Ecotoxicological Bioassays with the microalga Pseudokirchneriella subcapitata in lotic ecosystems and impact of metals using confocal fluorescence microscopy techniques

Abstract

A rapid and simple ecotoxicological bioassay allows a reliable estimation of state of the lotic ecosystems from Camana, Majes and Colca watershed located in region Arequipa (Peru) in six sampling points (Taparza, Grande, Majes1, Majes2, Camana1 and Camana2) by studying growth inhibition of the microalga Pseudokirchneriella subcapitata at 24, 48 and 72 hours and Mean Effective Concentration (EC₅₀), at 72 hours compared to National Environmental Quality Standards (EQSs) and water quality guidelines of the World Health Organization (WHO). Observing that in the sampling points of Majes1 and Majes2 surpassed the values of thermotolerant coliforms, Aluminum, Manganese, Iron and Total Suspended Solids (TSS), compared to the values of EQSs and water quality guidelines of the WHO, with an EC₅₀ in the Sampling stations of Majes1 and Majes2 categorizing them as moderately toxic. In this article, fluorescence confocal microscopy techniques were used to evaluate the impact of metals that exceeded the EQSs and WHO, proposing a model as the application of these microscopic techniques, opening wide perspectives, for future studies of metal ecotoxicity.