广西北部湾近岸养殖区表层沉积物和养殖生物体重金属污染状况及生态风险评价

Heavy Metal Pollution Status and Ecological Risk Assessment of Surface Sediments and Mariculture Organisms in the Coastal Mariculture Areas of Beibu Gulf,Guangxi

关键词:  重金属  表层沉积物  养殖生物体  生态风险评价  养殖区  北部湾

Key words:  heavy metals  surface sediments  cultured organisms  ecological risk assessment  mariculture area  Beibu Gulf

摘要:

为阐明广西北部湾近岸养殖区重金属污染状况及潜在来源，根据2013-2016年广西北部湾4个主要海水养殖区的海洋环境监测调查数据，分别应用单因子指数法、综合污染指数法、潜在生态风险指数法和地积累指数法评价研究区表层沉积物的重金属污染程度，应用单因子指数法评价养殖生物体的重金属污染程度。结果表明：4个养殖区沉积物中大部分重金属含量超过国家海洋沉积物质量一类标准；4个海水养殖区表层沉积物重金属潜在生态风险从高到低为防城港红沙大蚝养殖区＞北海廉州湾海水增养殖区＞钦州茅尾海大蚝养殖区＞防城港珍珠湾珍珠养殖区；重金属污染因子中，Hg的潜在风险程度最高。从地积累指数和级别评价结果可知，广西4个养殖区表层沉积物5种重金属的污染程度为Cu＞Hg＞As＞Pb＞Cd，其中Cu主要受到人类活动(如渔船活动、养殖活动)影响。养殖生物体中重金属污染程度最严重的是钦州茅尾海大蚝养殖区，其他3个养殖区的养殖生物也不同程度地受到不同重金属的污染。因此，广西北部湾养殖区重金属污染状况不容忽视，尤其是Hg和Cu污染，未来仍需警惕。

Abstract:

In order to clarify the pollution status and potential sources of heavy metals in the coastal mariculture area of Beibu Gulf,Guangxi,based on the data of marine environmental monitoring survey data of 4 main marine mariculture areas in Beibu Gulf of Guangxi from 2013 to 2016,the single factor index method,intergraded pollution index method,potential ecological risk index method and geo-accumulation index method were used to evaluate the pollution degree of heavy metals in surface sediments of the study area,and the single factor index method was used to evaluate the pollution degree of heavy metals in mariculture organisms.The results showed that most of the heavy metals in the sediments of the 4 mariculture areas exceeded the national marine sediment quality standard.The potential ecological risks of heavy metals in the surface sediments of the 4 main mariculture areas from high to low was Oyster mariculture area in Hongsha,Fangchenggang>mariculture area in Lianzhou Bay,Beihai>Oyster mariculture area in Maowei Sea,Qinzhou>Pearl mariculture area in Pearl Bay,Fangchenggang.Among heavy metal pollution factors,Hg had the highest potential risk.According to the results of geo-accumulation index and pollution level,the pollution levels of 5 heavy metals in surface sediments from 4 mariculture areas in Guangxi were in the order of Cu>Hg>As>Pb>Cd,in which Cu was mainly affected by human activities (such as fishing boats activities and mariculture activities).The most serious pollution of heavy metals in mariculture organisms was the oyster culture area of Maowei Sea in Qinzhou,and the mariculture organisms in the other three culture areas were also polluted by different heavy metals to varying degrees.Therefore,the heavy metal pollution in mariculture areas of Beibu Gulf of Guangxi cannot be ignored,particularly Hg and Cu,which still need to be vigilant in the future.