Thursday, May 1, 2014

What is marimo?

Marimo (まりも), also known as Cladophora ball, or moss balls, is a rare form of green algae, found in some of the lakes in the northern hemisphere. They are known for their green velvety round shapes. Dr. Anton E. Sauter first discovered them in 1823 in Lake Zeller, Austria. Mostly found in Lake Akan (Japan) and Lake Mývatn (Iceland), the number of Marimos has been decreasing rapidly. As such, they are declared protected species in Japan and Iceland. Japan has also declared Marimo its national treasure in 1921, and thereafter “special national treasure” in 1952. Find out more about this ultra-cute ball of moss!  Marimo grows at a slow rate of about 5mm per year. However, in Lake Akan, the Marimos are said to be able to grow up to 20-30 cm in diameter!

Marimo Festival in Japan In attempt to preserve the rapidly declining number of Marimos in Lake Akan (due to deforestation, tourism etc), a movement was started to encourage the people in Japan to return the Marimos they have purchased or taken from Lake Akan. The Marimo Festival started out as a form of appreciation towards those who have returned the Marimos, as well as to extend the efforts of preservation. The first festival was held on 7th Oct 1950. Thereafter, each year in early October, the 3-day festival is held in Hokkaido by the indigenous Ainu people. On the first day of the festival, lectures on the growth of Marimos and field trips to their habitats are held. On the second day, a dance parade, “Ceremony for Receiving Marimo” and “Ceremony to Conserve Marimo” are held. These ceremonies are performed in accordance to the traditional Ainu practices. The festival closes with the ceremony of an Ainu chief returning the Marimos to the lake. There will also be fireworks displays and other game attractions during the 3-day period. If you have the chance to go to Hokkaido during this period, do drop by and join in the festival!

How to care for it
  • Keep your domestic Marimo in a jar or tank of water under indoor lighting and in water temperature of between 20 – 28°C. Do not put it under direct sunlight or heat.
  • Change water every 2 weeks. You can use tap-water but leave the container of tap water uncovered overnight for the chlorine to dissipate before use.
  • Gently clean the Marimo when you change the water by rolling it around in your hand and gently squeezing it to get the dirty water out. Rolling the Marimo also helps to keep it in a spherical shape. In the natural environment, the water current in the lake keeps the Marimos clean and helps maintain their spherical shapes.

Consider decorating your office table or room with a Marimo or two. It is fuss-free and easy to manage. But beware of fake Marimos sold on the internet. These fake Marimos are usually Styrofoam balls wrapped with green moss.

You may find the Marimo Seller at this few website: (English Version) (Chinese Version)