The project aims to collect data on radiation levels in the marine environment of the North Pacific saury fishing grounds. It is planned to conduct sample collection in the area ranging from 37.5 degrees to 41.5 degrees latitude and 152.5 degrees to 153.5 degrees longitude in the North Pacific. The project includes six sampling stations, and at each station, water samples will be collected at four different depths. The sampling depths will be determined based on the habitat depth of saury and the depth of the Japanese tritium water release undersea tunnel. The planned depths for water collection are 5m, 15m, 100m, and 200m. In addition, a plankton sampling net (ORI net) will be used to collect planktonic organisms to assess the radiation levels of food organisms in the area. The collected samples, including water at different depths and planktonic organisms, will be analyzed for radiation levels. The goal is to obtain the test results and data on radiation detection values in the marine environment of our country's offshore fisheries.