IBBEA   24401
INSTITUTO DE BIODIVERSIDAD Y BIOLOGIA EXPERIMENTAL Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Impact of glyphosate on aquatic ecosystems: experimental analysis using periphytic diatoms (Laguna del Cisne, Uruguay)
Autor/es:
MEERHOFF, M; CORRALES-MARTÍN, N.; ANTONIADES, D.; MAIDANA N. I.
Lugar:
QUEBEC
Reunión:
Simposio; 24 TH INTERNATIONAL DIATOM SYMPOSIUM; 2016
Institución organizadora:
ISDR
Resumen:
Freshwater ecosystems areessential for the support and development of human societies, and are verysensitive to anthropogenic impacts. The intensification of agriculturalpractices is a global phenomenon which implies a great use of fertilizers andagrochemicals. After application to crops, these chemicals may enter aquaticecosystems through surface runoff and groundwater inputs. Laguna del Cisne(Canelones, Uruguay) is a lake that has been used, since 1971, as a source ofwater by the state agency (OSE) responsible for supplying the country withdrinking water. However, intensive agriculture in this basin has also beenpresent for the past two decades. Moreover, its preservation is suggested as apriority since there are no alternative sources of drinking water in the area.Glyphosate is the active ingredient of the most widely used herbicide aroundthe globe. It is often considered relatively safe for biota, although severalstudies have found adverse effects of both glyphosate and its metabolites, andsurfactants on microbial communities, invertebrates, amphibians, fishes, andperiphyton. It has also been recently classified as a possible carcinogen bythe World Health Organization. The objective of this studywas to determine the effect on a natural periphytic diatom community of theexposure to different concentrations of glyphosate. A bioassay was carried outfor fifteen days, where periphytic diatoms, grown in situ, were exposed to 4concentrations of glyphosate (1, 3, 5, and 10 mgL-1), in addition to a controlsample without glyphosate added. It was done in two seasons: winter 2014 andspring 2015 and samples were taken every five days. The species composition ofthe diatom community was similar for the two seasons; however, the percentcomposition of the dominant assemblages differed greatly. In winter, Melosiravarians was the most abundant species in every sample, while the composition inspring was more evenly distributed. While the spring experiment is still beinganalyzed, PCA and Multilevel pattern analysis of winter samples have shownclear changes in the community with increasing glyphosate concentrations. Inparticular, Nitzschia sp 1 appears to be sensitive to increasing glyphosateconcentrations while Fistulifera sp. appears as tolerant.