长江上游干流三层流刺网渔获物结构研究

利用2010—2012年长江上游宜宾和江津江段三层流刺网渔获物的调查数据,分析了三层流刺网的主要捕捞对象和个体大小,阐述长江上游干流渔获物结构现状。结果显示,鱼类样本共计673.32 kg,分属4目9科47种;其中,鲤科鱼类占比最大,为61.70%,其次是鲿科,为10.64%,长江上游特有鱼类11种,占鱼类总种数的23.40%。主要捕捞渔获对象多为未达到性成熟的个体。对宜宾和江津两江段三层流刺网渔获物种类、物种相似度和生物多样性指数进行了比较分析,宜宾江段鱼类39种(含特有鱼类8种),分属4目8科,江津江段鱼类40种(含特有鱼类11种),分属4目9科;江津江段渔获种类和特有鱼类数量均高于宜宾江段,宜宾和江津两个江段三层流刺网的鱼类物种相似度为81.01%;宜宾江段物种多样性指数为2.81,略高于江津江段的2.76,但两江段的多样性指数无显著差异。通过本次研究可以为分析向家坝等水电站蓄水对长江上游鱼类的影响提供数据参考,同时也为长江上游鱼类资源的保护和渔业规划提供依据。

Study on structure of gillnet catches in the upper reaches of the Yangtze River

The catch data from 2010 to 2012 in Yibin and Jiangjin section were analyzed to understand the status of gillnet catches in the upper reaches of the Yangtze River. A total of 673. 32 kg catches belonging to 4 orders, 9 families, 47 spe-cies were collected. Among them, the Cyprinidae accounted for the largest, 61. 70%, followed by Bagrid, 10. 64%. 11 species of fish which were endemic to the upper reaches of the Yangtze River accouted for 23. 40% of the total. The gillnet catches were mainly the juveniles of fish. The different types of species, similarity and biodiversity index in Yibin and Jiangjin gillnet catches were compared and analyzed. The results showed that, 39 species of fish collected in Yibin be-longed to 4 orders, 8 families, and 8 species of fish were endemic to the upper reaches of the Yangtze River; 40 species of fish collected in Jiangjin belonged to 4 orders, 9 families, 11 species of fish were endemic to the upper reaches of the Yangtze River. The fish species and endemic species in Yibin were more than Jiangjin. The fish species similarity of both sections was 81. 01%. The species diversity index of gillnet catches in Yibin was higher than that in Jiangjin, but had no significant difference. This investigation could be referenced to analyze the potential influence of Xiangjiaba Reservoir on the fish resources of the upper Yangtze River and provide scientific basis for protecting and managing the fish resources of the Yangtze River.