【作者】 华尔；

【导师】 张志南；

【作者基本信息】 中国海洋大学 ， 生态学， 2006， 博士

【摘要】 本文利用2003年6月和2004年9月在长江口外及其邻近海域36个站位所采集的未受扰动的沉积物样品,对长江口及其邻近海域小型底栖生物的环境,小型底栖生物的数量,自由生活海洋线虫的群落结构,多样性和分类学进行了研究。本文系对长江口外海域小型底栖生物群落结构及多样性的首次系统研究。同时还就线虫群落对台风扰动和缺氧(Hypoxia)/无氧(Anoxia)生境的适应及耐受过程进行了初探,以期解释台风扰动和缺氧/无氧生境线虫群落结构的变化。研究结果如下:研究海域沉积物以粘土质粉砂(YT)和粉砂质粘土(TY)为主。沉积物粒度参数受长江径流的影响较为显著;在不同航次,因长江径流量的不同沉积物粒度参数发生了一定的变化。沉积物粒级和组分又影响着该海域沉积物有机质和叶绿素a的含量和分布。在2003年6月航次,沉积物叶绿素a(Chl-a)、脱镁叶绿酸(Pha-a)和有机质含量高,分别为2.469±0.565mg/Kg,5.656±0.899mg/Kg和8.09%±2.00%。2004年9月航次,沉积物Chl-a和Pha-a含量也较高,与2003年航次无显著的差异(1.784±0.525mg/Kg和5.689±1.761mg/Kg);但有机质含量明显降低,约为2003年航次的1/10(0.92%±0.41%)。Pearson’s相关分析表明,沉积物Chl-a、Pha-a和有机质含量等不仅与沉积物粒度参数相关,也与水深,底层水温,底层盐度等具有不同程度的相关性(P<0.01或0.05)。因此,影响长江口及其邻近海域沉积物中Chl-a、Pha-a和有机质含量等小型底栖生物生活必需条件的因子有水深,底层水温,底层盐度,粉砂粘土含量和中值粒径等,但主要因子是沉积物粒度。在研究海域,共鉴定出自由生活线虫(Nematoda),底栖桡足类(Copepoda),多毛类(Polychaeta),介形类(Ostracoda),双壳类(Bivalvia),腹足类(Gastropoda),腹毛类(Gastrotricha),动吻类(Kinorhyncha),涡虫类(Turbellaria),海螨类(Halacaroidea),寡毛类(Oligochaeta),端足类(Amphipoda),异足类(Tanaidacea),等足类(Isopoda),海蜘蛛(Pycnogonida),涟虫类(Cumacea),更多还原

【Abstract】 Quantitative studies on the community structure and biodiversity of meiofauna in the Changjiang (Yangtze River) estuary and its adjacent waters are based on the samples collected from 36 stations during the cruises in Jun. 2003 and Sep. 2004. This paper deals with meiofauna abundance and biomass, community structure and biodiversity of free living marine nematodes, and benthic habitat of meiofauna in the Changjiang (Yangtze River) estuary and its adjacent waters. The comparative studies on changes of benthic and biotic factors between the 200306 and 200409 cruises has been made. This is the first time to discussing meiofauna community structure systematically in the Changjiang (Yangtze River) estuary and its adjacent waters. It also conducts some studies on nematode community responses to natural disturbance and community changes in low oxygen habitats.The dominant sediment types of the sampling stations are silt-clay (TY) and clay-silt (YT). The sedimentary environments of the studied stations vary with the seasonal changes of Changjiang (Yangtze) river runoff. In June, the average content of chlorophyll a(Chl-a), phaeophorbide a (Pha-a) and organic matter are high, which are 2.469±0.565mg/Kg, 5.656±0.899mg/Kg and 8.09%±2.00% respectively. Compared with that, Chl-a and Pha-a hold little differences in September, 2004, averaging at 1.784±0.525mg/Kg and 5.689±1.761mg/Kg respectively. However, the content of sediment organic matter reduces drastically in September, and accounts for only 1/10 (0.92%±0.41%) of that in June. Pearson’s correlated analysis among environmental factors shows that Chl-a, Pha-a and organic matter content are correlated with granulate parameters, water depth, bottom-water temperature and salinity (p<0.01 or 0.05). They are influencing the quantities and distributions of Chl-a, Pha-a and organic matter in the studied area. Among the influencing factors,更多还原