Seasonal dynamics of a large, shallow lake, laguna Chascomús: the role of light limitation and other physical variables

ANA TORREMOERELL,; JOSE BUSTINGORRY,; ROBERTO ESCARAY,; HORACIO ZAGARESE

LIMNOLOGICA

Año: 2007 vol. 37 p. 100 - 108

0075-9511

The most conspicuous waterbodies in the Pampa region of Argentina are the so called “lagunas”.  A typical Pampean laguna may be described as a relatively large (100+ ha), permanent, shallow lake. Here we report the dynamics of laguna Chascomús, sampled weekly, from April 2001 to June 2003.  During the period, the lakes experienced three consecutive floods waves that affected the concentration of major ions and the optical signature of the dissolved organic matter.  Despite these hydrological alterations, laguna Chascomús was permanently limited by light.  Transparency was to a great extent controlled by the incident PAR irradiance.  We hypothesize that wind contributes to the permanent mixing of the lake, as well as to lessen the sedimentation losses of photoautothrophs.