Zooplankton and limnological parameters dynamics in a mesosaline lake of a protected area in the semi-arid Pampa of Argentina

Abstract

Most of the mesosaline lakes in the semiarid central Pampas have a high anthropogenic influence. The aim was to determine the variation in limnological and zooplankton parameters of a mesosaline lake with little human impact, the West Lake of the Parque Luro Reserve during a year. Monthly samples were taken between 2014 and 2015. The mean depth and salinity were 0.66 m and 29.33 g/L, respectively. The transparency was total; the light reached the bottom and favored the growth of the macrophyte Ruppia cirrhosa. Two cladocerans, three copepods, and eight rotifers were registered. Among crustaceans, autochthonous halophilic species were found (Daphnia menucoensisand Boeckella poopoensis). Zooplankton density was 20 to 100 times lower than that of other Pampeanlakes, probably due to the presence of the macrophyte, which distinguishes this lake from others in the region