2004 Volume 48 Pages 1573-1578
In order to evaluate the habitat of the fish inhabiting the river, it is necessary to know the relation between the amount of habitations of a fish, and the physical characteristic of a habitat “National Censes on River Environment” contains information about plants and animals as well as the physical features of rivers in a certain format. In the present study, the dominant physical attributes forming a fish habitat in various rivers of the large area in Japan are discussed by using the above database.
The population of fishes (for example Carassius gibelio langsdolfi) and physical characteristic in each river are approximated by a regression function which is derived from a multiple regression analysis. Contribution of the physical characteristic to the quantity of fishes in a different district is compared, and the feature for every area is described. And district feature is described by result from a principal component analysis. CPUE (Catch per Unit Effort) is proposed to standardize the amount of fishes capture and is used in analysis shown above.
