as for futility, the Australian government has not only introduced compulsory kill legislation in some territories, but is looking at introducing a carp specific herpes virus to achieve their objectives and i understand this option has already been discussed in Spain...
I have been following the "Carp" issue in Australia for a while as I have a good friend who has just moved from Melbourne, where he was catching some beautiful carp, to Sydney, where he is struggling to get past huge eels to find a carp or three. He is fishing a city lake that I fished way back in the 80's and its great to follow his exploits online.
I spoke to him about the issues of "eradication" over there and he cannot understand it. He is fishing some of the clearest, yet weediest lakes I have ever seen, yet is being told the carp have to go because they muddy water ways and root up all the vegetation. He has been told that the eradication programme wont affect him in Sydney, but this virus is very easy to transfer on wet nets. Its a time bomb really, and I believe, completely irresponsible. The ornamental fish trade and keepers of Koi are in danger of losing everything.
It is strange that the only place carp apparently do "destruction" is Australia, New Zealand and some parts of America. Meanwhile, across the globe, and especially in Europe, we have never seen evidence of this.
The US have done similar eradications and ended up with dead waterways thanks to rotting fish stinking the place out. Even "natural" fish were wiped out because of what was effectively mass pollution. Now, after years of calling Carp trash fish, there is a sudden and fast growing band of carp fly fishers and waters that were once branded as "unfishable" have suddenly become carp meccas, with 20-30lb being sight fished in clear, shallow water.
There was a company in the UK that were trying to ship big Australian carp to the UK because the KHV virus was not in Oz, and therefore stock health could be guaranteed. I am not sure whatever happened to the idea.