If you are one of those people who have a stereotype perception of Japan as a country with hustle and bustle, you will be surprised to hear that nearly 70% of Japan's total land area is covered with mountains and that there are numerous lakes in the mountains.
Lake Akan (阿寒湖), another lake in Akan National Park (阿寒国立公園) located in the eastern part of Hokkaido (北海道), belongs to such numerous lakes of Japan. Unlike other lakes, however, Lake Akan is famous for the lake balls known as 'marimo' (マリモ).
The marimo or the most peculiar and scientifically interesting balls made up of green algae can be found only in few lakes in the world such as Lake Myvatn in Iceland and Lake Akan in Japan. Though similar lake balls have recently been discovered in other lakes in Russia and Europe, the spread is limited to the Northern Hemisphere. It is quite possible that 'marimo" of Lake Akan is the origin of all such balls. An opinion has it that migratory birds ate them and brought them to other areas. Who knows?
The marimo has no core in the centre, but the algae filaments grow in all directions from the centre of the ball. The spherical shape of the algae is created over the decades by the constant wave motion of the lake.
The lake ball was only discovered as late as 1897 by a professor of Sapporo Agricultural School and has been protected as a natural monument since 1952. In fact, it is listed in the Red List of the Environment Agency as endangered species.
The marimo can withstand very low temperatures and stay alive even under the 60 cm thick ice of the lake which freezes completely in winter. Left alone for centuries, it can reach the size of soccer balls.
