There is no such dichotomy as 'human rights' versus 'property rights. ' No human rights can exist without property rights.
Now when Nile perch was introduced [into Lake Victoria], I don't think enough research was done; maybe it was done, maybe it was not. But Nile perch is a huge fish. So it ate all the little fish, and it grew into a monster which the local people could not fish with their little boats and their little nets.