I really don't understand what you mean when you say "The same could be said about cormorants".... in the context of degrees of difficulty in controlling the numbers of these two completely different critter Joe.
Zander are fish, and to all intents and purposes, invisible most of the time. They live in amongst a mixed mass of other fish, with no means of separating them...and no means of controlling the numbers without killing all the other fish as well. In other words, a HUGELY difficult task.
Cormorants on the other hand are birds....they spend a great deal of their time VERY visible indeed....in fact they spend a fair bit of time sitting motionless in trees resting. When drying their wings for hours on end, they kinda look like they are holding their hands up in surrender
Even more conveniently, they tend to gather in large groups in their favourite (easily identified) trees at roosting time. Reducing their numbers is therefore a
relatively simple task. And who said anything about getting rid of them completely Joe? All that's needed is to reduce the numbers to a manageable, sustainable level....and keep it that way.
Lastly, you claim that nobody is prepared to have a sensible debate on the subject Joe
I must be missing something here, because I thought that was what we were having? I agreed with you previously that they are indeed a non indigenous species...so they shouldn't really be there. And yes, they MAY be part of the problem....in some areas.
However, zander still remain in
relatively localised areas (Although they are spreading year by year) There are still massive areas of our waterways where they are not present at all....so they can't really be 'A part of the problem' where they don't exist, can they? The problem still exists where zander are not present Joe. Cormorants on the other hand are pretty well everywhere, they even frequently commute many miles to work and back...just keep your eye on the sky while you are fishing to prove that
So....they CAN fairly be classed as 'Part of the problem' just about anywhere. Do you see what I mean Joe?
Cheers, Dave.