Bioindicators of water quality in the lower reaches of the Ocoña river basin, Arequipa department, Peru, using epilithic diatoms and their relationship with some environmental parameters

Motta Mamani J.C.; Ranilla Falcón C.A. · Revista Internacional de Contaminacion Ambiental (2024) · DOI: 10.20937/rica.54368

Resumen

The species richness and community structure of an epilithic diatom community and their relationship with physical, chemical and microbiological parameters in the lower reaches of the Ocoña river basin, Arequipa Department, Perú, were determined at three sampling points in January, May, and October 2019. Fifty-two taxa of the Bacillariophyta division were identified. Of the total taxa, 12 had a relative abundance greater than 2% and were used for canonical correspondence analysis. The highest species richness (39) occurred in October. The H’ diversity values (2.04 to 2.45 bit/cel) for January and October represent a community with normal diversity; while the values registered in May (0.51 to 1.58 bit/cel) are associated with low diversity. According to the Simpson Index, the highest dominance (0.18) occurred in May and was represented by Nitzschia inconspicua; equity (J) showed a uniform distribution in the diatom community in January (63%) and October (69%). From the canonical correspondence analysis, the taxa Diatoma moniliformis, Melosira varians, and Nitzschia palea presented a positive relationship with the environmental parameters pH, hardness, SO4–2, P, K, Na, and Mg, while Cocconeis placentula exhibited a positive correlation with pH, hardness, Ca, Mg, and Na. Likewise, Epithemia sorex, Nitzschia sp.1, and Ulnaria ulna showed a positive relationship with the highest Fe concentrations, while N. inconspicua was positively related to thermotolerant coliforms.

Instituciones: Universidad Nacional de San Agustín de Arequipa