Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia

Differential mercury transfer in the aquatic food web of a double basined lake associated with selenium and habitat

“…1). Each basin has a different morphometry with the steeper basin having strong pelagic component in contrast to the other gently sloping basin having a greater littoral component (Queimaliños et al, 2012), which conforms to the typical morphometric influences on pelagic-littoral coupling in literature (Dolson et al, 2009). Pelagic-littoral coupling in both basins of Lake Moreno is mediated mainly through ontogenetic development of key fish species, with larval and juvenile fish feeding upon plankton and shifting to benthic prey and fish as they grow (Macchi et al, 2007;Vigliano et al, 2009).…”

“…1). It has two connected basins, Moreno East (ME) and Moreno West (MW), considered as independent lakes, with waters flowing from ME to MW (Queimaliños et al, 2012). Paleolimnological studies indicate Hg sources in Lake Moreno are likely from natural origins, with dated sediment [Hg] peaks corresponding with known dates of extended forest fires and volcanic activity (Ribeiro Guevara et al, 2010).…”

Stable isotope analysis of trophic structure, energy flow and spatial variability in a large ultraoligotrophic lake in Northwest Patagonia

“…Yuma et al, 2006). In this sense, Queimaliños et al (2012) found that the neighboring connected lakes (Moreno West and Moreno East) have the same surface area but differential allochthonous indicators in the pelagic zone. This is related to the differences of perimeter-lake area ratio of both lakes, and the consequent dissimilarities of contact between the lake and the terrestrial environment.…”

“…2). The differences in δ 13 C of copepods and cladocerans may be explained by the selective feeding behavior of copepods for autochthonous resources depleted in 13 C (Pulido-Vilena et al, 2005) compared with cladocerans which directly graze on bacteria that rely on allochthonous organic matter which is usually enriched in 13 C (del Giorgio and France, 1996;Taipale et al, 2008;Queimaliños et al, 2012).…”

“…In contrast, δ 13 C values of consumers change little with trophic transfers (Post, 2002) consequently they can be used to determine original sources of dietary carbon (Layman et al, 2011). This approach has been used in North Patagonian lakes to analyze and compare the food web structure of the double-basin system of Lake Moreno (Arcagni et al, 2013), which is characterized by contrasting hydrogeomorphic characteristics in each basin (Queimaliños et al, 2012). Lake Moreno is an ultraoligotrophic lake that flows through a short river into Lake Nahuel Huapi and possesses a similar food web structure as the larger lake.…”