fernando Feitosa12Manuel Flores-Montes13Nathalie Lefèvre14Pedro Melo15Amanda Otsuka16Keyla Travassos17Ralf Schwamborn18Sigrid Neumann-Leitão19Department of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilBrazilian Research Network on Global Climate Change (Rede CLIMA)São José dos Campos, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilBrazilian Research Network on Global Climate Change (Rede CLIMA)São José dos Campos, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilBrazilian Research Network on Global Climate Change (Rede CLIMA)São José dos Campos, BrazilInternational Chair in Mathematical Physics and Applications (UNESCO Chair), Université d'Abomey-CalaviCotonou, BeninDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilBrazilian Research Network on Global Climate Change (Rede CLIMA)São José dos Campos, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilBrazilian Research Network on Global Climate Change (Rede CLIMA)São José dos Campos, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilIIRD-LOCEAN (Laboratoire d'Océanographie et du Climat: Expérimentations et Approches Numériques), Sorbonne Universités (Université Pierre et Marie Curie, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle)Paris, FranceDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilDepartment of Oceanography (DOCEAN), Federal University of Pernambuco (UFPE)Recife, BrazilThe Amazon generates the world's largest offshore river plume, which covers extensive areas of the tropical Atlantic. The data and samples in this study were obtained during the oceanographic cruise Camadas Finas III in October 2012 along the Amazon River-Ocean Continuum (AROC). The cruise occurred during boreal autumn, when the river plume reaches its maximum eastward extent. In this study, we examine the links between physics, biogeochemistry and plankton community structure along the AROC. Hydrographic results showed very different conditions, ranging from shallow well-mixed coastal waters to offshore areas, where low salinity Amazonian waters mix with open ocean waters. Nutrients, mainly NO3− and SiO2−, were highly depleted in coastal regions, and the magnitude of primary production was greater than that of respiration (negative apparent oxygen utilization). In terms of phytoplankton groups, diatoms dominated the region from the river mouth to the edge of the area affected by the North Brazil Current (NBC) retroflection (with chlorophyll a concentrations ranging from 0.02 to 0.94 mg m−3). The North Equatorial Counter Current (NECC) region, east of retroflection, is fully oligotrophic and the most representative groups are Cyanobacteria and dinoflagellates. Additionally, in this region, blooms of cyanophyte species were associated with diatoms and Mesozooplankton (copepods). A total of 178 zooplankton taxa were observed in this area, with Copepoda being the most diverse and abundant group. Two different zooplankton communities were identified: a low-diversity, high-abundance coastal community and a high-diversity, low-abundance oceanic community offshore. The CO2 fugacity (fCO2sw), calculated from total alkalinity (1,450 < TA < 2,394 μmol kg−1) and dissolved inorganic carbon (1,303 < DIC < 2,062 μmol kg−1) measurements, confirms that the Amazon River plume is a sink of atmospheric CO2 in areas with salinities <35 psu, whereas, in regions with salinities >35 and higher-intensity winds, the CO2 flux is reversed. Lower fCO2sw values were observed in the NECC area. The ΔfCO2 in this region was less than 5 μatm (−0.3 mmol m−2 d−1), while the ΔfCO2 in the coastal region was approximately 50 μatm (+3.7 mmol m−2 d−1). During the cruise, heterotrophic and autotrophic processes were observed and are indicative of the influences of terrestrial material and biological activity, respectively.http://journal.frontiersin.org/article/10.3389/fmicb.2017.01358/fullAmazon River-Ocean Continuumbiogeochemistrycarbon cycleplankton communitiesCamadas Finas IIItropical Atlantic |