First of all, it would be…

First of all, it would be imperative to produce good data that shows that Double-crested Cormorant populations are the cause of any decrease or fluctuation in commercial fish. Predator - prey interactions are seldom linear, and perhaps there is a positive to commercial fish from a predator such as the Double-crested Cormorant. In complex systems, this is a possibility. Either way, the data needs to be out there and clear, before one tries to solve a problem that may not be solvable by culling Double-crested Cormorants. Perhaps Double-crested Cormorant are a symptom rather than a cause of a problem in the Great Lakes ecosystem. If you cull cormorants, why not egrets, herons, Caspian Terns etc. Perhaps some of those have a greater effect on commercial fisheries? If it is merely the population number, it means that you are being simplistic in your understanding of what the dynamics are in the system, and you may be making the incorrect assumptions. I say no culling of cormorants, or other fish eating species, until you have clear, data from multiple studies that clearly show that the culling will have a positive effect on the prey species that you want to manage for.