泉州湾海域鱼类多样性及营养级变化

Changes of fish diversity and trophic levels in Quanzhou Bay

利用2008年5月和10月在泉州湾进行的拖网渔业资源调查资料,探讨了该海域鱼类群落结构和物种多样性特征。结果表明,两次拖网调查共鉴定鱼类54种,隶属于2纲13目32科。其中中上层鱼类12种,近底层鱼类19种,底层鱼类23种;暖水性鱼类40种,暖温性鱼类14种,未发现冷温性和冷水性种类;杂食性鱼类4种,低级肉食性鱼类37种,中级肉食性鱼类8种,高级肉食性鱼类5种。白姑鱼(Argyrosomus argentatus)和叫姑鱼(Johnius belengerii)是5月份最主要的优势种,凤鲚(Coiliamystus)和龙头鱼(Harpodon nehereus)是10月份最主要的优势种。与1985年的调查资料相比,泉州湾鱼类组成和优势种发生了很大的变化,多样性指数由3.05下降到2.32,均匀度指数由0.76下降到0.58,营养级指数由2.79下降到2.54。泉州湾鱼类多样性下降的主要原因可能是过度捕捞、水域污染和栖息地丧失等。

The composition and diversity of fish species in Quanzhou Bay waters are analyzed based on 2 seasonal surveys in 2008.A total of 54 fish species belonging to 32 families,13 orders and 2 classes are recorded.According to their living environment,the fishes can be grouped into 3 types,among them 12 species are pelagic fish,19 are near demersal fish and 23 demersal fish.According to temperature adaptation,the fishes can be divided into 2 types,i.e.40 species are warm water and the rest 14 are temperate warm water fish.In terms of food habit,they can be grouped into 4 types,of which 4 species of omnivores,37 lower carnivorous,8 middle carnivorous and 5 higher carnivorous.Argyrosomus argentatus and Johnius belengerii were the first dominant species in May.Then,they were replaced by Coilia mystus and Harpodon nehereus in October.Comparing with a survey in 1985,we find that the species composition and the dominant species of the bay have changed obviously.The Shannon-Wiener index decreased from 3.05 to 2.32,the Pielou evenness decreased from 0.76 to 0.58,the trophic index decreased from 2.79 to 2.54.It is suggested that factors such as overfishing,water pollution and habitat loss may have reduced the fish diversity of the bay.