休渔期和捕捞作业期黄、渤海区沿海中心渔港表层海水重金属分布及生态风险评估

Distribution and ecological risk assessment of heavy metals in surface seawater of central fishing ports along the coast of the Yellow Sea and Bohai Sea during fishing off season and fishing season

为了弄清休渔期和捕捞作业期黄、渤海区沿海中心渔港表层海水重金属污染水平,本研究于2020年5月和10月在黄、渤海区沿海11个中心渔港采集水样,分析了Cu、Zn、Pb、Cd、Hg和As 6种重金属的浓度及污染特征,探讨了其主要来源,并评估了其生态风险。结果表明,休渔期Cu、Zn、Pb、Cd、Hg和As的浓度范围分别为1.26~4.46μg/L、4.10~22.72μg/L、1.18~16.76μg/L、0.54~7.80μg/L、0.02~0.08μg/L和0.02~0.86μg/L;捕捞作业期分别为0.60~4.62μg/L、4.92~10.61μg/L、0.16~2.95μg/L、0.14~2.95μg/L、0.03~0.11μg/L和0.16~1.37μg/L,休渔期和捕捞作业期各渔港的Cu、Zn、Pb、Cd、Hg和As浓度均值满足《海水水质标准》(GB 3097-1997)四类标准;黄海沿海中心渔港表层海水重金属浓度略低于渤海地区,与我国东海地区和南海地区相比,黄、渤海区Cu、Pb和Cd浓度处于较高水平,Zn和Hg浓度处于中等水平,As浓度处于较低水平。分析发现,休渔期和捕捞作业期Zn和As来自陆源,Cu来自陆源和船舶防污漆,表层海水Pb与大气沉降和燃料尾气有关。沿海中心渔港表层海水重金属综合污染指数均处于自然本底范围,且生态风险指数(ERI)值(0.84~1.45)也都属于生态低风险和无风险类别,但Cu、Zn、Pb和Cd的危害系数(HQi)大于1,属于潜在关注指标,应予以关注。

In order to study the pollution level of heavy metals in the surface seawater of the central fishing ports in the Yellow Sea and the Bohai Sea during the fishing off period and fishing period,sampling stations were set up in 11 central fishing ports along the coast of the Yellow and Bohai Sea in May and October 2020 to conduct water sample analysis.The content and pollution characteristics of 6 heavy metals including Zn,Pb,Cd,Hg and As were evaluated and analyzed,then,the main sources of heavy metals were explored and their ecological risks were assessed.The results showed that the range of concentrations of Cu,Zn,Pb,Cd,Hg and As during the fishing off season were 1.26~4.46μg/L,4.10~22.72μg/L,1.18~16.76μg/L,0.54~7.80μg/L,0.02~0.08μg/L and 0.02~0.86μg/L respectively.While which in the fishing season were 0.60~4.62μg/L,4.92~10.61μg/L,0.16~2.95μg/L,0.14~2.95μg/L,0.03~0.11μg/L and 0.16~1.37μg/L respectively.All the average concentrations of Cu,Zn,Pb,Cd,Hg and As of each fishing port were lower than the fourth categories of national seawater quality standards(GB 3097-1997).The concentrations of heavy metals in the surface seawater of the fishing port along the coastal of the Yellow Sea is slightly lower than that in the Bohai Sea.Compared with the East China Sea and the South China Sea,the concentration of Cu,Pb and Cd in the Yellow Sea and Bohai Sea is at a high level,the content of Zn and Hg is at a medium level,while the content of As is at a low level.It is found that Zn and As come from land discharging,while Cu come from both the land discharging and marine antifouling paint during the fishing off period and fishing period.However,Pb in surface seawater is related to the atmospheric deposition and fuel exhaust in the fishing pot zoon.Even though the comprehensive pollution index of heavy metals in the surface seawater of the central coastal fishing port is in the natural background range,and the ecological risk index(ERI)values(0.84~1.45)of heavy metals in the surface seawater of the coastal central fishing port are also in low risk or risk-free categories to the ecological,the Hazard Quotient(HQi)values of Cu,Zn,Pb and Cd are greater than 1,which were identified as potential heavy metals to be concerned.