The Japanese wash all their fish for Sushi in a saltwater brine. A very old practice. Since I dry age my Crappie fillets to substantially reduce the water content in the fillets for a firmer, crisper, coating that stays on the fish I don't brine Crappie. Brines create a "Reverse Osmosis" condition helping the fillet hold more that water I'm trying to remove. Black fish (Tripletail), Lemon fish (Cobia), Redfish, etc. all get a brine bath. It is a good practice in my opinion for those heavier flaked fish.