I eat makerel, bass, and sea trout amd a few others that I catch myself. I dont bother freezing it as it sofens the tecture! I just make sure the fish is healthy and from a safe area!

I used to be a longline tuna & swordfish boat crew in the Caribbean & South America. You would not believe the care that goes into their preparation from the moment it is landed on the boat. If you've seen 'The Perfect Storm' you'll have a very rough idea of what goes on.

For the swordfish, meat conservation is pretty easy. Once the fish is gaffed aboard it is killed with a swift blow to the head while in a cradle, gutted, finned and beheaded. The carcass is put in vat of really ice cold seawater held at a temp that will drop the core heat right down. It is then packed into the hold covered in saltwater ice, it will last down there with no loss of quality or flavour for ages.

Tuna is whole different ballgame. As we were fishing for the Sushi market, we targeted Yellowfin and Big-Eye tuna from about 80lb to around 250 and above for prime meat. Bluefin is now so rare we tried not to catch them if possible but they can grow to be huge.

Once the tuna is gaffed aboard and despatched, it is beheaded and then a stainless steel rod is pushed up the spinal column so twitching will not ruin the muscle, all this must done in seconds. Gutted and finned it is then packed in freshwater ice as saltwater ice is too cold and will burn the flesh (it goes a naff grey colour and loses firmness). To drop the core temp the shaved ice is packed into the belly cavity and the fish covered. Every 4 to 6 hours the the cavity ice is changed until it stops melting. Saltwater ice is easy to make onboard but freshwater ice is a lot more complex and expensive. Can you image all the man-hours this involves?

When back in port, after 10 days to 3 weeks fishing, eash fish is removed, weighed and graded. The grade will give the price for each fish, an AA will have a beautiful red flesh the colour of a ripe cherry tomato and real firmness. These are the ones only taken by the finest restaurants. We got around $5 a pound for these rare beauts. As the grade goes down so does the price.

Each fish is then packed in a polystyrene coffin with fresh ice, taped up and given its own mini-passport for shipping. They are then flown to Miami or New York for sale there or onto Japan or Europe. This is top dollar fish that needs no freezing or mucking about with.

Unfortunately most of the tuna we get in Europe, except some Med fisheries, are caught with seine nets off West Africa. This filthy fishery kills the young, dolphins and turtles; none of the above described care goes into looking after the fish so that worms, bacteria and parasites can be present.
Ask your fish supplier just where he gets his tuna. Please be careful.

Will Ceviche kill said bacteria?

Excellent post! I am facinated about fish and fisheries! what is it you do now?