Japan's agriculture, forestry and fishery accounted for 4 1% in 1885, and decreased to 20% in 1940. Accordingly, the manufacturing, mining and construction industries only accounted for 10% in 1885, and rose to 40% in 1940, which can be said to be basic industrialization.

This is also the capital for Japan to launch the Second World War. After World War II, the proportion of agriculture, forestry and fishery in Japan decreased from 33% in 1945 to 6% in 1970, and the proportion of manufacturing, mining and construction increased from 29% in 1945 to 46% in 1970, and it was industrialized again, reaching/kloc.

Reasons for the emergence of Japanese fisheries:

Hokkaido fishing ground is located at the intersection of Japanese warm current and Thousand Island cold current. Due to the difference of seawater density, the cold water with high density sinks and the warm water with low density rises, which leads to the vertical agitation of seawater, bringing the organic matter deposited on the seabed to the surface, providing rich bait for fish, and gathering cold water fish and warm water fish here, thus making this sea area a world-famous fishing ground.

The confluence of cold current and warm current can disturb the seawater, and the flooded seawater brings nutrients to the ocean surface, which makes plankton flourish, thus providing rich bait for fish and enriching fishery resources. In addition, the confluence of cold current and warm current can form a "water barrier" to prevent fish from swimming, and it has become the largest fishing ground in the world because of the advanced technology of fishing industry and the developed aquaculture fishery in the country.