Between Pollution and Regeneration - The Challenge of the Yatsushiro Sea, Kumamoto Prefecture (June 2004)

Between Pollution and Regeneration - The Challenge of the Yatsushiro Sea, Kumamoto Prefecture (June 2004)
The Yatsushiro Sea (Shiranui Sea), which stretches across southern Kumamoto Prefecture, was once known as the "Sea of Fertility" and was the economic and cultural center of the region, where a wide variety of fish and shellfish were caught. However, since the period of rapid economic growth, wastewater from coastal factories, domestic wastewater, pesticides, and chemical fertilizers have accumulated, and in the 1970s, there was a series of serious damage such as frequent red tides and fading of the color of nori seaweed.
In particular, since nori-agriculture was a pillar of the local economy, the deterioration of quality due to deteriorating water quality directly affected the livelihood of the fishermen. A strong sense of crisis spread among the local residents, and Yatsushiro City, Minamata City, and other watershed municipalities, fishermen's cooperatives, and research institutes began working together to investigate the causes and implement countermeasures.
Since the 1990s, the development of sewage systems has progressed gradually against the backdrop of the Basic Environment Law and the Water Pollution Prevention Law. In addition, the introduction of purification equipment for factory wastewater and awareness-raising for household wastewater also began in earnest. In addition, "nature restoration projects," such as the re-meandering of rivers that had once been straightened and the restoration of tidal flats, were introduced, and attempts to restore the ecosystem of the Yatsushiro Sea began.
Even so, sludge remains in the deeper layers of the seafloor, and the problem of "internal loading," the excess of nutrients due to the accumulation of nitrogen and phosphorus, is deep-rooted; as of 2004, red tides continued to occur as the water temperature rose during the summer, and full recovery has not yet been achieved. However, with the progress of community-participatory surveys and environmental education for children, the attitude of "local communities to reclaim their own seas" has been spreading.
The restoration of the Yatsushiro Sea is a microcosm of issues common to inner bays throughout Japan, and as an advanced case study in the search for symbiosis between industry and fishery, and between cities and nature, it symbolizes a turning point in environmental policy.