ZOOPLANKTON DIVERSITY OF A PROTECTED AND VULNERABLE WETLAND SYSTEM IN SOUTHERN SOUTH AMERICA (LLANCANELO AREA, ARGENTINA)

D'AMBROSIO, D. SABINA; CLAPS, MARIA CRISTINA; GARCIA, ADRIANA

International Aquatic Research

Springer

Año: 2016 vol. 8 p. 65 - 80

2008-4935

Inarid regions, climatic conditions exert a great control on the aquatic systemspresent, but recent changes in climate have produced an enhanced salinizationof the aquatic environments located there. Consequently, a major reduction inbiodiversity would be expected in those wetlands that were originally freshwater. Salinity is a principal cause of reduced biodiversity particularly inzooplankton because few of those species can adapt to the salt pressure ofsaline environments. Therefore, the aim of this study was to gain essentialinformation on the diversity of aquatic invertebrates in Llancanelo basin byfocussing the analysis on the zooplankton community and exploring seasonal andspatial differences in the zooplankton assemblages of this vulnerable wetlandsystem within an arid region of Argentina. Seasonal samples were taken at 9sites in the basin (a shallow lake, 4 springs, streams, and the MalargüeRiver). A total of 45 species were identified. The zooplankton abundance in thelake displayed a clear seasonal contrast and was higher than that recorded inthe springs and lotic environments.Boeckella poopoensis, Fabrea salina, and Brachionus plicatilis predominated in the lake, indicating theirhalophilia. The presence of the crustaceans Alonasp., Macrocyclops albidus, and Paracyclops fimbriatus was restricted tothe springs; whereas Notholca labisand Notholca squamula were found onlyin running water. The zooplankton species richness in the Llancanelo area islow because of both the salt content in the lake and the irregularity offreshwater entry in all locations during the annual cycle.