Stocking sterile trout is the topic for Dr. Hal Schramm examines in this Thursday Throwback.Stocking sterile trout has become a tool for fisheries managers. Why you ask? To restore and maintain the population integrity of the given subspecies. Dr. Hal Schramm points out that fertile stocked fish create hybrids that proliferate and can effectively outnumber and even eliminate the native species. That cross-breeding can complicate matters for both species involved, and led to the studies quoted here.