舟山岛北部海域虾蟹类物种多样性的季节变化研究

Seasonal Variation of Shrimp and Crab Biodiversity in the Northern Waters of Zhoushan Island

根据2020年10月(秋季)、2021年1月(冬季)、4月(春季)、6月(夏季)在舟山岛北部海域开展渔业资源底拖网调查所获得的虾蟹类资料,利用相对重要性指数(IRI)、生物多样性指数、聚类分析、多元统计分析等方法,对调查海域的虾蟹类群落结构特征及其生物多样性进行了研究分析。结果表明:调查海域四季采集的渔获物共鉴定出虾蟹类25种,隶属于14科20属,其中虾类16种,蟹类9种。以冬季最多(17种),秋季最少(12种);优势种组成一年四季变化较小,主要有安氏白虾、细螯虾、三疣梭子蟹、中国毛虾共4种。生物多样性指数(H′)平面分布上存在极显著差异(P<0.01),除冬季外,其它3个季节的生物多样性指数(H′)高值区主要集中在调查海域的中部。单因素方差分析显示,水深<20 m不同站位之间生物多样性(H′)差异呈显著性(P<0.05),水深在20~40 m差异呈不显著性(P>0.05),水深>40 m差异呈极显著性(P<0.01),说明水深是影响该海域虾蟹类生物多样性(H′)的重要因素。聚类分析和排序结果显示,调查海域的虾蟹类群落结构可划分为2~3个组群,生态类型以广温低盐型和广温广盐型为主。研究结果可为舟山渔场渔业资源可持续利用及各类涉海工程项目建设对生态环境影响评价提供参考依据。

According to the shrimp and crab survey using bottom trawl in the northern waters of Zhoushan Island during October 2020(autumn),January 2021(winter),April(spring),and June(summer),we investigated the characteristics and biodiversity of shrimp and crab communities in the surveyed sea area by using methods such as Importantce Relative Index(IRI),Biodiversity Index,cluster analysis,and multivariate statistical approaches.The results showed that 25 species of shrimps and crabs were identified in the four seasons of the surveyed area,belonging to 14 families and 20 genera,including 16 species of shrimps and 9 species of crabs.The numbers of species are high in winter(17 species)and are less in autumn(12 species).The communities of dominant species showed non-significant seasonal variations.The four main species in the whole year are Exopalaemon annandalei,Leptochela gracilis,Portunus trituberculatus and Acetes chinensis.The spatial distribution of biodiversity index(H′)showed significant differences(P<0.01).The high biodiversity index(H′)in the whole years season except winter were mainly concentrated in the central part of the surveyed sea area.One-way analysis of variance(ANOVA)showed that the difference in biodiversity(H′)was significant in water depths<20 m,non-significant in water depths between 20-40 m,and extremely significant in water depths>40 m.The results of cluster analysis showed that the community structure of shrimp and crabscould be divided into 2-3 ecological groups,groups living in wide temperature and low salinity environment,groups living in the wide temperature and wide salinity environment.The results provide a reference basis for the sustainable utilization of fishery resources in the Archipelago Seas and evaluation on the effect of marine projects.