Abstract
Marimo is a spherical algae, which consists of freshwater filamentous green algae, in Lake Akan. The process for making a spherical algae, whose diameter is up to 30 cm, has not been clarified. Although Marimo is registered as a nationally protected speices, the number of Marimo has been revealed to decrease. Wind wave is considered as one of the most significant factors for a formation of Marimo. However, the mechanisms of the formation have not been clarified, which could provide policies how to protect Marimo in Lake Akan. This study thus aims to investigate how a spherical shape is formed under wind wave conditions by using video camera, wave measurements, and meteolorogical observations. As a result, wind wave is revealed to be one of the significant factors that form Marimo in Lake Akan.
