杭州湾和三门湾拖网大型底栖动物群落组成和多样性研究

本研究根据2017年8月和2018年8月在东海北部杭州湾和三门湾大型底栖动物的拖网采集资料,对这两个海域的大型底栖动物群落结构和多样性进行了研究。杭州湾的10个站位和三门湾的6个站位共获得61种大型底栖动物,其中甲壳动物最多(22种),其次是鱼类(20种)、软体动物(14种)、棘皮动物(2种)、刺胞动物(2种),多毛类最少(1种)。杭州湾大型底栖动物优势种出现3种,三门湾出现8种,脊尾白虾Palaemoncarinicauda是两个海域唯一的共同优势种。相比2017年,杭州湾和三门湾在2018年鱼类的种类和数量都有明显的增长。根据大型底栖群落的多样性指数,杭州湾不同区域的生物多样性差异较大,而三门湾则较为平均。对杭州湾和三门湾大型底栖动物进行聚类分析和nMDS排序分析,结果表明,杭州湾不同站位大型底栖动物相似度低,Q8、Q9、Q10站位群落结构与三门湾的站位更为接近,三门湾的底栖群落在2017年和2018年存在较大差异。杭州湾和三门湾大型底栖动物群落的变化可能与环境因子、人类活动、厄尔尼诺事件等的变化相关。

COMMUNITY COMPOSITION AND DIVERSITY OF MACROBENTHOS TRAWLED IN HANGZHOU BAY AND SANMEN BAY

Based on the annual trawling macrobenthos from Hangzhou Bay and Sanmen Bay in the north of the East China Sea during August 2017 to August 2018, the community structure and diversity of macrobenthos in the two bays were studied. A total of 61 species of macrobenthos were collected from 10 stations of Hangzhou Bay and 6 stations of Sanmen Bay, among which the crustaceans were the most abundant macrobenthic taxa (22 species), followed by fish (20 species), molluscs (14 species), echinoderms (2 species), cnidarians (2 species), and polychaete (1 species). There were three dominant macrobenthic species in Hangzhou Bay and eight dominant species in Sanmen Bay. Palaemon carinicauda was the only common dominant species in the bays. Compared with those of 2017, the species and quantity of fish in Hangzhou Bay and Sanmen Bay increased significantly in 2018. The diversity index of different stations showed that the biodiversity in different areas of Hangzhou Bay was significantly different, while Sanmen Bay was relatively even. Clustering analysis and nMDS ordination for the macrobenthos presented that the community structure of macrobenthos in different stations of Hangzhou Bay was significantly different. The community structures of macrobenthos of three stations near the southern border of the Hangzhou Bay and close to the Sanmen Bay were similar to those from Sanmen Bay, and the benthic community of Sanmen Bay was quite different in 2017 and 2018. Therefore, we believed that the variations of benthic community in Hangzhou Bay and Sanmen Bay was related to the changes of environmental factors, human activities, and El Nino events.