IIMYC   23581
INSTITUTO DE INVESTIGACIONES MARINAS Y COSTERAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The expansion of agricultural frontiers and its consequences on the environment. The case of Argentina during last decades.
Autor/es:
MENONE, MIRTA LUJÁN; MIGLIORANZA, KARINA SILVIA BEATRIZ; WUNDERLIN, DANIEL ALBERTO
Lugar:
Berlin
Reunión:
Congreso; 6th SETAC World Congress 2012; 2012
Institución organizadora:
SETAC
Resumen:
The expansion of agricultural frontiers and its consequences on the environment. The case of Argentina during last decades. Abstract: The agricultural expansion and intensification in South America, particularly in Argentina, Brazil and Uruguay, has triggered negative changes in the environment. The negative effect of human intervention on habitat and biodiversity would have increased and the water-use efficiency decreased. However erosion and pollution risk are today lower than those of the mid-20th century. Regarding agrochemicals, quantities and qualities of pesticides used in Argentina vary with the productive system. Pedological and climatic characteristics of the Argentinean regions determine the kind and extension of agricultural activities. Extensive soybean and wheat productions are concentrated on the Rolling Pampa region and account for the 80% of the total arable land of the country. This system is based on the direct seeding technique with the application of the herbicide glyphosate, and technical endosulfan and a-cypermethrin as insecticides. On the other hand, Patagonian agriculture is almost exclusively based on the fruit and wine production concentrated mainly on the Rio Negro watershed. The historical and current use of pesticides in the area is reflected on the occurrence of organochlorine pesticides in biotic and abiotic matrices from the Rio Negro Valley with a clear predominance of residues of DDTs followed by endosulfans. The intensive and increased agriculture developed in Argentina during the last 20 years lead to different effects on biota. Mass mortality of Swainson’s hawks occurred in Argentina due to monocrotophos during 1995–96 and recent investigations in the Pampas showed that bird species richness tends to correlate negatively with annual crops. Non- target species from other ecosystems like the aquatic could suffer the negative consequences of the pesticides. Concentrations of chlorpyrifos and cypermethrin that exceeded the water quality criteria for freshwater environments have been detected in runoff and stream water of small agricultural streams in the main soybean area of Argentina; associated to 100% mortality of aquatic macroinvertebrates. Environmentally relevant concentrations of endosulfan have been demonstrated that exert oxidative stress, genotoxicity and histological damage in native fish and wetland macrophytes in laboratory experiments. Therefore, residues of this pesticide in freshwater ecosystems are expected to damage wildlife at organism or even more at population level.