包头南海子湿地三种鹭鸟羽毛与环境中重金属含量的关系

于2016年7至10月采用电感耦合等离子体发射光谱法(ICP-OES),测定了内蒙古包头南海子湿地繁殖期过后的白琵鹭(Platalea leucorodia)、苍鹭(Ardea cinerea)和夜鹭(Nycticorax nycticorax)3种鹭鸟初级飞羽及环境因子(水、土壤、食物)中As、Cd、Cr、Cu、Ni、Pb、Zn、Fe、Mn、Hg 10种重金属的含量,采用单因素方差分析方法比较了不同鹭鸟种类羽毛重金属含量差异,并通过生物富集系数及Pearson相关性检验分析了羽毛与环境因子间重金属含量之间的关系,以揭示包头南海子湿地环境中重金属污染现状及生物富集特征。结果表明:(1)被检测的10种重金属中,As、Cd、Cr、Cu、Pb、Zn、Hg 7种元素在湿地环境中均已超标,尤其土壤中Fe、Zn、Cu已达到重度污染的程度。(2)不同重金属元素在鹭鸟羽毛中的含量存在差异,其中Fe元素在白琵鹭羽毛中的含量水平最高(388.77 mg/kg),Cd元素在夜鹭羽毛中的含量最低(0.12 mg/kg)。在鹭鸟羽毛中重金属含量由高至低的顺序分别为,白琵鹭Fe、Zn、Mn、Cu、Hg、Cr、Ni、Pb、As、Cd,苍鹭Zn、Fe、Cu、Cr、Ni、As、Mn、Hg、Pb、Cd,夜鹭Zn、Fe、Mn、Cu、Ni、Pb、Hg、Cr、As、Cd。除Pb和Cd元素外,其他8种元素含量在3种鹭鸟羽毛中的含量种间差异显著。(3)相关分析表明,鹭鸟羽毛中的重金属含量与环境因子中的重金属含量显著相关且呈现富集特征,为此可作为监测当地环境污染的指示性材料。

Relationship of Heavy Metal Contents between the Feathers of Three Ardeidae Species and Environment at the Nanhaizi Wetland in Baotou City

The Baotou Nanhaizi wetland is an important part of the Yellow River wetland ecosystem, served as a stopover for many migratory birds and water source for living in Baotou City. However, in recent years, the quality of wetland ecological environment has been declining due to effluence of industrial wastewater. Bird feathers can serve as indicators for environmental monitoring and indirectly help to assess a wetland ecological environment. After the breeding season, primary feathers of three heron species, the Eurasian Spoonbill (Platalea leucorodia), the Grey Heron (Ardea cinerea) and the Black-crowned Night Heron (Nycticorax nycticorax), and environmental factors (e.g., water, soil and food) were collected from the Nanhaizi wetland in Baotou, Inner Mongolia. In November, 2016, the heavy metal content was measured using an inductively coupled plasma optical emission spectrometer (ICP-OES) for 10 elements, namely, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, and Hg. Differences of heavy metal contents of the feathers were compared using one-way ANOVA, the relationship of heavy metal contents between the feathers of three Ardeidae species and environment were analyzed by bioconcentration factor and Pearson correlation test to examine the status of heavy metal pollution and its enrichment characteristics in the Nanhaizi wetland. We found that: (1) The levels of As, Cd, Cr, Cu, Pb, Zn, and Hg had exceeded the standard in wetland environment, especially in soil, Fe, Zn and Cu had reached the level of severe pollution. (2) The remnants of different heavy metal elements in heron feathers varied among different species, with the highest being Fe of the Eurasian Spoonbill (388.77 mg/kg), and the least being Cd of the Black-crowned Night Heron (0.12 mg/kg). The decreasing order of heavy metal contents in the feathers of Eurasian Spoonbill was as follows: Fe > Zn > Mn > Cu > Hg > Cr > Ni > Pb > As > Cd, with Zn > Fe > Cu > Cr > Ni > As > Mn > Hg > Pb > Cd for the Grey Heron and Zn > Fe > Mn > Cu > Ni > Pb > Hg > Cr > As > Cd for the Black-crowned Night Heron. The levels of all detected elements (except Pb and Cd) differed significantly among the three species. (3) Pearson correlation analysis showed that the heavy metal contents in heron feathers were significantly correlated with that in the environment, and some metal elements were enriched in the feathers. In conclusion, bird feathers can be used as an indicator to monitor the local environmental pollution with the aim of providing a scientific basis for local governments to carry out assessments of the environment.