Essential characteristics of aquatic environment for ayu habitats
Essential characteristics of aquatic environment for ayu habitats
复制标题
香鱼栖息地水生环境的基本特征
DOI：
10.2331/suisan.15-00027
复制
发表时间：
2016
影响因子：
0.4
通讯作者：
Y. Takagi
中科院分区：
文献类型：
--
作者：
J. Tsuboi;Y. Takagi
本研究在日本北海道、本州和九州的25条河流中，用通气管潜入水中，对香鱼的个体数量和微生境进行了测定，并对香鱼种群建立的基本要素进行了调查。在我们的分析中，选择三个因素作为观测到的香鱼数量的解释变量：1）较小的河流宽度，2）河床上巨石（长轴超过25 cm）的频率较高，3）暴露巨石的频率较高。在对放养地点作出管理决定时，应考虑到这些因素。通过浮潜观察到的香鱼个体数量也与纳卡河中"Tomozuri'"垂钓的每单位渔获量呈正相关。因此，通过水下观测计数的个体数可能是作为垂钓目标的香鱼丰度的适当指标。
We investigated essential factors of the establishment of stocked ayu, Plecoglossus altivelis by going underwater with a snorkel to count the number of ayu individuals and measure the microhabitat in 25 rivers in Hokkaido, Honshu, and Kyushu. In our analysis, three factors were selected as explanatory variables for the number of ayu observed: 1) smaller river width, 2) higher frequency of boulders (over 25 cm in major axis) on the river bed, and 3) higher frequency of exposed boulders. These factors should be taken into account when making management decisions on stocking sites. The number of ayu individuals observed by snorkeling also positively correlated with catch per unit eŠort of ``Tomozuri'' angling in the Naka River. Therefore, the number of individuals counted by underwater observation may be an appropriate index of the abundance of ayu as a target for angling.