What makes fish sushi grade?!
Answers: How do I handle it? where should I get it from?
Sushi grade cannot come into contact with any other fish, shell fish etc. It's frozen and used specifically for sushi and sashimi. Look at Markets, upscale grocery stores
Freshness and location where it is from.
Handle it like any fish, keep it tightly wrapped, it should not smell fishy at all. Get it from a fish market or notable food shop.
Sushi or Sashimi-Grade Fish
Despite popular belief, there is no official definition for the term "sushi-grade". The Food and Drug Administration (FDA) does not determine safety standards for raw fish.
In order for seafood to be safe for consumption in sushi, it must be frozen at under -4°F for a significant enough time to have killed any parasites.
Although many markets are starting to carry Sashimi-grade fish, you should not assume that all fish from your local market has gone through the necessary steps to destroy parasites. Do not assume that fish is safe to eat raw unless it is clearly labeled as "Sashimi-Grade".
it is its freshness that is of paramount importance as it is eaten raw so stale fish is of no use as you do not know what bacteria,s are on the fish.
as for where you can get the fish from well from a reputable fish monger and you could try going to a fishing port or village and see whats on offer