Sean, I would suggest that especially in light of global pollution, overfishing, the incredibly high
price of fish (which is making the market in illegally-taken, intentionally mislabelled, and sometimes toxic fish very profitable)...Enjoy buy enjoy it with great caution.
When it comes to shellfish (you did mention scallops, that ain't fish[g]) you CANNOT eat them unless you know or trust the source. That means either taking them in waters you know are clean, or
buying them from a reputable source--and even they sometimes are deceived by their suppliers.
Scrombroid poisoning means someone didn't handle the fish properly. My parents generation was taught to defrost frozen fish and poultry by leaving it in the
fridge overnight or leaving it on the counter--at room temperature. Today, if you check the USDA web site or any other, they'll tell you very clearly NEVER LEAVE IT ON THE COUNTER. Not at all, not for any time. And it used to be normal to defrost poultry on a tray, cook it, and them serve it on the same tray. Again, we know better now--but lots of folks say "Well I never got sick so why should I..."
Add
cheap labor and distributors who don't handle
food (shellfish, fish, poultry, whatever) properly and it comes down to the fact that you really have to trust someone before you buy or take
food from them.
I like to joke that southern fried chicken is
health food: What can survive pressure
cooking in boiling oil?<G> Except the scrombroid toxins, maybe.
But ciguatera...I thought someone was working on a test strip to test for that, and in the meantime the word was to avoid certain species (like barracuda) that are prone to it, and check for local knowledge to find out if it is a problem in the area.
I still prefer fish taken right off the spear and cooked on the beach: Makes the cleanup easier, too. Totally eliminates the "how was it handled" issues, too. If I walk into a fish store and it smells like fish (i.e. has ANY odor) I'll walk right out again, I'm just not willing to gamble that way.