During the early modern period, Tachi-ryo (strip-shaped nets to keep schools of fish entering a bay from exiting to the open sea) was a popular method for catching migratory fish in Suruga Bay of Shizuoka Prefecture, particularly in Uchiura Bay to the northeast. As long as there were schools of migrating fish, Tachi-ryo made it possible to efficiently capture them in large amounts. At the same time, this method had a past of being at the mercy of fluctuating migratory fish numbers. What impacts did these changes have on how resources were used in these regions which were comprised of forests and cultivated land? Given that changes in migratory fish resources are linked to climate change, I would like to describe the history behind the environments of those regions, with Suruga Bay and Uchiura Bay in early modern times as examples.