1.  Load 10-ga. magnum with plenty of shot.  Steel will do in a pinch.  Perhaps 00 buckshot
2.  Head to safe range.
3.  Be careful that nothing is in the way between you or the target
4.  In line with #3, make sure the area behind the target is "safe" as well
5.  Have designated clear zones of fire
6.  Commence firing upon target.  
7.  Repeat #6 as necessary until Cormorant population reaches more reasonable levels.

Just kidding, of course    ;D ;)