Paracampo Ariel, Marrochi Natalia, GarcÍa Ignacio, Maiztegui TomÁs, Carriquiriborde Pedro, Bonetto Carlos, Mugni HernÁn
Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA), CONICET-CCT La Plata-UNLP, Boulevard 120 y 62, Nº 1437, 1900, La Plata, Buenos Aires, Argentina.
Centro de Investigaciones del Medioambiente (CIM), CONICET, UNLP, Boulevard 120 Nº 1489, 1900, La Plata Buenos Aires, Argentina.
An Acad Bras Cienc. 2020 Jun 12;92(2):e20190476. doi: 10.1590/0001-3765202020190476. eCollection 2020.
The present study reported the effect of natural and anthropic environmental variables on the fish assemblages in the pampean streams, in the coastal strip along the Río de la Plata, Buenos Aires province, Argentina. Five streams were sampled at 12 sites surrounded by land devoted to different uses. A correspondence analysis sorted the streams into two groups: a less impacted group formed by sites surrounded by livestock- raising pastures and a more impacted one passing through urban sites and including a stream adjacent to a modest rural urbanization with a dairy in the stream's basin. The nutrient concentrations were significantly higher in the more impacted group; with species richness, diversity, abundance, and biomass being significantly lower. A canonical-correspondence analysis linked the more impacted sites to high concentrations of soluble reactive phosphorus and impoverished fish assemblages, composed of species tolerant to environmental pollution. On the other hand, sites with higher oxygen concentrations and pH were related to richer assemblages pointing to good environmental conditions at the sites surrounded by livestock-raising pastures. The downstream sites on the less impacted streams contained fish assemblages in which the juvenile stages of species corresponding to the Río de la Plata were dominant.
本研究报告了自然和人为环境变量对阿根廷布宜诺斯艾利斯省拉普拉塔河沿岸沿海地带潘帕斯溪流中鱼类群落的影响。在五个溪流的12个采样点进行了采样,这些采样点周围土地用途各异。对应分析将溪流分为两组:一组受影响较小,由被畜牧牧场环绕的采样点组成;另一组受影响较大,流经城市区域,包括一条与流域内有奶牛场的适度乡村城市化地区相邻的溪流。受影响较大的组中营养物质浓度显著更高;而物种丰富度、多样性、丰度和生物量则显著更低。典范对应分析将受影响较大的采样点与高浓度的可溶性活性磷以及由耐环境污染物种组成的贫瘠鱼类群落联系起来。另一方面,氧气浓度和pH值较高的采样点与更丰富的群落相关,这表明被畜牧牧场环绕的采样点环境条件良好。受影响较小的溪流下游采样点的鱼类群落中,与拉普拉塔河相对应的物种幼体阶段占主导地位。