PDF(Pubmed)
Abstract：
Detecting human impact on freshwater ecosystems is problematic without rigorous assessment of temporal changes. Assessments of mining impacts are further complicated by the strong influence of local catchment geology on surface waters even in unmined environments. Such influence cannot be effectively considered by using broad-scale reference frameworks based on regionalization and stream types. Using the BACI (Before-After Control-Impact) design, we examined the impact of mining discharges on freshwater algae and macroinvertebrate communities resulting from the rerouting of treated wastewaters through a pipeline to larger water bodies in Northern and North-Eastern Finland. Impacted sites and control sites were sampled 1 to 2 years before and 1 to 3 years after the pipelines became operational. Stream diatom communities recovered from past loadings upstream of the pipeline (which was no longer impacted by wastewaters) after rerouting of the wastewaters, while no changes downstream from the pipeline were detected. Upstream from the pipeline, diatom species richness increased and changes in relative abundances of the most common diatom taxa as well as in the overall community composition were observed. The effects of the pipeline were less evident for stream macroinvertebrate communities. There was an indication that regional reference conditions used in national biomonitoring may not represent diatom communities in areas with a strong geochemical background influence. Lake profundal macroinvertebrate communities were impacted by past loadings before the construction of the pipeline, and the influence of the pipeline was observed only as changes in the abundances of a few individual species such as phantom midges (which increased in abundance in response to discharges directed through the pipeline). Our results highlight the variable influence of mining discharges on aquatic communities. Statistically strong monitoring programmes, such as BACI designs, are clearly needed to detect these influences.
摘要：
如果不严格评估时间变化，检测人类对淡水生态系统的影响是有问题的。即使在未开采的环境中，由于当地集水区地质对地表水的强烈影响，对采矿影响的评估也变得更加复杂。通过使用基于区域化和流类型的大规模参考框架，无法有效地考虑这种影响。使用BACI（前后控制冲击）设计，我们研究了采矿排放对淡水藻类和大型无脊椎动物群落的影响，这些影响是通过管道将经过处理的废水改道到芬兰北部和东北部的较大水体。受影响的站点和控制站点在管道开始运营之前1至2年和之后1至3年进行采样。重新路由废水后，从管道上游的过去负载（不再受到废水的影响）中回收的硅藻群落，而没有检测到管道下游的变化。从管道上游，硅藻物种丰富度增加，并观察到最常见硅藻分类单元的相对丰度以及整个群落组成的变化。对于大型无脊椎动物群落，管道的影响不太明显。有迹象表明，国家生物监测中使用的区域参考条件可能并不代表地球化学背景影响强烈的地区的硅藻群落。在管道建设之前，深湖大型无脊椎动物群落受到过去负荷的影响，并且管道的影响仅在一些单个物种的丰度变化时观察到，例如幻影mid（响应于通过管道的排放而增加的丰度）。我们的结果强调了采矿排放对水生群落的可变影响。统计上强有力的监测方案，如BACI设计，显然需要检测这些影响。
