渤海及北黄海2013-2017冬季拖网大型底栖动物群落结构及物种多样性

Community structure and species diversity of bottom trawling macrobenthos in the Bohai Sea and the North Yellow Sea in winter

关键词:  渤海  北黄海  拖网  大型底栖动物  经济种

Key words:  the Bohai Sea  the North Yellow Sea  bottom trawl  macrobenthos  economic species

摘要:

本文利用2013年、2014年、2016年和2017年共计4个冬季航次（12月）的大型底栖动物底拖网资料，对渤海及北黄海海域大型底栖动物群落特征进行了研究。4个航次共采集到大型底栖动物182种，包括软体动物64种，甲壳动物40种，鱼类26种，多毛动物34种，棘皮动物12种，其他动物6种。其中以棘皮动物的优势种地位最显著，其次为小型甲壳动物。调查海域总平均丰度为3.69 ind./m2，总平均生物量为0.88 g/m2，其中均以棘皮动物占绝对优势。丰度和生物量在空间分布上存在差异，高值站位主要分布在渤海中部、渤海海峡以及北黄海海域。多样性指数的高值站位主要分布在渤海海峡和渤海中部海域。主要经济种（相对重要性指数Index of Relative Importance, IRI>10）以日本褐虾Crangon hakodatei和日本鼓虾Alpheus japonicus等小型甲壳动物为主。CLUSTER聚类分析和nMDS分析表明，调查海域大型底栖动物群落差异性较大，大致可分为4个以不同优势种为代表的地理动物区系，即辽东湾，渤海中南部（莱州湾，渤海湾和渤海中部），渤海海峡和北黄海。丰度/生物量曲线分析表明，冬季渤海及北黄海海域底栖动物群落已经受到中等及以上程度的扰动。与历史资料对比发现，渤海及北黄海大型底栖动物整体呈现小型化和低值化的趋势。

Abstract:

Four surveys were carried out by bottom trawling in winter (December) of 2013, 2014, 2016 and 2017 to analyze the macrobenthic community in the Bohai Sea and the Northern Yellow Sea. A total of 182 species were identified, including 64 species of Mullusca, 40 of Crustacea, 26 of Fishes, 34 of Polychaetea, 12 of Echinodermata and 6 of other groups. The dominant species were mainly composed of echinoderms species, followed by small crustaceans species. The total average abundance and biomass were 3.69 ind./m2 and 0.88 g/m2, respectively, of which, the echinoderms accounted for the highest abundance and biomass. The distribution of abundance and biomass presented with an spatial difference in the survey areas, with high value found in the central Bohai Sea, the Bohai Strait and the North Yellow Sea. The Bohai Strait and the central area of the Bohai Sea were also presented with the high value of the diversity indices. The economic species (Index of Relative Importance, IRI>10) are mainly composed of small crustaceans species, such as Crangon hakodatei and Alpheus japonicus. CLUSTER and nMDS analysis showed that the macrobenthic community in Bohai sea were roughly divided into 4 geographic fauna represented by different dominant species, namely, the Liaodong Bay, central and southern Bohai Sea (Laizhou Bay, Bohai Bay and central Bohai Sea), Bohai Strait and North Yellow Sea. The abundance/biomass curves showed that the macrobenthic communities in the Bohai Sea and the North Yellow Sea were suffered from an moderate to high level disturbance. Compared with historical data, the macrobenthic species in the Bohai Sea and the North Yellow Sea are becoming smaller in body size and lower in economic value.