浙江檀头山岛周围海域夏、秋季大型底栖动物群落结构特征

摘要

为揭示现阶段浙江檀头山岛周围海域大型底栖动物群落现状,于2013年7月、2013年11月对该海域进行了2航次的大型底栖动物生态调查,20个采样站位共获得大型底栖动物55种,其中甲壳动物最多,有18种(占32.73％),其次是底栖鱼类(17种,占30.91％)、软体动物(16种,占29.09％),腔肠动物3种(5.45％),环节动物最少,只有1种(1.82％).2航次共鉴定大型底栖动物优势种14种,其中葛氏长臂虾Palaemon gravieri、细巧仿对虾Parapenaeopsis tenella为2航次共有优势种,其余均为单一航次优势种,夏、秋季间种类更替率较高,为51.85％.平均生物量、丰度,夏季航次均分别高于秋季航次,方差分析表明生物量、丰度两航次间均存在显著差异(P＜0.05),远近岸间均不存在显著差异(P＞0.05).对檀头山岛周围海域夏季和秋季大型底栖动物群落结构进行聚类分析和nMDS排序分析,结果表明,夏季、秋季20个站位均可划分成2个主要聚类组,对各聚类组内平均相似度贡献较大的物种主要是广温、广盐性的甲壳类动物,如东方口虾蛄Oratosquilla oratoria、中国毛虾Acetes chinensis、细螯虾Leptochela gracilis、葛氏长臂虾Palaemon gravieri、中华管鞭虾Solenocera crassicornis、三疣梭子蟹Portunus trituberculatus等.ABC曲线和多样性指数分析表明,檀头山岛周围海域大型底栖动物群落在秋季受到重度扰动,夏季未受到扰动.粒径分析结果显示檀头山岛周围海域沉积物主要是由较细颗粒的黏土和粉砂组成.CCA分析结果表明温度、盐度、水深、溶解氧是对大型底栖动物影响程度较大的环境因子.%This study reveals the status of macrobenthic fauna in the surrounding area of Tantoushan Island in Zhejiang Province.In July 2013 and November 2013,the macrobenthos fauna survey of 20 sampling stations was carried out.Fifty-five macrobenthos species were sampled with Agassiz trawl and identified,including,in number of species,18 crustacean (32.73％),17 benthic flatfish (30.91％),16 mollusks (29.09％),3 coelenterates (5.45％),and 1 annelid (1.82％).Fourteen dominant species of macrobenthos were recognized in the 2 seasons,among which Palaemon gravieri and Parapenaeopsis tenella were dominant in both seasons,while the rest were dominant in one season only.The species replacement rate was high for 51.85％ between summer and autumn.The average biomass and abundance were greater in summer than in autumn.Variance analysis showed that biomass and abundance was significantly different in season (P＜0.05),but in space inshore and offshore (P＞0.05).Clustering analysis and nMDS ordination for the macrobenthos community presented two major clusters made of mainly euryhaline and eurythermal species,such as Oratosquilla oratoria,Acetes chinensis,Leptochela gracilis,Palaemon gravieri,Solenocera crassicornis,Portunus trituberculatus etc.ABC curve and diversity index analysis found that the macrobenthos communities were extensively disturbed in the autumn but slightly in the summer.Particle size analysis displayed that the sediment of the study area was mainly fine-grained clay and silty sand.Finally,canonical correlation analysis revealed that temperature,salinity,water depth,and dissolved oxygen were the main environmental factors affecting the macrobenthos communities.