Eelgrass bed creation technology The era when the seeding sheet method revived the sea Early to late 2000s

Eelgrass bed creation technology The era when the seeding sheet method revived the sea Early to late 2000s

Eelgrass has been called the cradle of the sea, supporting coastal ecosystems as a cradle for small fish and crustaceans. In Japan, however, eelgrass beds were rapidly lost in Tokyo Bay, Osaka Bay, the Seto Inland Sea, and other areas due to a combination of land reclamation and red tide deterioration during the period of rapid economic growth. From the 1970s to the 1990s, the decline became more pronounced, and fishermen and researchers felt a growing sense of crisis.

In the 2000s, the Ministry of the Environment began to strengthen its monitoring of the sea area, and in response to the international trend toward ecosystem conservation following the Kyoto Protocol, the perspective of blue carbon and ecosystem services began to spread in Japan as well. Eelgrass bed restoration has been attracting attention not only for its restoration of fishery resources, but also for its multifaceted value, including its carbon fixation effect.

The seeding sheet method emerged in this context. The conventional seedling planting method required time and money to grow seedlings, and the risk of seedlings being washed away by currents was high, limiting the potential for large-scale restoration. In the sowing sheet method, mature seeds collected in the fall are mixed with substrate material, processed into thin sheets, and placed on the seafloor in winter or early spring. As the sheet gradually decomposes, the seeds are naturally dispersed, germinating and establishing themselves in suitable locations.

The method is highly regarded for its suitability for large-scale landscaping, which reduces construction costs, work time, and maintenance, and its introduction began in the 2000s along the Shima coast of Mikawa Bay in the Seto Inland Sea. The seeding sheet method was highly evaluated as a method that draws out the regenerative power of the sea and restores eelgrass beds in a natural way.

Since then, eelgrass beds have been revalued as marine forests and have been attracting attention as a carbon storage source, leading to the creation of the sea as a tourism resource in collaboration with environmental education and local fisheries. The seeding sheet method has left a solid mark in the history of coastal zone restoration as a technology that quietly restores the lost relationship between the sea and people.