基于重金属与底栖生物群落结构耦合关系的近海沉积物环境质量综合评价体系构建

发布时间：2018-05-13 08:49

本文选题：重金属 + 底栖生物　；参考：《中国科学院研究生院（海洋研究所）》2014年博士论文

【摘要】：海洋沉积物作为陆源物质的主要接收地，在海洋物质循环中占据极为重要的地位，海洋沉积物的环境质量与水体及生物群落息息相关，对海洋生态系统运转产生影响，所以，科学客观地表征海洋沉积物的环境质量至关重要本学位论文在揭示渤海典型河口和海湾沉积物中重金属与底栖生物群落结构耦合特征的基础上，系统开展了沉积物指标筛选评价阈值和评价方法的解析，构建了海洋沉积物环境质量新型综合评价体系获得了如下的主要结论： 1．渤海沉积物中重金属含量水平与底栖生物群落具有对应关系，底栖生物群落结构受重金属的影响具有显著的区域性差异，渤海湾底栖生物群落分布显著受As影响，为As提供了群落水平上的关键生态相关性证据；莱州湾底栖生物在Zn含量较高的站位数量较多，显示在低含量水平下Zn对生物生长的促进作用；锦州湾底栖生物群落受Cu Pb Zn和Cd等重金属严重污染影响，结构和功能受到严重损害，难以在该海域生存渤海湾沉积物金属含量明显反映了沿岸人为活动的影响，南部远岸区站位底栖生物群落结构显著受到重金属影响，多样性较低，软体动物占绝对优势地位典则对应分析(Canonical correspondence analysis，简称CCA)分析结果表明Zn对近岸海域底栖生物的分布影响较大，As和Hg对南部海域的底栖生物的影响也较为显著，其中As与底栖生物群落分布显著相关(F=1.988，P=0.0260)，这为As提供了群落水平上的关键生态相关性证据莱州湾沉积物中重金属具有人为源和自然源，其中河流径流为主要输入途径，相关性分析显示Cu和As可能具有相同来源重金属(Metals-PC1)底栖生物群落结构(DIM1)无显著统计相关性，表明相较于重金属，由河流输入引起的物理栖息环境变化是影响底栖群落结构更重要的因素统计分析还显示Zn与物种总丰度具有显著相关性(rs=0.646, P0.01)，这表明底栖生物在Zn含量较高的站位数量较多黄河口表层沉积物重金属含量水平整体较低的情况下，，统计分析表明生物量大的底栖生物(软体动物)在重金属含量较高的站位数量较多锦州湾生态系统结构和功能严重退化，其沉积物中的Cu Pb Zn和Cd等长期处于高风险水平，其中尤以湾内靠近五里河排污口和葫芦岛锌厂的站位显著，对海洋生态生态系统造成了严重的影响底栖生物调查结果显示仅在零星站位发现极个别的底栖生物，表明在重金属严重污染的影响下，底栖生物仍难以在该海域生存，显示锦州湾沉积物中重金属污染严重 2．基于沉积物化学-底栖生物群落结构耦合关系，以底栖生物群落结构变化与否作为沉积物环境质量好坏标准的沉积物环境质量综合评价结果显示，渤海(除锦州湾外)沉积物环境质量并未如先前人们所熟知的那么恶劣在渤海，渤海湾中部渤海中部以及莱州湾西部的沉积物环境质量普遍较好，而沉积物环境质量较差的站位仅分布于渤海湾南部黄河河口附近小清河口及莱州湾北部，其中渤海湾南部海域沉积物质量较差与高含量Hg的影响有关，莱州湾中北部沉积物质量较差与沉积物中高含量的Cu和As的影响有关，而黄河河口附近和莱州湾部分海域沉积物质量较差主要原因可能与以河流输入为主导的物理胁迫因子有关从这些海域的沉积物综合评价结果整体评判，沉积物质量较差的区域并不多，且从历史数据对分析可知，这些海域沉积物物中重金属水平均有显著下降的趋势，因此，渤海(除锦州湾外)沉积物环境质量并没有像先前人们所熟知的那么恶劣 3．基于沉积物化学-底栖生物群落结构耦合关系，构建了海洋沉积物环境质量新型综合评价体系，包括筛选出5个组别共18种传统化学致污物和10种备选的新兴致污物的化学指标体系，构建了评价阈值，制定了综合评价指数(IQI) 系统分析了化学评价指标的生态相关性，筛选出了5个组别共18种传统化学致污物和10种备选的新兴致污物的新型指标体系；基于柱状沉积物中重金属百年前含量，计算并确定了渤海不同区域的背景值；构建了以9个TECs8个PECs为基础，包含我国近海沉积物区域特征的一致性沉积物质量参考值；以渤海沉积物环境质量综合评价结果为依据，基于证据权重思想，构建了综合评价指数(IQI)
[Abstract]:As the main source of marine sediments , marine sediments occupy a very important position in the circulation of marine matter . The environmental quality of marine sediments is closely related to the water and biological communities . Therefore , it is very important to scientifically and objectively characterize the structural coupling characteristics of heavy metals and benthos in the typical estuary and bay sediments of the Bohai Sea .

1 . The content of heavy metals in the sediments of Bohai Sea has a corresponding relationship with benthos community , and the structure of benthos is influenced by heavy metals . The distribution of benthos community in Bohai Bay is significantly affected by As , which provides the key ecological correlation evidence for As .
The level of Zn in benthos in Laizhou Bay is higher , which shows that Zn can promote the growth of organisms at low levels .
It is difficult to survive in the sea area due to the serious pollution of heavy metals such as Cu , Pb , Zn , Cd and other heavy metals in the benthos community in Jinzhouwan Bay .

The metal contents of sediment in the Bohai Bay reflect the influence of anthropogenic activities along the coast . The structure of the benthos community in the southern coastal area is significantly affected by heavy metals , the diversity is low , and the mollusks account for the dominant position of the benthos in the coastal waters . As a result , the distribution of As and Hg is significantly related to the benthos in the southern sea area ( F = 1.988 , P = 0.0260 ) , which provides the key ecological correlation evidence for As in the community level .

Heavy metals in the sediments of Laizhou Bay have artificial sources and natural sources , in which river runoff is the main input route , and the correlation analysis shows that Cu and As may have the same source heavy metal ( Metals - PC1 ) benthic community structure ( DIM1 ) has no significant statistical correlation , which indicates that the change of physical habitat environment caused by river input is a more important factor affecting the structure of benthic communities ( rs = 0.646 , P0.01 ) . This indicates that the benthic organism ( mollusk ) with higher Zn content has a significant correlation with the total abundance of heavy metals ( rs = 0.646 , P0.01 ) .

The ecological system structure and function of Jinzhou Bay are seriously degraded , Cu Pb Zn and Cd in sediments are at high risk level for a long time .

2 . Based on the relationship of sediment chemistry - benthos community structure coupling , the environmental quality of sediments in the Bohai Sea ( except Jinzhouwan ) is not as bad as that of the previous people .

In the Bohai Sea , the sediment quality is generally better in the middle of the Bohai Sea in the middle of the Bohai Sea and in the west of the Laizhou Bay . The lower sediment quality in the southern Yellow River is related to the high content of Cu and As in the south of the Bohai Bay . The main reason for the poor sediment quality in the south of the Yellow River is not much related to the high content of Cu and As in the sediments , and it can be seen from the historical data that the environmental quality of the sediments in the Bohai Sea ( except the Jinzhouwan ) is not as bad as that of the previous people .

3 . Based on the relationship of sediment chemistry - benthos community structure coupling , a new comprehensive evaluation system for marine sediment environment quality was constructed .

This paper systematically analyzes the ecological relevance of chemical evaluation index , and filters out a new index system of 18 kinds of traditional chemical pollutants and 10 alternative newly developed soils .
The background values of different regions in the Bohai Sea are calculated and determined based on the pre - century contents of heavy metals in columnar sediments ;
Based on 9 TECs 8 PECs , the consistency sediment quality reference value of the regional characteristics of offshore sediment in China is constructed .
Based on the results of comprehensive evaluation of environmental quality in Bohai Sea sediment , based on the evidence weight thought , a comprehensive evaluation index ( IQI ) was constructed .

【学位授予单位】：中国科学院研究生院（海洋研究所）
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P736.21

【参考文献】