Hydroacoustic survey of fish resource and spatial distribution in Hongfeng Lake

We observed the fish resource in Hongfeng Lake in Guiyang cityduring September~December, 2010 andApril~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 (51.6436.49)10-3 indm-3 and significant difference in fish density is found in different areas, with the maximum at Zone Jiangjunwan (97.2512.35)10-3 indm-3 and the minimum at Zone Daba (14.902.56)10-3 indm-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 differentamong different water layers.