Evaluation of water quality meachiche river (Falcon state-Venezuela), using biotic indexes

Abstract

Human activity continually affects the quality of aquatic ecosystems; therefore, there is interest in knowing the
degree of pollution and establishing water quality criteria that allow covering the needs of use of the resource. The present study evaluated the changes in the water quality of Meachiche river, in relation to effect of anthropogenic activities, using benthic macroinvertebrates as bioindicators, complemented by physicochemical analyzes. Once a month, nine physicochemical variables and four hydrological variables were measured in three sampling sites during the months of June - September 2010. The macroinvertebrates were collected with a Surber net, preserved with 4% formaldehyde and transported to laboratory. The Shannon-Wiener diversity index (H’), and biotic indices IBMWP, EPT and FBI were applied. A total of 2 537 macroinvertebrates were captured,
belonging to 10 orders and 25 families. The sampling site located downstream had the highest abundance of Physidae (Mollusca: Gasteropoda), classified by FBI as low quality waters, upstream sites were classified from regular to good quality. Sites studied were classified by EPT and IBMWP as regular or acceptable quality. Water was classified according to Decree 883 (1995) as subtypes 1A and 1B.