扎龙湿地系统的重金属富集特征及对水禽的影响

Heavy Metal Accumulation and Influence on Waterfowl in Zhalong Wetland

利用野外采集到的湿地底泥、水体以及栖息水禽的附属物(羽毛、蛋壳和粪便)样品,研究了扎龙湿地系统中Cr、Pb、Cd、Zn和Cu共5种重金属元素质量分数以及潜在生态风险评价。结果表明:人为活动对扎龙湿地系统重金属的富集有很明显的影响。研究区水体除Cu和Zn为II类水或者I类水质标准,Pb、Cr以及Cd都是V类,且靠近人类活度频繁区域底泥中重金属元素达到强污染程度,而与核心区相毗邻的样点污染程度较轻。底泥中Cd的生态风险指数的平均值为7.09,是研究区底泥中主要污染因子。扎龙湿地重金属富集已经影响到该区域大型水禽生态健康。扎龙湿地栖息和繁殖的常见水禽中都不同程度的富集了一定的重金属含量,且附属物中重金属质量分数为Zn>Cr>Pb>Cu>Cd,但是除了Cu元素外其它4种元素重金属质量分数已经超标且Cd超标最严重。对同一种水禽其不同附属物所超标程度不一致,表现为羽毛富>粪便>蛋壳。

Outer tissues of wild water fowl （feather, eggshell and feces） inhabited m Zhalong wetland were collected to investigate the content of five typical heavy metals in substrate of Zhalong wetland and its potential ecological risk was assessed. Results showed Zhalong Wetland is obviously affected by local human disturbance. The level of Zn and Cu belongs to Level I and II according to water quality standard of China, respectively. The levels of Pb, Cr and Cd in water body belong to Level V. In addition, the pollution level of heavy elements reaches strong pollution level near the local resident, but very weak level near to core zone of wetland. The mean ecological risk index of Cd is 7.09, and Cd is the main pollution factor for heavy metal pollution in study area. In Zhalong Wetland, wild water fowl accumulates the heave metal, and the heavy metal content in appendage is ranked as ： Zn〉Cr〉Pb〉Cu〉Cd. The high level of heavy metal accumulation in sediment has affected the ecological health of large water fowl in study area. The contents of four element are serious above the health standard except Cu, especially the content of Cd. The degree of excessive heavy metal in appendages of wild water fowl is ranked as： feather〉 feces〉egglshell.