Man strikes again! Our desire to focus on meat for the main portion of meals has led to the over-fishing of bluefin tuna in our oceans. I hope that you really like your sushi!
Bluefin tuna is at the top of the food chain and its largest predator is...man. Unfortunately, since the bluefin tuna resides in mostly open ocean waters no one nation is in charge of monitoring the fishing of the tuna. Japan, surprise, surprise, is one of the main offenders of overfishing of this species. Japan also overfishes whales in the name of "research." (side note, I highly recommend watching "Whale Wars" about that topic).
Some countries are recognizing this problem and have tried to take steps to put the species on a protected list, but even if the fishing stopped entirely it seems unlikely that the species could recover. Unbelievably some sushi restaurants still serve bluefin - like Nobu. Many top sushi restaurants have banned bluefin tuna on their menus. My hope is if there is less demand the supply will have to go down, list or not.
I hope that people can be more aware of their food choices and what choices are sustainable and not.