Fish in the images above appear to be getting fungus growth from handling stress problems. I notice the infections on the sides of the fish that correspond to where they were probably hand gripped when removing the hooked fish. HOw big of a container was use to transport fish? and where were fish held and for how long before the trip to your pond?

There is nothing that you can do to help the first batch of fish except to learn from your first mistakes.
Just because a fish swims away does not mean it will be alive two weeks later.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management