Adding salt to the transport water reduces the mineral difference between the water and fish blood which lessens the effects caused by this osmotic imbalance. Salt is added to make solutions of .05 Transport truck used to load live catfish. This is equivalent to 0.4 to 8 pounds of salt per 100 gallons of water. Use the lower rates on freshwater fish. Some species are very excitable and sensitive to handling and hauling stress.
Anesthetics are useful for sedating such fish, and to reduce the metabolic activity.
This means less oxygen consumption and less carbon dioxide and ammonia buildup. Also, energy is conserved which is available for maintaining ion balance. Fish can be over-anesthetized and die. Broodfish and species like redfish, largemouth bass, and hybrid striped bass respond well to anesthetics. A popular anesthetic is MS-222.