Perspective: continental inputs of matter into planktonic ecosystems of Argentinean continental shelf - the case of atmospheric dust

AUGUSTO CÉSAR CRESPI-ABRIL; ELENA BARBIERI; LEILEN VILLALOBOS-GRACIA; GASPAR SORIA; FLAVIO PAPARAZZO; JOANNA PACZKOWSKA; RODRIGO GONCALVES

Plankton Ecology of the Southwestern Atlantic, from Subtropical to the Subantarctic realm

Springer

Año: 2018; p. 1 - 100

Land-deriveddissolved and particulate matter (allochthonous matter) affect pelagicecosystems by changing factors which include light penetration, nutrientavailability, substrate concentration and, in general, biogeochemical cycles inthe ocean. In a context of increasing anthropogenic impact, this material maynot only increase its load but also carry toxic substances. Riverine runoff isthe most studied mechanism of particulate matter input from the continent tothe shelf in the southern region of South America where the continental shelfis widest (e.g., Atlantic Patagonia). However, there are other sources ofparticulate matter which are not affected by rivers in this semi-arid region: aeolianmaterial. Winds in this region (notably the South Hemisphere Westerlies) arethe only way continental aeolian material (atmospheric aerosols or ?dust?) canreach not only the shelf but even further onto oceanic HNLC (High Nutrients-Low Chlorophyll) waters of the Atlantic Southern Ocean. This potential impactof Patagonian dust beyond the continental shelf attracts attention to theglobal climate community, and at the same time it opens questions about the potentialeffects of dust in coastal waters. According to previous work and ongoingstudies, deposited particles can have significant impacts in the chemical andbiological components in the euphotic zone. However the effects of thisairborne material in plankton ecosystems of South America is largely unknown,mostly due to lack of in situ studies and observations. Since the events ofdust mobilization, transport and deposition are expected to increase (due toclimate change) and interact with other global change factors such as warmingand more intensive land use, the influence of dust input may become moreprominent for coastal and oceanic regions of southern South America in the nextdecades.