First Observations on Zooplankton and Optical Properties in a Glacial North Patagonian Lake (Tagua Tagua Lake, 41°S Chile)

Abstract

The Patagonian lakes are of glacial origin and some of these are associated with glaciers that generate specific optical properties such as water colorations due to glacier sediments. These lakes also are oligotrophic with a low crustacean zooplankton species number. The aim of the present study was to analyze potential associations between optical properties and zooplankton communities in Tagua Tagua Lake (41°S). The results revealed inverse associations in reflectance of bands 3 and 7 of LANDSAT TM+ with Daphnia ambigua, Mesocyclops araucanus, and nauplius, and direct Neobosmina chilensis and Cyclopoids copepodites, whereas it was inverse relations between bands 5 and 2 with B. gracilipes and calanoid copepodites that make this zooplankton assemblage similar to Nord Patagonian oligomesotrophic lakes. These results would agree with few reports for other similar Patagonian lakes of glacial origin reported for Argentinean and Chilean Patagonia. Nevertheless, it is necessary for more studies to find potential associations between limnological characters and optical properties.

First Observations of Boeckella michaelseni Mrázek 1901 in and Optical Properties of a Central Patagonian Lake

“…This situation differs from another Patagonian lake with glacial influence, Todos los Santos Lake, which has four species [1]. The relation between optical properties and zooplankton community composition has been reported for similar Patagonian lakes such as Tagua Tagua [4] and General Carrera [6].…”

“…In this scenario the optical properties of water bodies would be related to zooplankton communities such as those observed preliminarily for lakes General Carrera [6] and Tagua Tagua [4]. General Carrera is a binational lake that is shared with Argentina, where it is called as Buenos Aires lake [6].…”

“…Zooplankton samples were taken using vertical hauls of 15 m with plankton net of 20 cm diameter and 100 µm mesh size. Zooplankton specimens were fixed in absolute ethanol and they were identified by microscoping analysis based on specialized literature [7,8] and quantified in a laboratory using all specimens in samples [4,6]. The site was visited on 2 February 2013.…”

“…The Patagonian lakes located in southern Argentina and Chile (38-51°S) are of glacial origin [1][2][3][4], and some of these lakes are associated with ice fields in their surrounding basins that generate specific characteristics in landscapes such as those observed in Grey Lake in Torres del Paine National Park [5], or water colorations specifics for each lake, for example greenish bays in General Carrera or Todos los Santos lakes [1,6]. Also, the Patagonian lakes are characterized by their marked oligotrophy (2.1-0.4 µg/L Chlorophyll a) [1,5] generated as a consequence of low crustacean zooplankton species richness and the predominance of calanoids copepods of Boeckella and Tumeodiaptomus genera [1].…”

Spectral Properties Observations in Lakes of a Chilean National Park

“…denoted using remote sensing techniques determined for Patagonian lakes with marked environmental heterogeneity such as were observed for Tagua Tagua and General Carrera lakes [4][5][6]. The environmental heterogeneity for Patagonian lakes has been described with details mainly in trophic status and associated basins [7][8][9], but recently optical properties associated with ecological implicances due to the presence of associated glaciers with consequent changes in water coloration properties, light absorption, and changes in associated trophic webs have been studied [10][11][12], and these results can be associated with optical properties obtained from satellite images [4][5][6]. Many of these lakes are located in zones with serious accessibility issues, and only a few of them are not accessible by mountain paths [1,3].…”