There are continuing reports of Herring Worm Anisakis simplex infection in Japan, also Scandinavia. Not in the USA only because it is not a reportable required disease, though cases are known to occur.
FDA requirements for all seafood should be cooked at a temperature of at least 63° C, and fish should be stored at a maximum temperature of -20°C = -4ºF for 7 days or -35°C = -31ºF for 15 hours for safe consumption.
Most household freezers maintain temperatures from −23 to −18 °C (−9 to 0 °F), although some freezer-only units can achieve −34 °C (−29 °F).
I recall that I have only seen tuna retailed frozen.
Most fish contain parasites that for safe eating must be killed by freezing or cooking. This is of particular concern when consuming fish that is served raw or cooked well below the safe value e.g. Tuna. This is of particular concern for anyone with a compromised immune system. Another reason for freezing is that fresh fish does not do well as it ages. Even with overnight shipping the time from catch to table can be too long for optimum quality. I grew up catching salmon and having it for dinner and you can really tell how much better really fresh fish is. Here is a article on fish https://www.fda.gov/media/80777/download
I don’t think stores cater to those customers that buy for future use. I would also guess it is a ploy to make people believe it is fresh even though it is marked. I would ask the meat manager if you can arrange to get it still frozen.
Yes, I have considered that it is a marketing ploy. “Oh no, my fresh Escolar has gone bad already, I must buy more.”
I was traveling the Canadian border regions of - I think - New York state, when I noticed a seafood restaurant advertising Escolar. I had a small serving with no Ill effects.
Escolar is notorious as a source of escombrid gempylotoxism or gempylid fish poisoning.
I think something to keep in mind here is that a very large number of our populace really do not know anything about where our food comes from or how it is processed. Eg., If you buy frozen cod, frozen wild atlantic salmon, etc, you are usually getting a fish that is caught on a factory fishing vessel, processed and flash frozen for packaging on shore. In some cases the process is more involved. Even when seafood is just refrigerated, it is typically processed very quickly on shore and once again, flash frozen. Doing this gives you the best quality product, provided you know that you should be shopping in the frozen aisle and not in the fish set. The fish set is there, as suggested previously, for folks that are buying a product they do not intend to refreeze. On that note; You can ask them to bring you frozen fish, scallops, lobster, etc. I’ve never been told No when I asked if they could bring me a frozen item from the back as I need to hold it in the freezer for a bit myself.
During the thawing process, the surfaces of large frozen products will reach higher temperatures sooner and will be exposed to temperatures that can promote microbial growth for a longer time than the interior parts of the product.
One is not supposed to thaw at room temperature hypothetically, but at 40ºF still below the danger zone.
I don’t know how large is your ‘large’ but it has become my standard practice to cook frozen, typically an hour or two additional to reach desired core temperature.
See Douglas Baldwin’s A Practical Guide to Sous Vide Cooking, Table 2.3: Approximate heating times for frozen meat to 1°F (0.5°C) less than the water bath’s temperature.