PUBLICACIONES

Poster. 3rd Blue Planet Symposium. Maryland, USA, 31 May to 2 June 2017.

Atmospheric accumulation of CO₂ due to anthropogenic actions has increased the need to better understand the global carbon cycle. It is estimated that uptake by the global ocean has reduced the increase in CO₂ emissions by around 26%. Nevertheless, this uptake is not homogeneous; it may vary as a result of environmental conditions and to biological changes, specially the types and physiological response of phytoplankton. Phytoplanktonic photosynthesis provides in this way an ecosystem service of regulation, which for the most part remains “invisible” to society since it is not measured (quite in contrast to the case of carbon sequestration by forests, a regulation service that is regularly measured).

            In this case study we make use of information from Argentina obtained from different platforms/sources: a) in situ data (chlorophyll-a concentration, proportion of three size-classes of phytoplankton) from the coastal time series EPEA; b) satellite data from MODIS-Aqua (chlorophyll-a concentration); c) modeled data from NEMO (chlorophyll-a concentration, primary production, differential partial pressure of CO₂ between the ocean and the atmosphere or DpCO₂); d) national inventories of GHG emissions. Our preliminary results have shown a trend towards an increase in chlorophyll-a concentration at EPEA (both from in situ and satellite estimations) during the period 2000-2015. Furthermore, this increase was more pronounced for the <5 mm fraction, which is coincident with an increase in the proportion of the pico-phytoplankton community, and a modest increase in DpCO₂ as estimated by NEMO. Analyses at a narrow spatial scale (around the EPEA station), are consistent with the trends retrieved by the different estimations. Finally integrated values of DpCO₂ (from NEMO) will be compared with the values of GHG emissions provided by recent inventories (from the last two National Communications). This will provide a first “indicator” of the relevance of the regulation ecosystem service provided by the ocean that may help make it more visible as well as help analyze the socioeconomic implications of conservation efforts.

This work represents an attempt towards using detailed in situ and satellite observations to explain trends in other relevant variables provided by a model, and to translate these results into policy-relevant information.  This study will be completed with further information from additional Latin-American countries from the ANTARES network in the near future, and it is a contribution of the IAI-CRN3094 project.