闽南-台湾浅滩渔场中上层趋光鱼类群聚结构的时间变化

STUDIES ON THE TEMPORAL VARIATION IN PELAGIC PHOTOTACTIC FISH COMMUNITY STRUCTURE IN THE FISHING GROUND OF THE SOUTHERN FUJIAN AND TAIWAN BANK

闽南-台湾浅滩渔场位子印度—西太平洋暖水性动物区系马来亚区北部。该渔场中上层鱼类种类多,数量也较大,在渔业上有一定地位。本文据厦门市1973—1980年共八年的逐月机帆船光诱围网渔获物组成和产量(其中1979年11月缺),及相应年、月生产船数和日数的统计资料,分析该海域中上层趋光性鱼类的群聚结构特点及其时间变化,并探讨了多样性指数、均匀度、鱼种数、最大多样性指数和优势种数诸特征值与资源量指标值(CPUE)的关系,以供海洋鱼类群聚生态研究和渔业生产管理参考。

The pelagic phototatic fish community in the fishing ground of the southern Fujian and Taiwan Bank is more independent than the others.According to the monthly statistical data from the year 1973 to 1980,temporal variation of charac ter values in the fish community structure was analysed and the results show that in this community,sixteen species have been seen more often.The species which have the biomass accounting for 0.20-0.60 of the total biomass from the community are defined as the dominant species,accordingly six species were defined.Biomass of the dominant species were evidently larger in the fish community.Shannon-Wiener diversity index model was employed.Biomass was used instead of individual numbers to calculate diversity index,and the variation ranged from 1.10 to 2.75.Evenness of species varied from 0.31 to 0.77.In a same fishing period,variation trends in a year of character values in the community structure were on the whole correspondent,but they differed from each other in different fishing period.Character values of yearly mean values in the year tended to in crease gradually in variation,implying a good stability in the fish community.Analysis of rank correlation and coefficient and linear regression shows an apparent correlation between evenness of species and number of the dominant species.Diversity index related to evenness of species and number of dominant species is more close than number of species,which shows a great influence of diversity index by number of species.CPUE has a obvious relation to yearly mean values of diversity index,and too,to number of dominant species and evenness of species.This indicates that in the fish community,there is a close relation depending on each other between stability and potential resource.CPUE increased with high yearly mean values of diversity index.So we can estimate variation of stability and variation trends of potential resource in the fish community according to variation trend of yearly mean values of diversity index.