摘要
《北斗号》调查船分别于 2 0 0 0年 10月和 2 0 0 1年 4月在 2 6°N至 36°N,12 0°E至 12 6°30′E东、黄海陆架浅水区调查中进行了小型底栖生物的取样。研究表明 ,两个航次 (秋季、春季 )小型底栖生物的平均丰度分别为 6 5 4 .2 5± 4 4 1.72 ind/10 cm2 和342 .0 0± 2 5 2 .0 0 ind/10 cm- 2 ,平均生物量分别为 80 7.0 6± 5 17.89μg dwt/10 cm2 和 2 85 .2 5± 173.72μg dwt/10 cm2 ;平均生产量分别为 72 6 3.5 8± 4 6 6 4 .18μg dwt/(10 cm2· a)和 2 5 6 7.2 8± 15 6 3.5 0 μg dwt/(10 m2· a)。两个航次小型生物的平面分布类似 ,即高密度和高生物量区分布在水深等深浅 5 0 m左右的站位上 ,特别是在长江口以南的浙江沿海。共鉴定出 14个小型生物类群 ,按丰度自由生活海洋线虫是最优势的类群 ,秋、春季两个航次的优势度分别为 87.2 %和 91.2 %。其他优势类群依次为底栖桡足类、多毛类和动吻类 ;按生物量优势依次为多毛类 38.1%～ 5 4 .0 % ,线虫 2 8.3%～ 38.1%和桡足类 9.0 %～ 9.4 %。垂直分布的研究表明 ,91%的小型生物分布在 0～ 5 cm的表层内 ,线虫和桡足类分布在 0～ 2 cm的比例分别为 6 3%和 86 %。相关分析表明 ,小型底栖生物的数量分布与粘土含量 (% )、粉砂粘土含量 (% )
Meiobenthos abundance, biomass and its relation to the sedimentary environment in the East China Sea and the Yellow Sea were investigated based on samples collected by R/V Beido in autumn (October, 2000) and spring (April 2001). The dominant sediment type was very poor sorted silt-clay, with median diameter (MDφ) from 5.64 to 8.26, and silt-clay content from 85.7% to 99.8%, this was found in the bottom of the cold water mass in central Yellow Sea, off the Yentze River estuary and in the southern part of Zhejiang coastal waters. The second dominant sediment type was fine sand with median diameter (MDφ) from 2.57 to 3.34, and sand content from 64% to 94%, which was found mainly off the Yantze estuary and in the southern area where water depth is from 50m to 100m. The average concentrations in the top 5cm of sediment of Chl-a and Pha-a were 0.79±0.78 mg/kg sand and 2.32±2.13 mg/kg sand respectively in spring. Corresponding values for Chl-a and Pha-a were 44% lower in autumn. Total average abundance of meiobenthos was 654.25±441.72 ind/10cm^2 and 342±252 ind/10cm^(2) in autumn and spring respectively, with corresponding biomass of 807.06±517.89 μg. dwt/10cm^2 and 285.25±173.72 μg. dwt/10cm^2 in the two seasons. There were similar patterns of spatial distribution for abundance and biomass in both seasons, that is, high values occurred along the isobath of 50m water depth, off the Zhejiang coastal waters in particular. Correlation analysis showed that there was significant correlation of abundance with clay, silt-clay content (%) and median diameter (MDφ), and highly significant correlation with Chl-a and Pha-a concentration. A total of fourteen meiobenthos groups was identified. The most numerous taxonomic groups were nematodes, with relative dominance 87.2% in autumn and 91.2% in spring. The following groups were also important: benthic harpacticoids copepods, polychaetes and kinorhyncha. In terms of biomass, dominant groups were polychaetes (38.1%～54.0%), nematodes (28.3%～38.1%) and copepods (9.0%～9.4%). Analysis of vertical distribution indicated that 91% of the meiobenthos were in the top 0～5 cm of sediment. Analysis of species composition of free living marine nematodes from five selected typical stations showed that the most dominant species differed between each station. As expected, the highest biodiversity was found at coastal station B4 (H′=3.79) and at station E4 (H′>3.94), the transitional area of the Yellow Sea with the East China Sea. Lowest biodiversity was observed at the cool water mass station C5 (H′=2.80) in the central Yellow Sea, because of the relative stability and homogeneity of the sedimentary environment. There were higher H′Values at station F2 and H2 North and South of the Yantze River estuary. The patterns in the cluster dendrogram, together with the biodiversity analysis showed that the five selected stations came from totally different habitats and represent distinct communities. Comparison of biomass and production of meiobenthos with macrobenthos indicated that although the meiobenthic biomass is low, its production is almost equal to or even higher than that of macrobenthos because of the fast growing and much shorter life cycles for meiobenthos. More information is needed to identify the importance of these small animals in the energy flow of the benthic ecosystem in the East China Sea and the Yellow Sea.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第5期997-1005,共9页
Acta Ecologica Sinica
基金
国家重点基础研究资助项目 ( G19990 43 7)
国家自然科学基金资助项目 ( 4 0 1760 3 3 )~~
关键词
小型底栖生物
自由生活海洋线虫
丰度
生物量
黄海和东海
meiobenthos
freeliving marine nematodes
abundance
biomass
East China Sea and Yellow Sea
