| 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的综合研究。结果表明，河口沉积物类型以黏土质粉砂为主，中值粒径范围为 6.66~1301.34 μm；盐度为15.91~35.11，具有典型的河-海交互区特征；有机碳含量(TOC)、叶绿素a (Chl-a)、脱镁叶绿酸含量(Phaeo) 均呈现由陆向海减少的趋势。重金属Cu和Zn含量、Phaeo、透明度和砂含量是造成沉积环境产生差异的主要原因。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平均生物量分别为(295±195) inds./10 cm2和 (277.8±202.8) μg·dwt/10 cm2，整体上从陆到海呈降低趋势，在不同河口断面间差异显著。海洋环境区的群落相似性较高，盐度和河口断面是影响小型底栖动物群落分布的重要因素。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。解释小型底栖动物群落结构差异的环境最佳组合是盐度和重金属Cd含量。基于重金属、有机碳及海洋线虫与桡足类比值(N/C) 显示污染较严重的站位处于河口入海口门处。 |
| 关键词: 潮汕河口区 沉积环境 小型底栖动物 群落结构 |
| DOI：10.11693/hyhz20230800160 |
| 分类号: |
| 基金项目: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。 |
附件 |
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| RESEARCH ON THE SEDIMENT ENVIRONMENT AND MEIOFAUNA COMMUNITY STRUCTURE IN RIVER - OCEAN INTERACTION AREA OFF CHAOSHAN COAST |
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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
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1.School of Marine Science and Engineering, Nanjing Normal University, Nanjing, China;2.Haikou Marine Survey Center, China Geological Survey, Haikou, China
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| Abstract: |
| Estuarine delta is the most intense area of human activities, with complicated interaction of the rivers and oceans and fragile ecological environment. In this study, field observation and sediment samplings were carried out in Han River Delta estuary off the Chaoshan coast, in June 2021, to learn the sedimentary environment, distribution and community characteristic of meiofauna for a deep outsight of ecological condition. The results showed that sediment type in the estuary was mainly clay -silt with a median grain size range of 6.66-1301.34 μm. The salinity varied from 15.91 to 35.11, with typical characteristics of the river-ocean interaction zone. The chlorophyll-a (Chl-a), phaeophorbide (Phaeo), and organic carbon content (TOC) showed a trend of decreasing from land to sea. Heavy metal Cu and Zn contents, Phaeo, transparency and sand contents were the main reasons for the differences in station environments. A total of 13 major groups of meiofauna were identified, among which free-living marine nematodes were the most dominant species, accounting for 90% of the total abundance, followed by copepods and polychaetes. The mean abundance and biomass of meiofauna were (295±195) inds./10 cm2 and (277.8±202.8) μg·dwt /10 cm2, respectively, and the spatial distribution showed an overall decreasing trend from land to sea, with significant differences among different estuarine sections(p < 0.05). The community similarity was high in the marine environment region, and salinity and section location were important factors influencing the distribution of the meiofauna community. The abundance, biomass and species’ number of meiofauna were negatively correlated with Phaeo and heavy metals (Cu, Zn, Pb, Cd); the combination of environmental factors of salinity and heavy metal Cd could best explain the community structure of meiofauna in the river-sea interaction zone of Chaoshan coastal zone. Based on heavy metals, organic carbon and the ratio of marine nematodes to copepods(N/C), the most polluted stations were located at the estuarine gate. |
| Key words: Chaoshan coast estuaries sedimentary environment meiofauna community structure |