Iwasaki Yuichi, Kagaya Takashi, Miyamoto Ken-Ichi, Matsuda Hiroyuki
Graduate School of Environment and Information Sciences, Yokohama National University, 79-7, Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
Environ Toxicol Chem. 2009 Feb;28(2):354-63. doi: 10.1897/08-200.1.
We examined the influence of heavy metal pollution from an abandoned mine on benthic macroinvertebrates, at population and community levels, and the potential amount of food available for drift-feeding fish in northern Japanese streams. We studied multiple polluted and unpolluted sites with similar longitudinal positions to avoid problems caused by upstream-downstream comparisons. The ranges of zinc, copper, cadmium, and lead concentrations among the study sites were 5 to 812 microg/L, less than 0.12 to 5.2 microg/L, less than 0.0026 to 4.9 microg/L, and 0.1 to 18.6 microg/L, respectively. The abundance of several populations and community metrics showed a significant negative response to heavy metal pollution. Mayfly diversity and abundance was relatively sensitive to heavy metal pollution. In addition, the biomass of groups of macroinvertebrate taxa that are highly available for salmonids were significantly reduced at metal-polluted sites; this decrease in the most highly available group was noticeable (99% at the heavily polluted upper sites and 69% at the moderately polluted lower sites in spring). These results suggest that we should consider the indirect effect of pollution on food availability for the conservation of fish populations that depend on drifting macroinvertebrates.
我们在种群和群落水平上研究了日本北部溪流中废弃矿山的重金属污染对底栖大型无脊椎动物的影响，以及可供滤食性鱼类食用的潜在食物量。我们研究了多个纵向位置相似的污染和未污染地点，以避免上下游比较带来的问题。研究地点中锌、铜、镉和铅的浓度范围分别为5至812微克/升、低于0.12至5.2微克/升、低于0.0026至4.9微克/升和0.1至18.6微克/升。几个种群的丰度和群落指标对重金属污染表现出显著的负面反应。蜉蝣的多样性和丰度对重金属污染相对敏感。此外，鲑科鱼类极易获取的大型无脊椎动物类群的生物量在金属污染地点显著降低；在春季，这种极易获取的类群的减少很明显（在重度污染的上游地点为99%，在中度污染的下游地点为69%）。这些结果表明我们应该考虑污染对食物可获得性的间接影响，以保护依赖大型无脊椎动物漂流物的鱼类种群。
