Most people might not realize this - but frozen fish is at least extremely useful and can be very convenient.
You may only have the tastes for certain species of fish and as they are not always around or available for purchase in 'fresh' form, buying frozen allows us to purchase these particular species at almost any time of the year.
The larger commercial freezers can hold fish as low as -22°F (-30°C) and this is what's known as cryogenic freezing that uses both liquid nitrogen and carbon dioxide.
This allows for much longer storage times as the breakdown process that naturally occurs and the potential growth of bad bacteria is delayed when frozen at these much lower temperatures and with this procedure.
It's much better to buy frozen fish in this form rather than buying or catching fresh fish and then freezing in your own home freezer for these longer periods of time.
Incorrect freezer storage is going to result in the fish proteins losing their natural structure and thus their ability to hold water or moisture. Once this fish is thawed out, the flesh actually drips excessively and can look quite dull and spongy.
Before you purchase frozen fish, you need to look for the following and then avoid:-
Fish Oils in respect to freezing: The oils in fish will soon become rancid if the storage temperature is too high or if the fish has insufficient protective packaging or if there isn't an ice glaze to prevent air from reaching the flesh. Smell will instantly give this away once thawed.
Freezer burn occurs during frozen storage if the temperature has fluctuated and there is air present within the wrapping of the fish. Essentially freezer burn is dehydration.