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

TEMPORETTI P; BEAMUD SG; LEÓN JOSÉ; ROTONDO L

Environmental Assessment of Patagonia's Water Resources

Springer International Publishing Copyright Holder

Año: 2021;

Among the processes of anthropogenic contamination ofaquatic environments, eutrophication is one of the most studied. Phosphorus isa key nutrient in eutrophication and, in many cases, the limiting nutrient invarious water bodies. Furthermore, sediments from an aquatic environment can beconsidered as an ?environmental information bank?. They play an important rolein the nutrient 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 ArgentinianPatagoniaand their role in aquatic resource assessment. A totalof 11 waterbodies in the region were analyzed, considering different physicaland chemical parameters, always applying the same methodology (in field andlaboratory). The results show that 1) pH is one of the main parameters thatinfluence the P exchange between sediments and the water column; 2) texture,chemical composition, and mineralogy are essential to understand sedimentgenesis and transport mechanisms; 3) three gradients determine the distributionof the studied environments: a) North-South geographic gradient, b) pH gradientand c) trophic gradient; 4) the use of sediment bioassays with native algae isa particularly useful tool for rapidly evaluating the anthropic impact on waterbodies; and 5) sediment studies allow obtaining information on, for example,contaminated and uncontaminated areas and distribution patterns ofcontaminants, and should be included in monitoring programs.