Relationships between aquatic invertebrate assemblages and environmental quality on saline wetlands of an arid environment

Abstract

Wetlands are ecosystems with great ecological value due to their extraordinary biodiversity and the ecosystem services they provide. Saline wetlands have specific biological attributes and conservation significance due to the particular fauna they hold. On this study, we analyzed invertebrate assemblages, the conservation state and environmental quality of Desaguadero-Salinas del Bebedero Wetlands, in a RAMSAR site of central Argentina. Water samples for physical-chemical analysis and samples of aquatic invertebrates were taken at seven sites. A Simplified Index of Water Quality (SIWQ) and the Index of Conservation State of Lentic Somers Ecosystems (CSLSE) were applied. Forty-four invertebrate taxa were identified in a community characterized by low diversity, and high abundance of salinity tolerant groups. Some invertebrate metrics showed strong associations with concentrations of majoritarian ions in water, CSLSE and SIWQ. Five invertebrate metrics of richness and diversity, three of assemblage composition and three related to feeding groups displayed the best performance in explaining significant differences among sites. Our findings reinforce the use of aquatic invertebrates on biological assessments of human impacts in saline water bodies that are scarce worldwide; and enhance the knowledge of wetlands located in arid regions, extremely fragile habitats that should be deeply studied and understood at a global scale.