The environmental state of Argentinean lakes: An overview

Abstract

Due to the great climatic variety and the peculiar north–south orographic distribution, Argentinean lake systems include a wide diversity of aquatic environments. The deepest lakes are situated in the Andean Patagonia and Tierra del Fuego, and range from ultraoligotrophic to oligotrophic. Patagonian Plateau lakes are shallower than Andean lakes and usually range from mesotrophic to eutrophic. All lakes in the Chaco‐Pampa Plain are very shallow and range from eutrophic to hypertrophic or salt lakes. Most of the lakes situated in the central–western and northwestern arid regions are reservoirs or salt lakes, and range from mesotrophic to eutrophic. More than half of the northwestern reservoirs have very low dissolved oxygen concentrations in the hypolimnion during mid‐summer. Argentina has more than 400 lakes with surface area >5 km2, but for some of them not even major ion data are available. In order to synthesize and to extract general characteristics and patterns, issues have been selected which adequately reflect the character of the lake environment in Argentina. We divided Argentina according to geographical regions into six major divisions: Puna, Chaco‐Pampa Plain, Peri‐Pampean Sierras, Andean Patagonia, Patagonian Plateau, and Misiones Plateu and Brazilian Shield‐related systems. Most of the lakes situated in Patagonia are undisturbed lakes. However, the Chaco‐Pampa Plain lakes are usually lightly impacted by agricultural operations. Moreover, most of the reservoirs located in the Argentinean arid ‘corridor’ are highly impacted by agriculture. Other lakes in both north and south Argentina range from salt lakes, through dark humic‐stained lakes and large river floodplain lakes, to dilute high altitude glacial lakes. Argentina still has a larger proportion of its lake waters in natural conditions. However, expected developments for natural resources indicates that Argentinean goals for lake water management should include the preservation of some proportion of pre‐European natural lake environment, and the evolution of a stable, managed lake environment in the more developed regions.

Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile)

“…The literature indicates that chlorophyll and conductivity would be the main regulator factors in crustacean assemblages in Chilean lakes and ponds (De los Ríos-Escalante, 2010), and similar results are found in Argentinean lakes (Quiros and Drago, 1999). Although the present results did not include chlorophyll concentration, the presence of daphnid cladocerans, such as D. ambigua and C. dubia, and cyclopoid copepods would indicate the presence of relatively moderate chlorophyll concentrations (Jeppesen et al, 1997(Jeppesen et al, , 2000De los Ríos and Soto, 2009;De los Ríos-Escalante, 2010).…”

Diversity of the fatty acid composition of Artemia spp. cysts from Argentinean populations

“…Quirós & Drago (1999) studied Argentina according to geomorphological traits and established 6 major regions: (1) Puna, (2) Chaco-Pampa Plain, (3) PeriPampean Sierras, (4) Andean-Patagonia, (5) Patagonia Plateau and (6) Misiones Plateau. They determined that the principal mechanisms influencing the chemistry of inland waters were rock dominance and evaporation, with atmospheric contributions being less important.…”

“…Populations from El Inglés, Piedras, Algarrobo, Gualicho, Caleta Olivia, Ruta 3 and San Julián are located on the Patagonia Plateau region, whose large hypersaline 'salares' host medium-high salinity (10 to 100 g l -1 ) waters. We compared the percentages of major ions from brines analysed in this study with those reported by Quirós & Drago (1999) for Argentinean lakes; 7 lagoons are located within the Chaco-Pampa Plain (Table 3), whereas the remaining 5 lagoons are located on the Patagonia Plateau and are largely characterized by water chemistry typical of endorheic basins.…”

“…Perhaps the most updated information on this topic is available from Quirós & Drago (1999); however, this review only gives the common characteristics of a few representative lakes from each region, and it is therefore very difficult to characterize each lake individually. Within the biotopes associated with the Artemia populations studied here, the anionic fraction of brines was dominated by Cl -and the cationic fraction by Na + .…”

Mapping and Monitoring Lakes Intra-Annual Variability in Semi-Arid Regions: A Case of Study in Patagonian Plains (Argentina)

“…The lakes in this area, which are the largest and deepest in South America [29], play a crucial role for the local and regional population, and the developing opportunities of the area [30,31]. The impact of climate variability on water resources is especially critical for this region [32][33][34].…”