The Role of Sediments and Phosphorus in the Evaluation of Water Resources Quality in Patagonia.

TEMPORETTI PEDRO; BEAMUD GUADALUPE; LEÓN JOSÉ; ROTONDO LEANDRO; CUEVAS MAYRA; PEDROZO FERNANDO

Environmental Assessment of Patagonia?s Water Resources

Springer Nature Switzerland AG

Año: 2021; p. 211 - 240

Among theprocesses of anthropogenic contamination of aquatic environments,eutrophication is one of the most studied. Phosphorus is a key nutrient ineutrophication and, in many cases, the limiting nutrient in various waterbodies. Furthermore, sediments from an aquatic environment can be considered asan ?environmental information bank?. They play an important role in thenutrient cycle in lakes since nutrients are transported to the bottom bysedimentation and can return to the water column by various mechanisms whichare sometimes extremely complex. The aim of this chapter is to summarize 30years of research carried out by the Water Quality Group (INIBIOMA,CONICET-UNComahue) on sediments from several lake environments in ArgentinianPatagonia and their role in aquatic resource assessment. A total of 11 waterbodies in the region were analyzed, considering different physical and chemicalparameters, always applying the same methodology (in field and laboratory). Theresults show that (1) pH is one of the main parameters that influence the Pexchange between sediments and the water column; (2) texture, chemicalcomposition, and mineralogy are essential to understand sediment genesis and transportmechanisms; (3) three gradients determine the distribution of the studied environments:(a) North?South geographic gradient, (b) pH gradient and (c) trophic gradient;(4) the use of sediment bioassays with native algae is a particularly useful toolfor rapidly evaluating the anthropic impact on water bodies; and (5) sediment studiesallow obtaining information on, for example, contaminated and uncontaminatedareas and distribution patterns of contaminants, and should be included in monitoringprograms.