“We measured lifetime reproductive success of the first two generations of steelhead trout that were reared in captivity and bred in the wild after they were released. By reconstructing a three‐generation pedigree with microsatellite markers, we show that genetic effects of domestication reduce subsequent reproductive capabilities by 40% per captive‐reared generation when fish are moved to natural environments. These results suggest that even a few generations of domestication may have negative effects on natural reproduction in the wild and that the repeated use of captive‐reared parents to supplement wild populations should be carefully reconsidered.”   Hatchery Impact on Wild Fish via Native Fish Society  

Tweaking them, counting them, milking them, dumping them, tagging them, 'managing' them.

Weakening The Gene Pool