Harimanada, Hyogo, bottom trawling and marine pollution (June 2004)

Harimanada, Hyogo, bottom trawling and marine pollution (June 2004)

In 2004, the Harimanada Sea, which stretches across southern Hyogo Prefecture, was known as a rich inner bay fishing ground due to its unique currents and topography, even though it belongs to the Seto Inland Sea. However, the effects of the period of rapid economic growth that began in the 1970s were still leaving serious scars on the local environment and industry decades later.

While bottom trawling can catch large quantities of bottom-dwelling seafood such as shrimp and flounder, it is a fishing method that physically destroys the ecosystem of the seafloor and has been blamed for overfishing and resource depletion. This fishing method was particularly widespread in the Harimanada Sea, and by the late 1990s, the number of fish species was declining and their size was decreasing significantly, raising questions about the sustainability of the fishery.

In addition, wastewater from steel and chemical plants in the coastal industrial areas of Kakogawa, Takasago, and Himeji has been flowing into the sea for many years. This led to eutrophication of the seawater, causing frequent problems such as red tides and accumulation of heavy metals in shellfish. Water quality surveys conducted by the Environment Agency (at the time) recorded some areas of the Harima Sea as "sea areas that did not meet environmental standards.

In 2004, against the backdrop of such a fishery crisis and environmental pollution, fishing cooperatives, NPOs, and citizen groups were attempting to monitor, voluntarily regulate bottom trawling, and introduce environmental education. At the same time, there were strong demands from local and national governments for stricter effluent regulations for companies and budgetary measures for environmental restoration projects, which were also discussed in the Diet.

For local residents who "live off the sea," the natural environment is not just a landscape, but the very foundation of their lives. The problems surrounding the Harima Sea symbolize the fact that the bill for environmental destruction continues to affect people's lives even after several decades.

Related links:
- Hyogo Prefecture: Water quality and environmental measures in Harimanada
https://web.pref.hyogo.lg.jp/nk15/nk15_000000002.html
- Ministry of Land, Infrastructure, Transport and Tourism: Harimanada Comprehensive Marine Environment Improvement Project
https://www.mlit.go.jp/kowan/kowan_tk6_000013.html