Having officiated at several matches on commercial fisheries I cannot see how anyone differentiates between the serated dorsal of a barbel and that of a carp. They both have them and small carp in particular are notorious for getting hung up in keepnets.
On the subject of retention I have only ever witnessed one barbel die in a retaining system and that was in a Queensford of all things. I've yet to see a barbel keel over in a properly staked out keepnet and if I'm being perfectly honest with you, a Queensford is merely a small keepnet with a zip along the top rather than an open end. Whether it is even legal to use one is debatable because it doesn't meet the criteria laid down for minimum keepnet lengths.
It is fashionable to afford barbel 'special' status when it is no more precious than any other. In my current blog:
http://www.bobrobertsonline.co.uk I broach this very subject.
Articficially reared barbel may yet be the saviours of angling, particularly on those river systems where natural recruitment is poor. But this comes at a price. Someone has to fund the breeding project and manage the surplus production in a way that is ecconomically sound and humane. Sales to commercial interests keep the price down and make the entire process viable.
The option is to slaughter the surplus fish stocks.
Which would you rather happen?
Without stillwater barbel the future for running water barbel is jeopardised. Without running water barbel what's left in our rivers? Where are the shoals of small chub and dace, of bream and roach. Those goliaths we catch today are not getting any younger and face increasing threats of predation.
Carp at the levels we see today are potentially unsustainable. They are not indigenous to the UK and the risk of currently known diseases and potentially ones we don't even know of yet could lead to a catastrophic collapse of our fish stocks. And then what do we have let?
Bio diversity is essential to future viability of fish stocks and for angling itself, be that in still or running water. To ring fence one species does no-one any favours.