Abstract
The purpose of this study is to explore changes in the time-series and area-by-area conservation efforts and to consider the relationship with the habitat status of Tanakia lanceolate in Fujioka City, Gunma Prefecture. It is intended that the knowledge obtained will be used to maintain/increase the population and expand the habitat of Tanakia lanceolate. Since 2000, Tanakia lanceolate lived mainly in Shimototsuka (Okanogo irrigation canal) in Sasagawa, Fujioka City. Ex-situ conservation has been implemented due to population decline and farmland development projects currently it inhabits two locations: Hongo and Yaba in Sasagawa. In this study, we first set up a hypothesis that the agricultural infrastructure such as the waterways as the habitat for Tanakia lanceolate in Fujioka City and the efforts of people to the Tanakia lanceolate affect its habitat. Focusing on the transition of conservation efforts over 20 years, we organized and analyzed them in each area chronologically then considered the impact on their habitat. As a result, it was revealed that four types of conservation efforts have contributed to escape the threat of extinction and the species has continued to inhabit to this day. Environmentally friendly field maintenance improved the habitat environment, and aquaculture and reintroduction by the Fisheries Experimental Station continued to supply ex-situ conservation and breeding of Tanakia lanceolate. In addition, it has become clear that maintenance and management of the habitat by local residents, highschool students continued efforts to raise awareness have led to the existence of the Tanakia lanceolate to this day. To confirm the habitat of Tanakia lanceolate in this prefecture led to the designation as a natural symbol and enabled a conservation group to be established. It has become clear that the conservation efforts have been continuing with citizen participation.
