摘要
河口三角洲是人类活动最为剧烈的区域,陆海作用复杂,生态环境脆弱。2021年6月以潮汕韩江三角洲河口群为研究区,开展了河-海交互区沉积环境和小型底栖动物群落综合研究。结果表明,研究区沉积物以黏土质粉砂为主,中值粒径为6.66~1301.34μm;盐度为15.91~35.11,具有典型的河-海交互区特征;有机碳(TOC)、叶绿素a(chl a)、脱镁叶绿酸含量(Phaeo)均呈现由陆向海减少趋势。重金属Cu和Zn、Phaeo、透明度和砂含量是造成沉积环境差异的主要因素。共鉴定出13个小型底栖动物主要类群,其中自由生活海洋线虫在丰度和生物量上均为最优势类群(90%和38%),桡足类和多毛类居次。小型底栖动物的平均丰度和生物量(干重)分别为(295±195)inds./10 cm^(2)和(277.8±202.8)μg/10 cm^(2),整体上从陆向海呈增加趋势,在不同河口断面间差异显著。盐度和河口也是控制小型底栖动物群落空间分布的主要因素,真盐区(盐度>30)的群落相似性较高。小型底栖动物丰度、生物量和物种数与Phaeo和重金属(Cu、Zn、Pb、Cd)呈负相关关系;解释小型底栖动物群落结构差异的最佳环境组合是盐度和重金属Cd含量。基于重金属、有机污染指数及海洋线虫与桡足类比值三种环境评价方法,其结果均显示污染较严重的区域位于河口入海口门处。研究结果可为海岸带资源保护、生态监测以及基于生态系统实施综合管理提供基础数据支撑。
Estuarine delta is the most intense area of human activities,with complicated land-sea interaction and highly fragile ecology.Field observation and sediment sampling were carried out in Hanjiang River estuaries off Chaoshan,Guangdong in June 2021,to analyze the sedimentary environments and meiofaunal community for the deep understanding of ecological condition.Results showed that sediment was mainly clay-silt with a mgs range of 6.66~1301.34μm.The salinity varied from 15.91 to 35.11,reflecting typical characteristics of the river-sea interaction zone.Organic carbon content(TOC),chlorophyll a(chl a)and phaeophorbide(Phaeo)showed a decreasing trend from land to sea.Heavy metal Cu and Zn,Phaeo,transparency,and sand contents were the main factors leading to the differences of sedimentary environments.Thirteen major groups of meiofauna were identified,among which free-living marine nematodes were dominant species in abundance and biomass,accounting for 90%and 38%,followed by copepods and polychaetes.The mean abundance and biomass(dry weight)of meiofauna were(295±195)inds./10 cm^(2) and(277.8±202.8)μg/10 cm^(2),respectively,and the spatial distribution showed an overall increasing trend from land to sea,with significant differences among different estuarine sections.Salinity and estuary were also important factors influencing the spatial distribution of the meiofauna community.The community similarity was high in the euhaline region(salinity>30).The abundance,biomass,and the number of meiofaunal taxon were negatively correlated with Phaeo and heavy metals(Cu,Zn,Pb,Cd);the combination of salinity and heavy metal Cd was the best explanation for the differences of meiofauna community.Environmental assessments of heavy metals,organic pollution index,and the ratio of marine nematodes to copepods generally agreed well,showing that the most polluted area was located in the river mouth.This study provided the basic data for deep insight of resource protection,ecological monitoring,and implement of ecosystem-based integrated management.
作者
俞越
王嫣贝
范魏丰
董建玮
王红兵
袁振威
耿乐
杜永芬
李玉凤
YU Yue;WANG Yan-Bei;FAN Wei-Feng;DONG Jian-Wei;WANG Hong-Bing;YUAN Zhen-Wei;GENG Le;DU Yong-Fen;LI Yu-Feng(College of Marine Science and Engineering,Nanjing Normal University,Nanjing 210046,China;Haikou Marine Survey Center,China Geological Survey,Haikou 571127,China)
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2024年第1期155-170,共16页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金项目,41576154号
中国地质调查局海岸带综合地质调查项目,DD20208013号
2023年环境热点问题前瞻性监测研究-典型海洋生态系统调查及综合评价方法研究项目。
关键词
潮汕河口区
沉积环境
小型底栖动物群落
生态评价
Chaoshan estuarine
sedimentary environment
meiofaunal community
ecological assessment
