The feeding habits of the society will change. The society will generally start moving away from eating raw oyster to embracing cooked oysters. In addition , people in the society will shun eating the oysters during the warm months of April and November and therefore fishing for the oysters during these months may decline.
The earth has an area called the Ring of Fire because there is a 'ring' of volcanic activity created by border between the Pacific tectonic plate and 6 others.
Early society Japan was isolated due to geographic isolation from the rest of the world, which basically means that due to natural barriers between other civilizations. (in this case, natural barrier of oceans since Japan is a chain of islands or an archipelago)
