I asked the family doctor and he was of minimal help sadly but i did find this....
i -knew- there was something i heard about curing....
1. What do I need to know about buying fresh fish?
Good question. Let me just give you a few pointers about finding fresh fish...
The best thing to do is to approach your local sushi chefs to find out where their buyers go to get their fish. You won't be able to buy it from a distributor usually because you aren't buying in bulk like a restaurant would, however, they may be able to tell you the best places for smaller quantities. The most important thing to look for is that the fish has a sheen to it, not dull. If you go to reputable place, you don't have to worry about the quality of the fish. It will be pre-packaged most likely in smaller quantities and dated. If you have to travel any distance to get the fish, be prepared to transport the fish in a cooler. Use ice packs and not ice cubes because the water from the ice will ruin the fish. Stay away from salmon unless it is smoked. You are better off going with tuna, yellowtail, shrimp, crab.
2. What about bacteria in fresh fish? Do I need to be concerned?
The one fish to be concerned about is salmon. It needs to be cured. To make salmon safe, salt it for an hour (both sides covered with salt, skin and meat sides), rinse with cold water and soak in a white wine for 20 minutes. Then freeze for a minimum of 24 hours, preferably 48 hours.
i bet Sake is used instead of white wine..
http://www.stickyrice.com/sushi/faqs/faqs.html