There's no argument that breeding Cormorant numbers in Britain DID rise in the past but, as has been pointed out, numbers are no longer growing (let alone exponentially, which has a very precise mathematical meaning), but are falling. The report I showed you indicates a 7% fall since the year 2000 - this is determined from very intensive survey work covering the whole of Britain. If you want to refute this finding, let's see your evidence. Ditto evidence that Cormorants are having the impact that you describe on fish populations.
My blog: http://mazzaswildside.blogspot.co.uk/
My Flickr page: https://www.flickr.com/photos/124028194@N04/