Fish rescue?
I helped with a fish rescue a few years back. A dam failed on a small lake leaving thousands of fish stranded in low lying pockets that didnt drain. They would have died in a few hours if they werent moved to the small stream that continued to run through what was left of the lake. It was pretty interesting actually. I was quite surprised by the size of some of the bass, catfish, and American Eels. Even a few big trout. They made their way to a bigger lake downstream minus a few taken by osprey and herons.
Gill to Gill?