José Morábito

The nematode Caenorhabditis elegans as an integrated toxicological tool to assess water quality and pollution.

Determination of water quality status in rivers is critical to establish a sustainable water management policy. For this reason, over the last decades it has been recommended to perform integrated water assessments that include water quantities and physicochemical, ecological and toxicological tests. However, sometimes resources are limited and it is not possible to perform large-scale chemical determinations of pollutants or conduct numerous ecotoxicological tests. To overcome this problem we use and measure the growth, as a response parameter, of the soil nematode Caenorhabditis elegans to assess water quality in rivers. The C. elegans is a ubiquitous organism that has emerged as an important model organism in aquatic and soil toxicology research. The Tunuyán River Basin (Province of Mendoza, Argentina) has been selected as a representative traditional water monitoring system to test the applicability of the C. elegans toxicological bioassay to generate an integrated water quality evaluation. Jointly with the C. elegans toxic assays, physicochemical and bacteriological parameters were determined for each monitoring site. C. elegans bioassays help to identify different water qualities in the river basin. Multivariate statistical analysis (PCA and linear regression models) has allowed us to confirm that traditional water quality studies do not predict potential toxic effects on living organisms. On the contrary, physicochemical and bacteriological analyzes explain <62% of the C. elegans growth response variability, showing that ecotoxicological bioassays are important to obtain a realistic scenario of water quality threats. Our results confirm that the C. elegans bioassay is a sensible and suitable tool to assess toxicity and should be implemented in routine water quality monitoring.

The Transformation of the Oases of Mendoza (Argentina): How the Provincial Socio-spatial Structure Was Reversed by the Crises of the 1980s and 2000s

The oases of the Province of Mendoza , sited on the arid piedmont of the Argentinian Andes , have experienced some changes in their organisation, according to the civilisations that have cultivated these lands: Huarpes , Incas , Spanish colonisers and European migrants . Although these changes in societies transformed the agricultural orientation , the crises of the 1980s and 2000s did not radically change the typical Mediterranean landscape of such spaces. However, on the one hand they created a new type of landscape and, on the other hand, they had a deep impact on the socio-spatial and economic structures : former cores became secondary, and what used to be desert margins were developed until they became the new economic centre of the Province.