Overview on primary production in the Southwestern Atlantic

Abstract

Photosynthesis is the fundamental process by which autotrophs produce organic matter to sustain the biosphere using basic elements (i.e., CO2 and H2O) and solar irradiance as energy source. Marine phytoplankton provides near half of the global primary production (PP), being at the base of most marine trophic webs and playing an important role in the cycling of atmospheric CO2. Therefore, it is crucial to estimate and understand the relationships between environmental conditions and PP rates in the global ocean. There are scarce field estimations of PP in the southern hemisphere and in the Southwestern Atlantic in particular. Hence, global estimates are generally made using indirect methods, such as satellite or biogeochemical models, which should be validated and adjusted with field data to produce reliable results. In this section we synthesize the available information, assembling recent field PP estimations obtained by research groups from Argentina, Brazil, and Uruguay. We evaluate the insights derived from this integrated dataset on the spatial and temporal dynamics of the phytoplankton production in the Southwestern Atlantic. In addition, a general view of the spatial-temporal variation in PP at a regional scale using a simple satellite PP model is presented. Finally, we offer perspectives and recommendations for future studies.