The Future of Lake Greenery and Livelihoods: The Challenge of a Salaried NGO that Fought Against Blue-Green Algae in Teganuma in 2000

The Future of Lake Greenery and Livelihoods: The Challenge of a Salaried NGO that Fought Against Blue-Green Algae in Teganuma in 2000

In 2000, Teganuma in Chiba Prefecture was a symbolic lake that continued to record the "worst" water quality in Japan. The average depth of the water was less than one meter. Rapid urbanization after World War II meant that purification of domestic wastewater could not keep pace, and eutrophication caused by phosphorus and nitrogen was progressing. In summer, algae called "blue-green algae" covered the surface of the lake, emitting a putrid smell and depriving fish and other aquatic life of a habitat.

Against this backdrop, Haruo Fujimoto, then in his late 30s, was a unique activist, a company employee, karate instructor, and environmental NGO representative. The "Soft Energy Research Group," which he led, emphasized "practice" rather than enlightenment, and its motto was "weekend research and technological development.

Mr. Fujimoto's focus was on the current situation, which he recognized could not be solved by conventional administrative measures, namely sewerage maintenance and phosphorus removal. He then turned the tables and started from the idea that "blue-green algae itself is a resource. This idea of blue-green algae as a resource rather than a pollutant resonated with the atmosphere of the time, when the need for sustainability and a recycling-oriented society was beginning to be called for.

He developed the "Blue-green algae buster," a device that uses ultrasonic waves to destroy the gas vesicles of blue-green algae, causing them to lose their buoyancy and settle. The device was a low-cost invention that utilized recycled materials: a handmade cylindrical waveguide with an ultrasonic transducer and a PET bottle attached to a wooden pallet. The device consumed less than 30 watts of electricity per unit and was extremely energy efficient.

Mr. Fujimoto also came up with the concept of "farming on the lake. Using the nutrients from the blue-green algae, he succeeded in growing kuwai and water spinach. The safety of the method has been confirmed by Chiba University. Crushed shells are placed on the surface of the water to allow the roots to grow. This was an attempt to convert "eutrophication" into "liquid fertilizer," and was innovative in that it "took an environmental problem and turned it on its head.

Behind this was his yearning for a "comfortable life" that he had experienced living in Spain when he was a student there. Growing up during Japan's period of rapid economic growth, he questioned the efficiency and competition of the Japanese lifestyle and turned to environmental technology as a means of pursuing a "rich and sustainable lifestyle.

The year 2000 was just as the effects of the Kyoto Protocol (COP3, 1997) were taking shape, and terms such as "sustainable society" and "circular economy" were beginning to permeate both policy and business. Local governments were lagging behind in the development of sewage systems and struggling to receive government support, but a model such as Fujimoto's, where citizens took the lead in technological development, was extremely pioneering.

Mr. Fujimoto's activities are not simply about nature conservation. It was a "redesign of life" that aimed to reintegrate technology and life. Resource recycling, the relationship between the city and nature, and the connection between professional and civic activities - all of these activities pioneered the environmental movement and regional revitalization that began in the 2000s, and they remain highly significant today.