论文部分内容阅读
2006年8月16-18日通过使用回声探测仪(Simrad公司EY60型,200kHz换能器)对青海湖的鱼类资源进行了探测评估.结果表明:青海湖裸鲤(Gymnocypris przewalski)水平分布具不均匀性,有小型鱼群聚集现象;在不同的设定分区,鱼类密度在0.168-12.8ind./1000m~3之间,均值为1.16 ind./1000m~3;布哈河口鱼类较为密集,密度最大值为12.8ind./1000m~3.初步估算青海湖裸鲤达可捕规格(体长大于20cm)个体数量为6.5×10~7ind.,95%置信度区间为35.6×10~7-118.4×10~7ind.,应用资源密度体积法估算青海湖裸鲤的可捕资源量约为1 5275t.探测实验还证实,EY60回声探测仪在青海湖中进行鱼类资源评估时探测效果良好,分析软件Sonar5可以对鱼类个体自动识别、计数,便于进行鱼类资源量评估.“,”A SlMRAD EY60 echo-sounder with 200kHz split-beam transducer was used to survey the fish school in Lake Qinghai on August 16-18, 2006. The transducer was tied on the side of the ship downward at one meter depth. The cruising speed is 8-10km/h. Also, a GPS was connected with EY60 echo-sounder for obtaining the survey position data. The pulse duration was set at 64μs. At post-processing, the Sonar5-pro software (versions 5.9.6) was used to analyze the echo-sounder data. The results show that the Gymnacypris przewalskii is not uniform distribution in horizontal direction in Lake Qinghai, and appears the feature of small aggregation. For different survey subarea, the density of fish is 0.168-12.S ind./1000m~3, and the average is 1.16ind./1000m~3 where the maximum appeared near the Buha estuary. The biomass of catchable size is estimated at 6.5×10~7 ind. near 15275 ton, at 35.6×10~7-118.4×10~7 ind. with 95% confidence interval. Our results also indicated that the EY60 echo-sounder is suitably applicable in Lake Qinghai to estimate the fish productions effectively.