This sounds similar to the Great Hanoi Rat Massacre (https://en.m.wikipedia.org/wiki/Great_Hanoi_Rat_Massacre) where people got paid per tail but ended up breeding more rats to get more tails.

Bison take much longer to have a calf (9.5 months + 7-8 months of nursing) and typically only have one calf per go around. Carp, on the other hand, produce about two million eggs per year. It's much easier to depopulate bison than invasive carp.