广西北海海域潮下带底栖贝类物种组成及时空分布

为了解北海海域潮下带底栖贝类的分布特征，给底栖贝类的保护、开发和利用提供参考，本研究采用潜水员水肺潜水、海底样方定量采集方法，对北海市廉州湾、侨港、白龙和营盘等4个海区潮下带底栖贝类的种类、数量及时空分布特征进行调查。结果表明，北海海域4个海区潮下带底栖贝类有2纲9目31科60属102种，其中腹足纲(Gastropoda)13科14属17种，双壳纲(Bivalvia)18科46属85种。春季有55种底栖贝类，秋季有76种，春季和秋季共有的种类有29种。秋季的廉州湾海区底栖贝类种类数和个体数都是最少的，秋季的侨港海区出现的底栖贝类种类数最多，个体数最多的出现在春季的营盘海区。平均栖息密度最高的是春季的营盘海区，达到27.35个/m²，平均栖息密度最低的是春季的廉州湾海区，只有1.00个/m²。春、秋两季4个海区的优势种差异较大。多项生物多样性指数结果表明,春季的营盘海区底栖贝类生物多样性差，底栖贝类群落结构处于重度受干扰状态；秋季的4个海区底栖贝类生物多样性较丰富，秋季的底栖贝类群落结构总体处于比较健康的状态。

Species Composition and Spatial-Temporal Distribution of Benthic Shellfish in Subtidal Zone of Beihai in Guangxi

In order to understand the distribution characteristics of benthic shellfish in the subtidal zone of Beihai,and provide reference data for the protection,development and utilization of benthic shellfish,the species,quantity and spatiotemporal distribution of benthic shellfish in subtidal zone of 4 sea areas(Lianzhou Bay,Qiaogang,Bailong and Yingpan) in Beihai City were investigated by diver scuba diving and quantitative collection of seabed samples.The results showed that there were 2 classes,9 orders,31 families,60 genera and 102 species of subtidal benthic shellfish in 4 sea areas of Beihai,including 17 species of 13 families,14 genera belonged to Gastropoda and 85 species of 46 genera of 18 families belonged to bivalves.There are 55 species in spring,76 species in autumn,and 29 species shared by spring and autumn.The number of species and individuals in the Lianzhou Bay sea area in autumn is the least,the number of species in the Qiaogang sea area in autumn is the most.The largest number of individuals appeared in Yingpan sea area in spring.The highest average habitat density was in the spring of the Yingpan sea area,reaching 27.35 ind./m²,and the lowest average habitat density was in the spring of the Lianzhou Bay sea area,only 1.00 ind./m².The dominant species in the four sea areas were significantly different in spring and autumn.The results of multiple biodiversity indices showed that the biodiversity of benthic shellfish in the Yingpan sea area in spring was poor,and the community structure of benthic shellfish was seriously disturbed.The biodiversity of benthic shellfish in the four sea areas in autumn is abundant,and the community structure of benthic shellfish in autumn was generally in a relatively healthy state.