MODENUTTI Beatriz Estela
Effect of glacial lake outburst floods on the light climate in an Andean Patagonian lake: implications for planktonic phototrophs.
BASTIDAS NAVARRO, M.,; MARTYNIUK, N; E. BALSEIRO,; B. MODENUTTI,
Lugar: Berlin; Año: 2017
Climatechange is altering temperature and precipitation patterns all over the world.In North Patagonia, glaciers of the Tronador mountain (41° S) show a continuousand maintained recession and these meltwaters are transported to Lake Mascardivia the Upper Manso River that carries a large amount of glacial clay. Thesesuspended sediment particles cause a very sharp light longitudinal gradientalong the western branch of Lake Mascardi (Tronador arm). Here we analysedchanges in the water transparency along the gradient, in particular before andafter a glacial lake outburst flood (GLOF) event that occurred in theheadwaters that feed Lake Mascardi. The GLOF caused a significant decrease inturbidity over the years following the event. The depth of the deep chlorophyllmaxima (DCM) was directly related to the light penetration, and the decrease insuspended solids load deepened the DCM in the years after the GLOF event. Amongphotosynthetic organisms, picocyanobacteria were observed to have a significantincrease in abundance to these light changes and total nanoflagellateabundances increased after the GLOF event when transparency increased due tothe decrease in the clay and sediment inputs into the lake. Our datademonstrated that the DCM and phytoplankton are useful variables to predictchanges in the lake light climate.