Influencia de los cambios ambientales sobre las poblaciones de peces en ecosistemas lénticos de la llanura pampeana (Argentina)

ALEJANDRA VANINA VOLPEDO; ESTEBAN AVIGLIANO; ALICIA FERNANDEZ CIRELLI

Evaluación de los cambios de estado en ecosistemas degradados de Iberoamerica

Red CYTED

Año: 2013; p. 38 - 52

The Pampa in Argentina is one of the Great Plains worldwide, whose low slope since there are numerous lentic water bodies, in which the influence of environmental changes is relevance. These changes are due to historical climate variability (humid and dry periods), yearly seasonal changes, and changes in the land use for intensification of agricultural activities. These wet and dry cycles produce changes in the water quality in ecosystems and biota. In these water bodies, the most important commercial species is the silverside (Odontesthes bonariensis), which is the second largest freshwater fishing resource in the province of Buenos Aires. In this context, this work proposes an analysis of environmental influence in water bodies of pampean plain (Laguna de Chascomús and Lake Chasicó) with different physico-chemical, biological and geomorphological characteristics and their impact on different levels of biological organization (individuals, population and communities) related to the silverside. The results show that environmental changes in different temporal scale, which are reflected in changes in the communities due to disturbances in the functioning of the trophic patterns are observed in both water bodies (decrease in items food -macrozooplankton and increase in phytoplankton); population changes (decrease in abundance of silverside) and changes in individuals (morphological and morphometric alterations in anatomical structures such as otoliths).