Fish Spatial Distribution and Biomass Assessment in Yudong Reservoir of Yunnan Province Based on Hydroacoustic Research
SHI Ni;LI Yingwen;Chongqing Engineering Research Center of Bioactive Substances,Chongqing Key Laboratory of Zoobiology,College of Life Sciences,Chongqing Normal University;
[Purposes]In order to understand the spatial distribution and existing resources of fish in Yudong reservoir of Yunnan province.[Methods]In July 2017,a water acoustic survey was carried out by using Simrad EY60 echo detector in the study area.[Findings]The density of fish in Yudong reservoir is unevenly distributed,and most fish are concentrated in the upper layer of water.The upstream fish density is 447.1×10~(-3) individuals·m~(-3).The detected target strength range of the whole section of the reservoir is -37~-70 dB,corresponding fish body length range is 1.25~55.59 cm.According to the formula,the fish biomass in the upper,middle and lower reaches of the reservoir is 0.17×10~(-3),0.06×10~(-3),and 0.03×10~(-3) kg·m~(-3),respectively.Preliminary estimates of the overall amount of fishery resources are 12 697 kg,The number of fish that can be caught are 2 847 823 individuals.[Conclusions]The spatial distribution of fishery resources in Yudong reservoir is not uniform,mainly concentrated in the upper layer of water body.This is related to factors such as predation pressure,fish habits,water temperature and dissolved oxygen.
【CateGory Index】： S931