厦门海域游泳生物的时空分布特征

根据2007～2008年间在厦门海域开展的游泳生物周年季节调查数据,分析了厦门海域游泳生物种类组成、数量分布特征和季节变化,结果表明,厦门海域游泳生物种类236种,其中鱼类153种（软骨鱼类11种,硬骨鱼类142种）,隶属于16目61科108属;甲壳类71种,隶属于3目21科35属;头足类12种,隶属于3目4科5属12种.游泳生物平均密度指数为1 337ind/（网.h）,平均生物量指数为19.560 kg/（网.h）.生物量优势种为叫姑鱼（Johnius belengerii）,密度优势种为鹿斑鲾（Leiognathus ruconius）.游泳生物生物量指数的季节变化为夏季〉冬季〉秋季〉春季,密度指数的季节变化为夏季〉秋季〉春季〉冬季.同时对厦门海域游泳生物多样性特征进行分析表明,不同海域生物多样性变化特征存在明显差异,多样性指数（H＇）由东向西逐步递减,即大嶝海域〉东部海域〉九龙江口及厦门港海域〉同安海域〉厦门西港海域.并讨论了多样性特征和主要优势种的区域分布特征,结果表明,受河口区复杂环境条件的影响,该海域游泳生物季节群聚优势种较为明显.游泳生物多样性特征的变化是由于各季节主要种类的优势度不同引起的.

Temporal and spatial distribution of nekton in the Xiamen Sea

The species composition and abundance distribution of nekton in the Xiamen Sea area were characterized from one year seasonal survey conducted from 2007 to 2008.Overall,236 species of nekton were identified.These included： 153 fish species,belonging to 16 orders,61 families,108 genera（11 elasmobranch species and 142 teleostean species）;71 crustacean species,belonging to 3 orders,21 families,35 genera and 12 cephalopod species,belonging to 3 orders,4 families,5 genera.The average density of nekton was 1 337 ind/（net·h） and the average biomass was 19.560 kg/（net·h）.The dominant species in terms of biomass and density were Johnius belengerii and Leiognathus ruconius,respectively.Biomass varied with season in the following order： summerwinterautumnspring;while density varied with season as follows： summerautumnspringwinter.Trends in nekton biodiversity were also analyzed.A gradual decrease in biodiversity was found from east to west,i.e.Dadeng sea areaEast Xiamen Sea areaXiamen Bay areaXiamen Tongan Sea area West Xiamen Sea area.Analysis of the biodiversity and distribution the dominant species in the Xiamen Sea area indicated the influence of the complex environmental conditions of the estuary.Notably,a number of distinct groups of species exhibited clear patterns of seasonal dominance.Variations in the biodiversity characteristics of nekton reflected the dominance of different species during different seasons.