Recovery of a mining-damaged stream ecosystem

This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu), arsenic (As), and cobalt (Co) into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be found in 40 km of mine-affected reaches of Panther Creek downstream of the metals contaminated tributaries, Blackbird and Big Deer Creeks. Efforts to restore water quality began in 1995, and by 2002 Cu levels had been reduced by about 90%, with incremental declines since. Rainbow Trout (Oncorhynchus mykiss) were early colonizers, quickly expanding their range as areas became habitable when Cu concentrations dropped below about 3X the U.S. Environmental Protection Agency’s biotic ligand model (BLM) based chr...本研究报道了一段与美国爱达荷州中部鲑鱼河支流潘瑟溪（Panther Creek）受采矿影响河段水质改善过程相关的底栖大型无脊椎动物（benthic macroinvertebrate）群落与鱼类种群长达30余年的变化记录。美国爱达荷州中部的布莱克伯德矿（Blackbird Mine）曾开展采矿与选矿作业，向支流排放铜（Cu）、砷（As）与钴（Co），对潘瑟溪造成了严重破坏。20世纪60年代至80年代，在受金属污染的支流布莱克伯德溪与大鹿溪下游的40公里受采矿影响的潘瑟溪河段中，未发现鱼类，仅存极少数水生无脊椎动物。水质修复工作于1995年启动，截至2002年，铜浓度已降低约90%，此后浓度持续小幅下降。虹鳟（Oncorhynchus mykiss）为早期拓殖物种，当铜浓度降至约为美国环境保护局（U.S. Environmental Protection Agency，EPA）基于生物配体模型（biotic ligand model，BLM）制定的标准3倍以下时，适宜栖息的区域不断扩大，其分布范围迅速扩张。