Summer phytoplankton and hydrochemical factors of the crater lake Laguna Azul (Santa Cruz, Argentina)

MESSYASZ, B.; MAIDANA, N. I.; LÜCKE, A.; MAYR, C.

Poznañ-£agów-Subice.

Congreso; 25th International Phycological Conference. Algae and their changes over time.; 2006

Physical and chemical characteristics of depth profiles in the water column of Laguna Azul (Southern Patagonia, Argentina) were monitored in four subsequent summers (2002-2005). Due to its sheltered position in a volcanic crater, Laguna Azul is dimictic and stratified in summer, unlike most other lakes in the Southeastern Patagonian steppe. Summer stratification is apparent also in most of the monitored parameters. The summer seasons were characterized by a low phytoplankton biomass, high diversity assemblage of mostly nanoplanktonic species. A shift in the diatom assemblages was observed during the monitoring period which is possibly related to shifts in nutrient availability.