Hydroacoustic survey of fish resource and spatial distribution in Hongfeng Lake

We observed the fish resource in Hongfeng Lake in Guiyang city during September~December,2010 and April~June,2011.Twenty-eight species which belong to 4 orders and 6 families were caught.The fish body length ranges from 5.68 cm to 116.41 cm,and that in dominant body length group is 11.00~30.00 cm;small,large and medium-sized fish are in the majority.Moreover,we used BioSonics DT-X digital scientific echosounder with 200 kHz split beam transducer to investigate the fish density in June,2011.The average fish density is(51.64±36.49)×10-3 ind · m-3 and significant difference in fish density is found in different areas,with the maximum at Zone Jiangjunwan [(97.25±12.35)×10-3 ind · m-3] and the minimum at Zone Daba [(14.90±2.56)×10-3 ind · m-3].From Daba to Jiangjunwan,the density of fish resource shows an increasing trend.The fish mainly distribute in 6~15 m.The fish density is signifcantly different among different water layers.