Patagonian ostracods and hydrochemical characteristics of Southern Patagonian lakes (Argentina): implications for paleoenvironmental reconstructions based on lacustrine records

RAMON-MERCAU, J.,LAPRIDA, C., MASSAFERRO, J., ROGORA, M., TARTARI, G., MAIDANA, N

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2012 vol. 692 p. 1 - 17

0018-8158

Hydrochemical data of 36 Southern Patagonian waterbodies is analyzed with respect to its relationship with water balance. In turn, data on the modern ostracod assemblages present in these waterbodies, together with Patagonian freshwater ostracod data published, is analyzed in order to characterize the species in terms of their hydrochemical preferences. The results obtained show that the ostracod Limnocythere rionegroensis is found in mesohaline waters (WA TDS = 9870 mg/l) with Na+ as the dominant cation and enriched in all major anions, which are typical of (ephemeral) lakes and ponds located in the Patagonian steppe. In contrast, the ostracods L. patagonica, Eucypris cecryphalium, Potamocypris smaragdina and Penthesilenula incae are restricted to low salinity (WA TDS up to 530 mg/l), bicarbonated waters enriched in Ca+2, Na+1 and Mg+2, a water type characteristic of lakes situated in ecotonal areas or at the base of the Andean range. Since these contrasting hydrochemical characteristics can be related to different precipitation regimes, these species are potentially useful as paleohydrological indicators. Other ostracods studied - Ilyocypris ramirezi, E. fontana and E. virgata - are found in waterbodies with widely differing hydrology, which limits their use as indicators with respect to those environmental parameters.