2007年6月经由专项航次对黄海冷水团及邻近海域共48个站位（北黄海17个，南黄海31个1的小型底栖动物组成、丰度和生物量及沉积环境进行了研究。所调查站位的小型底栖动物平均丰度达（2195±1599）ind／10cm^2，平均生物量为（1843±1291）μg dwt／10cm^2，冷水团内的平均丰度较冷水团外站位低约25％，生物量低约18％。北黄海的小型底栖动物现存量是南黄海的2倍多，平均丰度分别为（3410±1578）ind／10cm^2和（1529±1121）ind／10cm^2，平均生物量分别为（2766±1344）μg dwt/10cm^2和（1336±901）μg dwt／10cm^2。在分选出的18个小型底栖动物类群中，线虫在丰度上平均达总量的87．9％，其他依次为桡足类（5．9％）、甲壳类幼体（2．9％）、多毛类（1.3％）和动吻类（1．2％）。而生物量上的贡献依次为线虫（42％）、多毛类（22％）、桡足类（13％）和甲壳类幼体（12％）等。在垂直分布上，79％的小型底栖动物分布在0—2cm沉积物表层，17％分布于2—5cm次表层，底层5—8cm仅占4％。统计分析显示，小型底栖动物丰度和生物量与沉积物叶绿素α含量呈极显著正相关，与水深、沉积物有机质含量、中值粒径呈显著或极显著负相关，而生物量与沉积物（粉砂＋粘土）含量呈显著负相关。研究表明，黄海沉积物中有机质含量总体上呈近岸低、中央冷水团高的特点，可能与夏季环状流形成的海水涡旋有关。本研究在北黄海所获小型底栖动物现存量系中国海域同类研究的最高值，黄海的小型底栖动物高现存量区域与传统的高生产力区域一致。研究还发现，自长江口向东北方向分布的小型底栖动物现存量较周边海区为高，该路径与长江冲淡水向黄海的扩展路线一致，这可能是由于长江淡水带来丰富的营养盐，提供了较充足的食物所致。%Composition, abundance, biomass and environmental parameters of meiofauna were investigated based on samples collected from 48 stations （including 17 and 31 stations in the northern and southern Yellow Sea, respectively） in the area dominated by Yellow Sea Cold Water Mass and its surrounding areas in the summer 2007. The mean abundance and biomass of meiofauna in the sampling stations were （2195 ± 1599） ind/10cm^2 and （1843 4- 1291） μg dwt/10cm^2, respectively. The mean abundance of meiofauna in the 29 stations in the area dominated by the cold water mass was -25% lower than that in the other 19 stations, and the biomass was -18% lower. The abundance and biomass in the north Yellow Sea were -2 times more than those in the south Yellow Sea, i.e., the abundance was （3410 ± 1578） ind./10cm^2 and （1529 ± 1121） ind./10cm^2, respectively, and the biomass was （2766 ± 1344） μg dwt/10cm^2 and （1336 ± 901） μg dwt/10cm^2, respectively. Among the 18 main meiofaunal groups that we examined, free-living nematodes were the most abundant and contributed 87.9% to the total meiofaunal abundance, which was followed by copepods （5.9%）, nauplii （2.9%）, polychaetes （1.3%） and kinorhynchs （1.2%）. Nematodes contributed to 42% of the total meiofaunal biomass in the Yellow Sea, followed by polychaetes （22%）, copepods （13%） and nauplii 02%）. Moreover, -79% of the total meiofauna lived in surficial sediments （0-2 cm）, 17% lived in 2-5 cm depth, while only 4% were found in 5-8 cm depth. The abundance and biomass of total meiofauna showed significant positive correlation with chlorophyll a concentrations, and significant negative correlation with water depth, sediment organic matter concentration, and median diameter of sediment grains. In addition, meiofaunal biomass showed significant negative correlation with the content of silt and clay in the sediments. These results suggested that sediment organic matter concentration in the nearshore area were lower than those in the central area of the Yellow Sea. This phenomenon was likely caused by the annular circulation in the Yellow Sea in summer. The standing crop of meiofauna in the northern Yellow Sea was the highest ever recorded for China＇s seas. This high standing crop is consistent with high productivity in the Yellow Sea. Furthermore, meiofaunal standing crop was higher along the river plume from estuary of the Changjiang（Yangtze） River, which brought abundant nutrients to this area.
展开▼
