From my own experience, scuds do not survive in any numbers when fish are present. I know that sounds funny but they are not real good at avoiding predation (slow swimmers)and rely on the cover provided by bushy pond vegitation.Sorry, I don't recall what Bill Cody identified as good pond plants for this purpose. I have transplanted many G. Lacustris to my pond while I still had trout, and within only a week they were gone, even with good cover. Since my pond is now fishless, the scuds are thick.
I have also noted the same thing at local lakes and ponds, lots of scuds means low fish numbers.
