One way to look at the loss of fisheries due to river closures, etc, is to look at what is to be potentially gained (or, more appropriately, re-gained) with restored salmon stocks, more rivers open to salmon angling, and therefore more anglers is this example from NB:
2005 - year of DFO's study: about 20,000 licensed salmon anglers in NB.
2010 - year of Gardner-Pinfold study - 22,500 licensed salmon anglers in NB. (numbers up most likely due to better returns). This is about a 12% increase from 2005 which would explain, at least in part, the higher economic value in 2010 than in the 2005 DFO study.
1989 - the peak year for salmon licenses sold in NB which was about 36,100. Back then, the entire St. John River watershed and its tributaries were open for salmon angling, as were many, if not all, the Inner Bay of Fundy Rivers. Just on these numbers alone, getting back to 1989 numbers of anglers in NB would represent a 60% increase over 2010 numbers. That's a whole lot more angling activity, and therefore economic activity. Just a simplistic projection of the numbers would take the 2010 GDP of $55M for NB to nearly $90M in today's dollars. There would be some corresponding increase in the number of Full-Time Equivalent jobs as well. Of course this oversimplifies the reality, but it does speak to the potential of what we can gain - and I think this is what we need to focus on more than what we have lost - when we are all reaching out to our elected officials. It certainly enables us to really hammer the point home of the value of restoring salmon runs on the mighty SJR.
I have no doubt in my mind that the more rivers we have open to salmon angling, even if they are strictly limited to C&R only on rivers that are "under restoration", the more people we will have joining the ranks of the local angling and watershed groups and the whole cause gets stronger.