Resumen

SALUSSO, María Mónica  y  MORANA, Liliana Beatriz. Structure and composition of phytoplankton from Mina Pirquitas, Jujuy, Argentina. Rev. Mex. Biodiv. [online]. 2015, vol.86, n.3, pp.711-718. ISSN 2007-8706.  https://doi.org/10.1016/j.rmb.2015.05.008.

Mining activities produce extreme environmental conditions in aquatic systems because they tend to contain unusually high concentrations of heavy metals as their solubility increases markedly while pH decreases. In the Andean region of Jujuy province at 4,200 m asl, the exorheic system of Orosmayo River (Ajedrez) is affected by the extraction of silver in Mina Pirquitas. The structure and composition of phytoplankton in 5 tributaries was evaluated by sampling in Autumn and Spring for the 2011-2013 period, using standard techniques. Phytoplankton abundance was higher in the rainy season, especially in March, 2011 in all sites, with a maximum of 828 ind.ml−1 in Ajedrez River. The physicochemical data revealed acidic conditions in the River Pircas (pH between 2.6 and 3.9) with high concentrations of Al3+, and Fe3+. This site showed lower density values (176 ind.ml−1), diversity (2.67) and species richness (average 11). Diatoms were affected by the pH in the River Pircas, because their percentage of representation was low (18.48%), with a predominance of green algae (52%), mainly represented by phytoflagellates (Chlamydomonas, Dunaliella) and filaments (Klebsormidium, Spirogyra, Zygogonium, Ulothrix) , among others.

Palabras llave : Puna; Algae; South America; Lotic system; Orosmayo.