Seasonal and spatial variability in plankton production and respiration in the Subtropical Gyres of the Atlantic Ocean

Gist, N, Serret, P, Woodward, EM, Chamberlain, K and Robinson, C (2009) Seasonal and spatial variability in plankton production and respiration in the Subtropical Gyres of the Atlantic Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography (56). pp. 931-940. ISSN 1879-0100

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    Abstract

    Euphotic zone plankton production (P) and respiration (R) were determined from the in vitro flux of dissolved oxygen during six latitudinal transects of the Atlantic Ocean, as part of the Atlantic Meridional Transect (AMT) programme. The transects traversed the North and South Atlantic Subtropical Gyres (N gyre, 18–38°N; S gyre, 11–35°S) in April–June and September–November 2003–2005. The route and timing of the cruises enabled the assessment of the seasonal variability of P, R and P/R in the N and S gyres, and the comparison of the previously unsampled N gyre centre with the more frequently sampled eastern edge of the gyre. Mean euphotic zone integrated rates (±SE) were P=63±23 (n=31), R=69±22 (n=30) mmol O2 m-2 d-1 in the N gyre; and P=58±26 (n=30), R=62±24 (n=30) mmol O2 m-2 d-1 in the S gyre. Overall, the N gyre was heterotrophic (R>P) and it was more heterotrophic than the S gyre, but the metabolic balance of both gyres changed with season. Both gyres were net heterotrophic in autumn, and balanced in spring. This seasonal contrast was most pronounced for the S gyre, because it was more autotrophic than the N gyre during spring. This may have arisen from differences in nitrate availability, because spring sampling in the S gyre coincided with periods of deep mixing to the nitracline, more frequently than spring sampling within the N gyre. Our results indicate that the N gyre is less heterotrophic than previous estimates suggested, and that there is an apparent decrease in R from the eastern edge to the centre of the N gyre, possibly indicative of an allochthonous organic carbon source to the east of the gyre.

    Item Type: Article
    Faculty \ School: Faculty of Science > School of Environmental Sciences
    University of East Anglia > Faculty of Science > Research Centres > Centre for Ecology, Evolution and Conservation
    University of East Anglia > Faculty of Science > Research Groups > Environmental Biology
    University of East Anglia > Faculty of Science > Research Groups > Resources, Sustainability and Governance
    University of East Anglia > Faculty of Science > Research Groups > Marine and Atmospheric Sciences
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    Depositing User: Rachel Snow
    Date Deposited: 23 Feb 2011 12:59
    Last Modified: 07 Sep 2018 15:30
    URI: https://ueaeprints.uea.ac.uk/id/eprint/24584
    DOI: 10.1016/j.dsr2.2008.10.035

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