In December 2022, the “Act on Ensuring the Proper Domestic Distribution and Importation of Specified Aquatic Animals and Plants” came into effect. The Act aims to prevent illegally catught or gathered aquatic animals and plants from mingling in the distribution process, as well as to stop the flow of the catches derived from IUU fishing into the Japanese market. The Act requires fishers and business operators who handle the specified aquatic animals and plants to notify the administrative agencies, communicate catch numbers, make and keep transaction records, and attach certificates at the time of import or export in order to ensure the proper domestic distribution of the aquatic animals and plants.

Although the Seto Inland Sea’s water quality has improved, the sea has become oligotrophic (nutrient deficient) due to a decrease in the nitrogen concentration, which is essential for biological production. As a result, the color of farmed nori seaweed has been fading and fish catches have been declining, leading to decreasing richness of life in the sea. We investigated the relationship between declining ikanago (Pacific sand lance) catches and oligotrophication, and proposed how oligotrophication is the starting point for a declining scenario. In order to restore the sea’s richness, the national and prefectural governments have revised laws and ordinances and have begun managing nutrient salts.

From the Azuchi-Momoyama period to the Edo period in the 16th century, Japan, as a maritime nation utilized the sea and ships to procure goods and developed infrastructures to build huge early-modern castle towns. Edo, meaning "the gateway from the river to the sea," was a maritime capital where trade, logistics, and other economic activities flourished. Historical urban planning from the Edo period had played a crucial role in the background behind Tokyo’s transformation into a modern city known for its efficient transportation network, culture, businesses, and liveliness.