Laboratorio de Limnologia

Laboratory of Limnology - CONICET-UNC

Bariloche - Patagonia - Argentina

Laboratory of Limnology

Located within the North Patagonian Andean Lake District in Argentina, a region of abundant and diverse aquatic ecosystems, the Laboratorio de Limnología of the Universidad Nacional del Comahue develop basic and applied research in limnology.

The laboratory was created in 1987, and since then, the staff has carried out research programs funded by national and international scientific agencies. The scientific work is mainly focused on the analysis of the trophic interactions and food web dynamics of lakes and rivers of the Andean Patagonian region including the impacts of human activities.

The large and deep lakes are ultraoligotrophic and warm monomictic. Lake water is extremely transparent with euphotic zones up to 55 m depth in the case of Nahuel Huapi lake. These conditions bring out a deep distribution of planktonic organisms, constituting a deep chlorophyll maxima, which is characteristic of these large ultraoligotrophic lakes with low dissolved organic carbon concentrations. Recent investigations of in-lake processes include analysis of fundamental patterns of vertical profiles in light and chlorophyll a concentrations in relation with the particular dynamics of microbial food webs, which are dominated by large mixotrophic ciliates and dinoflagellates. Currently we are working on the effect of global change on light quality, primary production and planktonic biodiversity.

We are also interested in shallow lakes and wetlands (including bogs and temporary lakes). We carried out studies on the trophic structure and their dynamics in relation with global changes. Also we study the impact of fish introduction in systems with two trophic levels.

The Andean region contains many streams that constitute the headwaters of the main rivers that cross the Patagonia steppe. The Nothofagus forest densely covers headwaters and provides allochthonous organic matter to the streams, therefore deforestation can cause dramatic effect on the aquatic system. Experimental studies have shown that leaf litter decay rates from autochthonous and exotic tree species differ markedly, supporting the idea that the introduction of Pinus modifies the quantity and quality of organic matter inputs. Currently we carry out studies on the interaction detritus-microorganisms-macroinvertebrates in relation to local and global changes and the impact of salmonids introduction.