Why is Japanese tuna so expensive?

Can you elaborate on the reasons behind the skyrocketing prices of Japanese tuna? Are there specific factors contributing to its high demand, such as its rarity, quality, or cultural significance? Are there any environmental concerns or sustainability issues that also play a role in the market price? Lastly, what impact does the global seafood trade have on the pricing of Japanese tuna, and how does it compare to other premium seafood options?