辽东湾北部海域大型底栖动物研究:Ⅰ.种类组成与数量分布

于2007年7月下旬在辽东湾进行了29个站位的大型底栖动物调查,共发现大型底栖生物79种;其中包括多毛类18科24种,甲壳动物15科19种,软体动物13科24种,棘皮动物4科6种,其他类群5种.整个调查区内大型底栖动物的优势现象不明显,优势度指数大于1%的物种仅有5种,分别为光滑河篮蛤、日本倍棘蛇尾、日本浪漂水虱、纽虫和西格织纹螺.调查区内底栖动物种类数、栖息密度以及生物量的高值区与低值区呈斑块状互相嵌套.大型底柄动物的平均栖息密度为68.28 m-2,平均生物量为22.75 g/m2;其中软体动物的平均栖息密度为30.52 m-2,生物量为6.92 g/m2;多毛类的平均栖息密度为14.48m-2,生物量为4.15g/m2;甲壳类的平均栖息密度为12.76 m-2,生物量为1.86g/m2;棘皮动物平均栖息密度为6.38 m-2,生物量为8.64 g/m2.1959年渤海各分区大型底栖动物的平均牛物量为10.29～12.83 g/m2.与其相比,除莱州湾外,目前各分区的平均生物量(16.45～22.75 g/m2)均显著升高,变化幅度有所增大.

Studies on Macrobenthos in the Northern Waters of Liaodong Bay: I. Species Composition and Number Distribution

A total of 58 grabs were collected from 29 stations with a 0.1 m² bottom sampler in the northern waters of Liaodong Bay (a semi-enclosed estuary in Liaoning Province) in July 2007, in which species composition and number distribution of macrobenthos were investigated. There were 79 macrobenthic species identified in the research region, which included 24 species of Polychaeta, 19 species of Crustacea, 24 species of Mollusca, 6 species of Echinodermata, and 5 species belonging to other taxonomical groups. The dominant species in this region were relatively few and only 5 species whose dominance indices were higher than 1%.They were Potamocorbula laevis, Amphioplus japonicus, Cirolana japonensis, Nemertinea and Nassarius siquijorensis. There were patches with low and high species, and the inhabit density and biomass of macrobenthos were mutually nested. The average inhabit density of macrobenthos was 68.28 m^-2 and the averagebiomass was 22.75 g/m². The average inhabit densities of Mollusca, Polychaeta, Crustacea, and Echinodermata were 30.52, 14.48, 12.76, and 6.38 m^-2, respectively, and the biomasses were 6.92, 4.15, 1.86, and 8.64 g/m², respectively. Compared with previous results that the average biomass of macrobenthos in the Bohai Sea ranged from 10.29 g/m² to 12.83 g/m² in 1959, the average biomass of macrobenthosin present region significantly increased (16.45-22.75 g/m²), exceptfor Laizhou Bay.