What's the best method? Let us say you are out on a wild camping and fishing trip and you catch a decent fish at 10.00am but you don't want to eat it til the evening - what would you do? For this scenario we are also imagining that the fisherperson concerned is not so expert that they can bank on catching another decent fish or two late afternoon. The decent fish caught in the morning might well be the best (only) fish you land all day.....
Sorry, should have said it was more for on the hoof I was thinking of. Would you take the bass bag out and leave it submereged in water at your next location etc?
If this all sounds a bit daft, it probably is - I almost invariably put my fish back, but am planning on a trip where I might be away for a near a week and have to eat a few more.
Eat it for lunch instead of dinner :)
Clean it, de-head it, wash it and wrap it in a wet towel and put it in a plastic bag in your rucksack. Keep the rucksack turned face down if you leave it to go fishing as the padded back will stop the inside heating up too much and in the shade if you can. At dinner time wash the plastic bag, towel and fish in the nearest water, make sure you get the towel and bag clean as it will stink to high heaven otherwise. Any fish you catch should be fine at the end of the day.
Poly bags are fine as long as you don't put the fish in them without covering them first, hence the wet towel. I have been doing it that way for years. I read some where that there can be parasitic worms in the gut or liver that migrate into the flesh when the fish is dead and that the gastric juices keep working and can puncture the stomache and the contents contaminate the flesh. Can't say I've ever had that problem as I gut the fish the same day they are caugtht.