United States Fish and Wildlife Service, 620 South Walker Street, Bloomington, IN 47403, USA.
Arch Environ Contam Toxicol. 2013 Aug;65(2):286-99. doi: 10.1007/s00244-013-9889-1. Epub 2013 Apr 21.
Stream fish assemblage structure and function were examined for significant response along a polychlorinated biphenyl (PCB) gradient from two PCB-contaminated streams (Clear Creek and Richland Creek watershed) at three locations and a control stream (Little Indian Creek), Indiana, USA. Fish were sampled in the summer months of 1995 and from 1999 to 2002. 51 fish assemblage attributes-including structure (i.e., fish composition) and function (i.e., trophic, reproductive, condition guilds), biomass, and index of biotic integrity (IBI) metric scores-were evaluated for significance according to an increasing PCB gradient. Eight biomass attributes of fish assemblages decreased with increasing PCB concentration: number of species biomass, number of sunfish biomass, percent sunfish biomass, number of sucker biomass, percent sucker biomass, biomass of sensitive species, percent sensitive species biomass, and percent carnivore biomass. Three biomass attributes increased with PCB concentration: percent minnow biomass, percent pioneer species biomass, and percent tolerant species biomass. Seven species composition and relative abundance characters decreased with increasing PCB concentration: number of species; number of darter, madtom, and sculpin; number of darter; number of sunfish; number of sucker; number of sensitive species; and percent individuals as carnivores. Percent individuals as pioneer species increased with increasing PCB concentration. Two IBI metrics, percent individuals as headwater species and number of minnow species, increased as PCB concentrations increased, whereas number of sucker species and percent individuals as pioneer species decreased with increasing PCB concentration class. We observed a direct response between decreased relative abundance and biomass of carnivores and increased relative abundance minnows as the PCB gradient increased. Total IBI score did not detect subtle changes to the fish community that were observed along a PCB gradient, whereas diagnostic analysis of the individual metrics did.
研究了来自美国印第安纳州两个受多氯联苯（PCB）污染的溪流（清澈溪和里奇兰溪流域）三个地点和一个对照溪流（小印第安溪）的 PCB 浓度梯度上的溪流鱼类群落结构和功能的显著响应。鱼类于 1995 年夏季和 1999 年至 2002 年期间进行采样。根据 PCB 浓度递增梯度，评估了 51 个鱼类群落属性，包括结构（即鱼类组成）和功能（即营养、繁殖、状况 guild）、生物量和生物完整性指数（IBI）度量得分的显著性。随着 PCB 浓度的增加，8 个鱼类群落生物量属性下降：物种数量生物量、太阳鱼数量生物量、太阳鱼比例生物量、吸盘数量生物量、吸盘比例生物量、敏感物种生物量、敏感物种比例生物量和肉食者生物量比例。随着 PCB 浓度的增加，有 3 个生物量属性增加：小鱼比例生物量、先锋物种比例生物量和耐受物种比例生物量。随着 PCB 浓度的增加，有 7 个物种组成和相对丰度特征下降：物种数量；达氏鱼、盲鱼和杜父鱼数量；达氏鱼数量；太阳鱼数量；吸盘数量；敏感物种数量；以及作为肉食者的个体比例。作为先锋物种的个体比例随着 PCB 浓度的增加而增加。随着 PCB 浓度的增加，两个 IBI 度量，即作为上游物种的个体比例和小鱼种类数量，增加了，而作为吸盘物种的个体比例和作为先锋物种的个体比例随着 PCB 浓度类别的增加而减少。随着 PCB 梯度的增加，我们观察到肉食者相对丰度和生物量的减少与小型鱼类相对丰度的增加之间存在直接的响应关系。总 IBI 得分没有检测到在 PCB 梯度上观察到的鱼类群落的细微变化，而个别指标的诊断分析则做到了这一点。
