Introduction to the special section Bio-optical and biogeochemical conditions in the South East Pacific in late 2004: the BIOSOPE program

Abstract. The objectives of the BIOSOPE (BIogeochemistry and Optics SOuth Pacific Experiment) project was to study, during the austral summer, the biological, biogeochemical and bio-optical properties of different trophic regimes in the South East Pacific: the eutrophic zone associated with the upwelling regime of the Chilean coast, he mesotrophic area associated with the plume of the Marquises Islands in the HNLC (High Nutrient Low Chlorophyll) waters of this subequatorial area, and the extremely oligotrophic area associated with the central part of the South Pacific Gyre (SPG). At the end of 2004, a 55-day international cruise with 32 scientists on board took place between Tahiti and Chile, crossing the SPG along a North-West South-East transect. This paper describes in detail the objective of the BIOSOPE project, the implementation plan of the cruise, the main hydrological entities encountered along the ~8000 km South East pacific transect and ends with a general overview of the papers published in this Biogeosciences special issue.

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Introduction to the special section bio-optical and biogeochemical conditions in the South East Pacific in late 2004: the BIOSOPE program

Biogeosciences ◽

10.5194/bg-5-679-2008 ◽

2008 ◽

Vol 5 (3) ◽

pp. 679-691 ◽

Cited By ~ 73

Author(s):

H. Claustre ◽

A. Sciandra ◽

D. Vaulot

Keyword(s):

Optical Properties ◽

Special Section ◽

Austral Summer ◽

South Pacific ◽

Special Issue ◽

The South ◽

North West ◽

East Pacific ◽

High Nutrient ◽

South Pacific Gyre

Abstract. The objectives of the BIOSOPE (BIogeochemistry and Optics SOuth Pacific Experiment) project was to study, during the austral summer, the biological, biogeochemical and bio-optical properties of different trophic regimes in the South East Pacific: the eutrophic zone associated with the upwelling regime off the Chilean coast, the mesotrophic area associated with the plume of the Marquises Islands in the HNLC (High Nutrient Low Chlorophyll) waters of this subequatorial area, and the extremely oligotrophic area associated with the central part of the South Pacific Gyre (SPG). At the end of 2004, a 55-day international cruise with 32 scientists on board took place between Tahiti and Chile, crossing the SPG along a North-West South-East transect. This paper describes in detail the objectives of the BIOSOPE project, the implementation plan of the cruise, the main hydrological entities encountered along the ~8000 km South East Pacific transect, and ends with a general overview of the 32 other papers published in this special issue.

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Heterotrophic bacterial production in the South East Pacific: longitudinal trends and coupling with primary production

Biogeosciences Discussions ◽

10.5194/bgd-4-2761-2007 ◽

2007 ◽

Vol 4 (4) ◽

pp. 2761-2791 ◽

Cited By ~ 11

Author(s):

F. Van Wambeke ◽

I. Obernosterer ◽

T. Moutin ◽

S. Duhamel ◽

O. Ulloa ◽

...

Keyword(s):

Pacific Ocean ◽

Primary Production ◽

Bacterial Production ◽

South Pacific ◽

Leucine Incorporation ◽

The South ◽

Phytoplankton Primary Production ◽

East Pacific ◽

Wide Range ◽

South Pacific Gyre

Abstract. Spatial variations of heterotrophic bacterial production and phytoplankton primary production were investigated across South East Pacific Ocean (–141° W, –8° S to –72° W, –35° S) in November–December 2004. Bacterial production (³H leucine incorporation) integrated over the euphotic zone encompassed a wide range of values, from 43 mg C m−2 d−1 in the hyper-oligotrophic South Pacific Gyre to 392 mg C m−2 d−1 in the upwelling off Chile. Within the gyre (120° W, 22° S) records of low phytoplankton biomass (7 mg TChla m−2) were obtained and in situ 14C based particulate primary production rates were as low as 153 mg C m−2 d−1, thus equal to the value considered as a limit for primary production under strong oligotrophic conditions. In the South Pacific gyre average rates of ³H leucine incorporation rates, and leucine incorporation rates per cell (5–21 pmol L−1 h−1 and 15–56×10−21 mol cell−1 h−1, respectively), were in the same range as those reported for other oligotrophic sub tropical and temperate waters. Rates of dark community respiration, determined at selected stations across the transect varied in a narrow range (42–97 mmol O2 m−2 d−1), except for one station in the upwelling off Chile (245 mmol O2 m−2 d−1). Bacterial growth efficiencies varied between 5 and 38% and bacterial carbon demand largely exceeded 14C particulate primary production across the South Pacific Ocean. Net community production also revealed negative values in the South Pacific Gyre (–13±20 to –37±40 mmol O2 m−2 d−1). Such imbalances being impossible in this area far from any external input, we discuss the techniques involved for determining the coupling between primary production and bacterial heterotrophic production.

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A description of late and transformation stages of larvae of the Diaphus ostenfeldi in the western periphery of the South Pacific Gyre

Fishery Bulletin ◽

10.7755/fb.118.4.1 ◽

2020 ◽

Vol 118 (4) ◽

pp. 319-323

Author(s):

Sergei A. Evseenko ◽

Yana Yu. Bolshakova

Keyword(s):

South Pacific ◽

The South ◽

South Pacific Gyre

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Calcite production by Coccolithophores in the South East Pacific Ocean: from desert to jungle

Biogeosciences Discussions ◽

10.5194/bgd-4-3267-2007 ◽

2007 ◽

Vol 4 (5) ◽

pp. 3267-3299 ◽

Cited By ~ 16

Author(s):

L. Beaufort ◽

M. Couapel ◽

N. Buchet ◽

H. Claustre

Keyword(s):

Size Range ◽

Digital Camera ◽

Euphotic Zone ◽

The South ◽

Carbonate Ions ◽

East Pacific ◽

Standing Stocks ◽

South Pacific Gyre ◽

East Pacific Ocean ◽

First Time

Abstract. BIOSOPE cruise achieved an oceanographic transect from the Marquise Islands to the Peru-Chili upwelling (PCU) via the centre of the South Pacific Gyre (SPG). Water samples from 6 depths in the euphotic zone were collected at 20 stations. The concentrations of suspended calcite particles, coccolithophores cells and detached coccoliths were estimated together with size and weight using an automatic polarizing microscope, a digital camera, and a collection of softwares performing morphometry and pattern recognition. Some of these softwares are new and described here for the first time. The coccolithophores standing stocks are usually low and reach maxima west of the PCU. The coccoliths of Emiliania huxleyi, Gephyrocapsa spp. and Crenalithus spp. (Order Isochrysidales) represent 50% of all the suspended calcite particles detected in the size range 0.1–46 μm (21% of PIC in term of the calcite weight). The latter species are found to grow preferentially in the Chlorophyll maximum zone. In the SPG their maximum concentrations was found to occur between 150 and 200 m, which is very deep for these taxa. The weight and size of coccoliths and coccospheres are correlated. Large and heavy coccoliths and coccospheres are found in the regions with relative higher fertility in the Marquises Island and in the PCU. Small and light coccoliths and coccospheres are found west of the PCU. This distribution may correspond to that of the concentration of calcium and carbonate ions.

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Volume distribution for particles between 3.5 to 2000 μm in the upper 200 m region of the South Pacific Gyre

Biogeosciences ◽

10.5194/bg-5-299-2008 ◽

2008 ◽

Vol 5 (2) ◽

pp. 299-310 ◽

Cited By ~ 28

Author(s):

L. Stemmann ◽

D. Eloire ◽

A. Sciandra ◽

G. A. Jackson ◽

L. Guidi ◽

...

Keyword(s):

Weight Ratio ◽

South Pacific ◽

Dry Weight ◽

Volume Distribution ◽

The South ◽

Size Spectra ◽

Marquesas Islands ◽

Large Particles ◽

Living Organisms ◽

South Pacific Gyre

Abstract. The French JGOFS BIOSOPE cruise crossed the South Pacific Gyre (SPG) on a transect between the Marquesas Islands and the Chilean coast on a 7500 km transect (8° S–34° S and 8° W–72° W). The number and volume distributions of small (3.5100 μm) were analysed combining two instruments, the HIAC/Royco Counter (for the small particles) and the Underwater Video Profiler (UVP, for the large particles). For the HIAC analysis, samples were collected from 12 L CTD Rosette bottles and immediately analysed on board while the UVP provided an estimate of in situ particle concentrations and size in a continuous profile. Out of 76 continuous UVP and 117 discrete HIAC vertical profiles, 25 had both sets of measurements, mostly at a site close to the Marquesas Islands (site MAR) and one in the center of the gyre (site GYR). At GYR, the particle number spectra from few μm to few mm were fit with power relationships having slopes close to −4. At MAR, the high abundance of large objects, probably living organisms, created a shift in the full size spectra of particles such that a single slope was not appropriate. The small particle pool at both sites showed a diel pattern while the large did not, implying that the movement of mass toward the large particles does not take place at daily scale in the SPG area. Despite the relatively simple nature of the number spectra, the volume spectra were more variable because what were small deviations from the straight line in a log-log plot were large variations in the volume estimates. In addition, the mass estimates from the size spectra are very sensitive to crucial parameters such as the fractal dimension and the POC/Dry Weight ratio. Using consistent values for these parameters, we show that the volume of large particles can equal the volume of the smaller particles. However the proportion of material in large particles decreased from the mesotrophic conditions at the border of the SPG to the ultra-oligotrophy of the center in the upper 200 m depth. We expect large particles to play a major role in the trophic interaction in the upper waters of the South Pacific Gyre.

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Microbial community composition and nitrogen availability influence DOC remineralization in the South Pacific Gyre

Marine Chemistry ◽

10.1016/j.marchem.2015.06.024 ◽

2015 ◽

Vol 177 ◽

pp. 325-334 ◽

Cited By ~ 21

Author(s):

Robert T. Letscher ◽

Angela N. Knapp ◽

Anna K. James ◽

Craig A. Carlson ◽

Alyson E. Santoro ◽

...

Keyword(s):

Microbial Community ◽

Community Composition ◽

Nitrogen Availability ◽

Microbial Community Composition ◽

South Pacific ◽

The South ◽

South Pacific Gyre

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Special Issue: New Zealand and the South Pacific

Journal of New Zealand & Pacific Studies ◽

10.1386/nzps.2.2.117_2 ◽

2014 ◽

Vol 2 (2) ◽

pp. 117-119

Author(s):

Ian Conrich ◽

Toon Van Meijl

Keyword(s):

New Zealand ◽

South Pacific ◽

Special Issue ◽

The South

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Ocean Warming Effect on Surface Gravity Wave Climate Change for the End of the Twenty-First Century

Journal of Climate ◽

10.1175/jcli-d-12-00410.1 ◽

2013 ◽

Vol 26 (16) ◽

pp. 6046-6066 ◽

Cited By ~ 43

Author(s):

Yalin Fan ◽

Isaac M. Held ◽

Shian-Jiann Lin ◽

Xiaolan L. Wang

Keyword(s):

Climate Change ◽

North Atlantic ◽

Austral Summer ◽

South Pacific ◽

First Century ◽

The South ◽

Coupled Models ◽

The North ◽

The North Atlantic ◽

Twenty First Century

Abstract Surface wind (U10) and significant wave height (Hs) response to global warming are investigated using a coupled atmosphere–wave model by perturbing the sea surface temperatures (SSTs) with anomalies generated by the Working Group on Coupled Modeling (WGCM) phase 3 of the Coupled Model Intercomparison Project (CMIP3) coupled models that use the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4)/Special Report on Emissions Scenarios A1B (SRES A1B) scenario late in the twenty-first century. Several consistent changes were observed across all four realizations for the seasonal means: robust increase of U10 and Hs in the Southern Ocean for both the austral summer and winter due to the poleward shift of the jet stream; a dipole pattern of the U10 and Hs with increases in the northeast sector and decreases at the midlatitude during boreal winter in the North Atlantic due to the more frequent occurrence of the positive phases of the North Atlantic Oscillation (NAO); and strong decrease of U10 and Hs in the tropical western Pacific Ocean during austral summer, which might be caused by the joint effect of the weakening of the Walker circulation and the large hurricane frequency decrease in the South Pacific. Changes of the 99th percentile U10 and Hs are twice as strong as changes in the seasonal means, and the maximum changes are mainly dominated by the changes in hurricanes. Robust strong decreases of U10 and Hs in the South Pacific are obtained because of the large hurricane frequency decrease, while the results in the Northern Hemisphere basins differ among the models. An additional sensitivity experiment suggests that the qualitative response of U10 and Hs is not affected by using SST anomalies only and maintaining the radiative forcing unchanged (using 1980 values), as in this study.

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