There is something that worked for a guy I knew in Texas that caught large hybrid stripers in his pond in warm water. They would fight so hard in the warm water they could go belly up and he claimed it worked. Not sure it would be practical for you but here goes:
He had a cooler of water with an oxygen diffuser in the bottom, which via an airline was connected to a oxygen flow meter, then regulator and then an oxygen tank. I use the same set up to move small amounts of fish I sell. It doesn't take much oxygen to saturate the water. I don't buy my tanks. I get them from a local welding supply store, and just bring them back when empty to get another one that is full.
Remember this is pure oxygen -- not just air.