Norm, we had a dozen cormorants on our pond this last weekend and one osprey. While fishing Sunday I caught a 17" LMB that was missing scales on boths sides and she looked like a cormorant had tried to catch her. I suspect she was just a little bit too big for a cormorant but my best guesss is that a 15" LMB would be no problem for your average cormorant. \:\(