Abstract

MAMANI VILLALBA, Bethy Andy; BIAMONT ROJAS, Ivan Edward  and  CALSIN QUINTO, Brígida. Ecotoxicological Evaluation by means of bioassay with Daphnia Pulex in sediments of the Suches River, Cojata Peru-Bolivia Border, 2019. Fides Et Ratio [online]. 2021, vol.22, n.22, pp.191-215. ISSN 2071-081X.

Abstract Unregulated anthropogenic extractive activities discharge their wastes into water bodies without complying with mínimum standards and these metallic compounds present a toxicological potential when they sediment. The objective was to evalúate the ecotoxicity of heavy metáis in sediments of the Suches river by means of a bioassay with Daphnia pulex. This was developed in three phases: exploration of the study área, laboratory tests for heavy metáis and toxicological bioassay with Daphnia pulex. for the extraction of the elutreate, the sediment toxicity test protocol was used (Garmendia, et.al., 2009) and for the bioassay with Daphnia pulex, the methodology established in the Chilean Technical Standard (NCh2083. Ofl999) was applied. The concentration of heavy metáis in sediments of the Suches river (4 sampling points) and the toxicity of heavy metáis present in sediments on the species Daphnia pulexwere evaluated. The concentration where there is no observed eífect (NOEC) for MuSe-1 is 21.2 % (53 g/L), MuSe-3 is 32.2 % (80.5 g/L), MuSe-4 is 44.4 % (111.0 g/L), MuSe-5 is 57.3% (143.3 g/L) and the lowest observed eífect concentration (LOEC) for MuSe-1 is 30.4 % (76 g/L), MuSe-3 is 41. 0% (102.5), Muse-4 is 52.0 % (130.0 g/L), MuSe-5 is 67.6 % (169 g/L); the dose generating death at 50% of the exposed population (LC 50) for MuSe-1 is 37.5 % (93.6 g/L), MuSe-3 is 45.9 % (114.8 g/L), Muse-4 is 55.9 % (139.9 g/L), MuSe-5 is 63.8 % (159.4 g/L). Therefore, it is concluded that the sediments of the Suches river basin present toxic levéis.

Keywords : Daphniapulex; aquatic ecotoxicology; heavy metáis; mining; sedimente; Suches river..

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