Tokyo is the site for the world's largest fish market, a place famous for the ultra-high quality tuna featured at the city's best sushi restaurants.

Our friend Madeleine Brand is on assignment in Japan right now, she is doing stories for our Climate Connection Series. And while she is in Tokyo ,she's gone by the world's largest fish market. It's a place famous for the ultrahigh quality tuna featured at Tokyo's best sushi restaurants.

The demand for tuna is so great now that even though it seems like there is a glut of tuna standing in Tsukiji fish market. Just looking at the hundreds of tuna lying here on pallets, they really are being overfished and it is a big problem for the tuna worldwide.

Now Madeleine doesn't really know her way around this market yet, so she went with a guide. His name is Tim Horniac. He's a freelance writer , a big sushi fan , he had all kinds of statistics about the fish in this market fished from all over the world.

2,500 tons of fish worth over 23 million dollars are sold here everyday. And tuna can fetch prices up to 20 million yen, which, correct me if I'm wrong, is something like 200,000 dollars for a single fish.

Feel kind of sorry for them lying here. They look like sad little corpses with their tails cut off, a big gash under their fin.

And you can see the tails are sliced off, in kind of 90-degree-angle cuts so that the traders can directly inspect the meat with their flashlight and they're looking for the freshest fattest tuna that will fetch the highest price.

OK, and this is where it all ends up ,we are sitting in a sushi restaurant right next to the fish market,it is 7 o'clock in the morning and we are having sushi.

This is the best sushi in the world, right here, Tsukiji fish market, Ground Zero for sushi. Hey, eat your heart out, Alex, coz I am about to eat some delicious sushi. Bye-bye, sayonara!

Madeleine Brand enjoying a sushi breakfast with Tim Horniac at the Tsukiji fish market in Tokyo.