Last I checked, cormorants were migratory birds, protected by numerous laws. Depredation permits could very well be available for them, however. Yes, they eat fish, and in some areas, do contribute significantly to mortality of fish. However, blaming them for the decline of a fishery is rather narrow. Seldom is there ONE factor responsible for declines in populations of a species. In most cases, it is a combination of a lot of things, some of which have been listed above.

Shoot one of these in my presence, and you WILL be hearing from fish and game.

I once floated the Green in Utah with a guide. The first time we saw some mergansers, he got angry, and then told us a story about how a bunch of the river guides got together every winter and had merganser drives in the canyon. A bunch of boats would float down the canyon, herding the birds out in front of them, and more folks would be down at the takeout, and shoot them as they went by. Basically legal, since mergansers are ducks and can be hunted. (provided they are eaten, which I hear is not common). The guide was proud of all the ducks they slaughtered every winter.

My brother-in-law looked at me at the end of the story, and I at him, and neither of us said anything for a minute.

The guide, to fill the awkward silence, looked up at me and asked "So, what do you do for a living?"

"I'm a wildlife biologist" I replied.