Lake Shinji is one of the largest brackish lakes in Japan, located in the eastern part of Shimane Prefecture. It is connected to its neighboring lake, Lake Nakaumi, and its salinity fluctuates between 1 and 10 PSU, depending on weather conditions, as well as tidal influences.
Lake Shinji is blessed with abundant marine resources, including whitebait, shrimp, and eels, collectively known as the "Seven Treasures of Lake Shinji." In particular, the lake ranks first in Japan for its basket clams catch.
In 2005, Lake Shinji and Lake Nakaumi were designated as a Ramsar Convention wetland, as tens of thousands of waterfowl of about 20 species migrate to the lakes each year, attracted by their rich environment and abundant resources. Public and private sectors are working together to promote the conservation, restoration, and sustainable use of the lakes, while also fostering exchange and learning opportunities to support these efforts.
In the past, Lake Shinji suffered from eutrophication due to modernization, changes in living environments, and the development of economic activities. However, in 1989, a lake water quality conservation plan was formulated. Since then, comprehensive and systematic measures have been implemented, including the construction of sewage treatment facilities, initiatives to reduce pollution loads, and efforts to raise public awareness among residents. These activities have been carried out through collaboration between the public and private sectors.
In addition to setting water quality targets, the plan establishes evaluation indicators through a lake environment check that engages the five senses—sight, hearing, smell, taste, and touch—making it easier for residents to become familiar with and actively participate in the initiative.
In the past, there were efforts to desalinate Lake Shinji and Lake Nakaumi in order to create agricultural land. However, due to opposition from residents who were concerned about the deterioration of water quality, the desalination plan was canceled in 2002.
Lake Shinji is also renowned as a tourist destination, particularly for its spectacular sunsets, attracting many visitors throughout the year. The lakeside area is home to the Shimane Prefectural Art Museum, which celebrates harmony with water. It also hosts the Lake Shinji Nature Museum Gobius, along with numerous parks and waterfront areas that offer recreational activities such as sailing and boating, attracting both tourists and residents.
Lake Shinji is thus an irreplaceable asset that provides people with numerous benefits, including excellent scenery, rich fisheries resources, and tourism opportunities.