I ate California rolls, I feel so bad after my best friend said not to eat seafood! Is it bad that I ate California rolls???
You actually have a higher chance of getting listeria from cauliflower and spinach; you can research and find all the data that compares actual sushi (which is raw fish and rice, not any kind of roll) to certain food groups. Women in Japan are encouraged to eat sushi because of all the nutritional benefits that fish contains (not the fish that is high in Mercury). Just make sure it comes from a clean restaurant that you trust and have eaten at before and it's completely okay
you only have to worry about large seafood, such as shark or swordfish. it's the large fish like that which are a danger, because they contain more mercury. don't worry, especially if your fish is cooked, you should be ok.
Also, a California roll typically doesn't have any raw fish in it. The "crab" is usually imitation crab and it's fully cooked.