Influence of the anthropization on the quality of water bodies of medium order associated to rural landscapes of the Paraná River basin (Argentina ),

PELUSO, LETICIA; DEMETRIO, PABLO M.; CONSTANZA BERNASCONI; APRIGLIANO NATALIA; RIMOLDI, FEDERICO

Cartagena

Congreso; SETAC Latin America 13th Biennial Meeting; 2019

Originally, rural landscapes were considered geographic areas where anthropization was almost exclusively a result of agriculture and/or livestock (A/L) activities. At present, while these activities continue to be predominant in those areas, urbanization and industrialization (U/I), have been assuming greater relevance, turning the rural areas into environmentally complex sectors.Therefore, the challenge of the environmental sciences is to find diagnostic strategies to assess the environmental impacts of this new scenario. Since surface water bodies are the final recipients of the pollutants generated in a basin, the study of water and bottom sediment quality is a informative approach to assessing the general environmental status of an area. Within this context, the objective of this study-- undertaken in the upper and middle sectors of the Argentine Paraná-River basin--was to evaluate the environmental impact of anthropization on the water and sediment quality of water bodies of middle orderassociated with rural landscapes. Sampling sites corresponding to the mouths of tributaries of the Paraná River were selected. Before the sampling campaign, the level of anthopization of each SS was estimated from aspects related to U/I and A/L activities. At each SS, general parameters of water quality were measured in situ and water and sediment samples taken for physical, chemical, microbiological and ecotoxicological assessment. The samples' toxicity was evaluated by a battery of standardized bioassays (Daphnia magna, Hyalella curvispina, and Lactuca sativa). The frequency of bioassays that shown significant effects respect to the control correlated strongly and positively with anthropization. Lactuca sativa was sensitive to pollutants of agricultural origin, while the crustaceans provided consistent responses to the U/I pollutants. The combination of U/I and A/L activities increased the toxicologic complexity of the water bodies, producing in general greater adverse effects. Although, in the rural areas the U/I activities represented a scale notably small in relation to A/L, the contribution of that activity to the deterioration of the toxicologic quality of water bodies appeared significant.