STATISTIC ANALYSIS ON THE RELATIONS BETWEEN PHYSICAL ATTRIBUTES AND FISH HABITAT QUALITY IN THE RIVER BASED ON “NATIONAL CENSES ON RIVER ENVIRONMENT”

Abstract

To conserve fishes in river, it is important to understand what and how physical attributes are forming the habitats for fishes.“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 the Yoneshiro River and the Koyoshi River are discussed by using the above database.A discriminant analysis shows that the possibility to be a habitat for Oncorhynchus masou or Plecoglossus altivelis in the Yoneshioro River can be predicted by the physical attributes. The population of Plecoglossus altivelis in the Yoneshiro River is approximated by an regression function which is derived from a multi regression analysis. A comparisons of the regression function for the Yoneshiro River to that for the Koyoshi River which is the nearest river to the Yoneshiro River shows that the contributions of each physical attribute are different in two rivers while the dominant attributes are same.