Sometimes it's a little sad when you find what you're looking for.
I went to the fish market this morning at 4:45am. My three cabmates and I practiced how to say, "fish market" in Japanese (only about 1% of taxi drivers speak English), but the employee at the taxi stand laughed and said tourists are only up at that time of the morning if they're going to the fish market. The cab was clean, and the streets were quiet. The fish market is enormous, taking about 10 minutes to walk from one side to the other. Most of the market is a mix of shack-looking stands undercover like a warehouse, but without sides. The tuna auction is the big draw, and I probably heard 15 different languages while crammed in the visitor area watching the men (it was all men working in the market) examine the frozen tuna.In general, I seemed to be the only one who was a little nausous from the blood; others were taking video of the intricate knife slicings involved in the killing. (Kiba, budding sushi chef, I think from the freshness of the fish and the style of the slicing techniques that this might be your type of place.) I couldn't take the box of giant (2+inch) eyes that had been dismembered from fish.
I didn't know that they import seafood from around the world, including MD blue crabs. It makes the whole endeavor seem less sustainable. The fish isn't necessarily fresh, fossil fuels aplenty are used, and don't even get me started on the walls of styrofoam boxes. It certainly felt like an authentic experience (in a way that Pike Place market doesn't to me), even though I just might not have seen how it's regulated behind the scenes.