I have ALWAYS been of the opinion that rod licences should be issued only to people who have past a written test and an interview. I understand this happens in Germany. The licence would have their photograph on, and a centralised system would ensure that the licence could be taken away if transgressions have been proved. Like driving licences.
Then, assuming a fishery owner checks that visitors have a rod licence, he has some sort of insurance that their behaviour will be reasonable and that fish will be looked after.
Of course the licence would cost more than it does at the moment, but the harder it is to get a licence for anything the more people appreciate it when they have one.
I like that idea as well. But I would worry about it putting people off trying fishing for the first time if there were to many barriers to making your first cast?
It's not the fishing part that irks me, everybody has to start somewhere. Its the rubbish that a small number of people leave everywhere and the anti social behavior exhibited by a few others, unfortunately that's an issue with society that effects fishing as well.
As an earlier post pointed out, sometimes experienced anglers leave rubbish on the bank. So knowing how to fish isn't going to stop that problem.