Could some guilds get dry fishing skill that could preserver our precious
fishes?
Would that not be pickeling?
I will consider pickling fish. In the meantime, I suggest you cook your fish
over a campfire.
Seriously, without any cooking skills at all, you can roast any meat/fish from
the hunting/fishing skills in any campfire to preserve it forever. You can
also cook some vegetables. It improves their food value and, in the case of
fish/meat, stops them from rotting.