Instituto de Limnología "Dr. Raúl Ringuelet" (CONICET-UNLP), Bv 120 n° 1437, CP 1900 La Plata, Argentina.
Grupo de investigación en Geología Ambiental (GIGA), Universidad Nacional de Avellaneda (UNDAV), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avellaneda, Argentina.
Sci Total Environ. 2021 Sep 1;785:147317. doi: 10.1016/j.scitotenv.2021.147317. Epub 2021 Apr 24.
Horticulture has greatly increased in Argentina in recent decades mainly due to increasing greenhouse utilization and agrochemical consumption, thus representing a threat to adjacent water bodies. Riparian wetlands, however, could attenuate agrochemical contamination. The present work therefore compared insecticide concentrations in bottom sediments in addition to sediment toxicity to the amphipod Hyalella curvispina and investigated the macroinvertebrate composition upstream and downstream from a natural wetland in a small stream draining a basin undergoing intense horticultural production. The wetland surface was covered by macrophytes, mainly Thypha sp., and the insecticide concentrations measured downstream from the wetland were significantly lower, at roughly 19% of the upstream values. The growth rates of H. curvispina were significantly higher when exposed to the sediments downstream from the wetland, while the macroinvertebrate-assemblage composition was significantly different upstream and downstream: the snail Pomacea canaliculata was the dominant species upstream while the amphipod H. curvispina was dominant downstream. Pomacea canaliculata is often the dominant species in the regional streams draining agriculture and horticultural basins. Hyalella curvispina is sensitive to pesticide toxicity and is often dominant in streams draining extensive livestock basins and within a biosphere reserve. We conclude that riparian wetlands effectively attenuate horticulture contamination in pampean streams and should therefore be preserved and restored.
近几十年来，阿根廷的园艺业有了很大的发展，主要是由于温室利用率和农用化学品消耗量的增加，这对邻近的水体构成了威胁。然而，河岸湿地可以减轻农用化学品的污染。因此，本研究比较了小河流中一个自然湿地上下游底泥中的杀虫剂浓度以及底泥对食蚊鱼（Hyalella curvispina）的毒性，并调查了一个正在进行集约化园艺生产的流域中一个自然湿地上下游的大型无脊椎动物组成。湿地表面被大型植物覆盖，主要是香蒲属植物，而从湿地下游测量到的杀虫剂浓度明显较低，约为上游值的 19%。当暴露于湿地下游的沉积物时，食蚊鱼的生长速度明显较高，而大型无脊椎动物的组成在上游和下游有明显的差异：蜗牛Pomacea canaliculata 是上游的优势种，而食蚊鱼（Hyalella curvispina）是下游的优势种。Pomacea canaliculata 通常是农业和园艺流域排水区域的溪流中的优势种。食蚊鱼（Hyalella curvispina）对农药毒性敏感，通常在排水广泛的牲畜流域和生物圈保护区内的溪流中占优势。我们得出结论，河岸湿地有效地减轻了潘帕斯河流域的园艺污染，因此应该得到保护和恢复。
