The study of amphipods in rimstone pools of Akiyoshi-do Cave, Japan

Akiyoshi-do Cave is the largest show cave in Japan and has been recognised as a hotspot of cave animals due to their diversity in species. Human-induced alterations in the cave environment have been a significant concern catching the attention of tourists and managers. Previous studies indicated water quality alteration induced by tourism could affect the population densities of amphipods. However, no study went further than qualitative observation in terms of human impacts. This study targets two amphipods living in Akiyoshi-do Cave, Pseudocrangonyx akatsukai and Gammarus nipponensis and measures water characteristics in which they live. Results show that the population densities of the amphipods have decreased compared to the 1970s. Their living habitat has changed, probably induced by tourism.