TEMPORETTI pedro Felix
Lake Caviahue: an extreme environment as a potential sentinel for nutrient deposition in Patagonia
BAFFICO, G; DIAZ, M; BEAMUD, G; SCHULTZ, S.; TEMPORETTI, P.; PEDROZO, F.
The objective of this study was to determineif extreme acidic Lake Caviahue could be used asa sentinel of atmospheric deposition hypothesizingthat the physiological state of algae will be theindicator parameter. The lake was sampled from 2000to 2015 in order to determine chlorophyll concentration,algae abundance and phytoplankton in vivofluorescence as a way to evaluate the physiologicalstate of algae. Development and physiological state ofphytoplankton in different seasons was related toconcentration and dynamics of nutrients in the lake.Laboratory experiments of Keratococcus rhaphidiodesto nitrogen (N) enrichment confirmed that anincrease in nutrient content enabled a better physiologicalstate of algae (e.g. higher chlorophyll per cell).Therefore, under the projected scenarios of climatechange, the increase of available N through theincrease in deposition and the increase of dissolvedinorganic carbon, as consequence of higher atmosphericCO2, will compensate the natural nutrientconstraints observed in the phytoplankton of the lake.The effect that the atmospheric CO2 has on the DIC,and this on algal development, as well as the influencethat N has on algal growth, make Lake Caviahue aninteresting sentinel of nutrient deposition at regionallevel.