A note concerning pre-packaged frozen fish

[chris-uk]

Another thing to pay attention to when buying "fresh" fish is that it's sometimes "previously frozen," and not actually fresh. The salmon fillets I bought at the seafood counter in the supermarket were exactly that.

Whilst re-freezing previously frozen food is generally not advised, if it's fish that was previously frozen and is being sold as "fresh" fish in a shop, the fish will have been defrosted using a well-controlled method which allows it to be safely re-frozen. The thawing method leaves the previously forzen fish in the same condition as fresh fish.

[ConcinusMan]

Whilst re-freezing previously frozen food is generally not advised, if it's fish that was previously frozen and is being sold as "fresh" fish in a shop, the fish will have been defrosted using a well-controlled method which allows it to be safely re-frozen. The thawing method leaves the previously forzen fish in the same condition as fresh fish.

This is true. Most "fresh" fish was frozen during transport. However, I can get locally caught fresh steelhead and salmon in the Northwest. It was merely put on ice before reaching market. It's so loaded with mercury and PCB's (all WC salmon and steelhead is, with Alaskan salmon being the exception) I wouldn't use it anyway. That brings up a point about catching it yourself. Doesn't mean it isn't loaded with contaminants. Most WC fish is these days. Farmed fish is significantly lower in those contaminants. (PCB's, mercury) Tilapia is the cleanest as far as that goes, since tilapia eat only plant matter.