My thoughts:
I think in the fisheries management scheme, punch cards were used for both convservation and data collection in the early days of wild fish retention, and later, when fisheries were composed of mixed hatchery/wild stocks. Now with wild fish retention regulated byitself (5 fish per year; selected streams), the 30 fish limit would seem redundant, assuming the goal of removing all hatchery fish before they spawn in rivers.
However, here's another function of punchcards--spreading out the fishing opportunity. The old adage is true that 80 percent of the fish are caught by 20 percent of the anglers. This is probably true for most large rec fisheries just because you have your professionals like Bob, avid folks like me and many on this board, and the occassionals. My concern is this: would eliminating a 30 fish limit be taking away fishing opportunity? Would it skew catch rates further, say 95 percent of fish being caught by 5 percent of the anglers.
An example--summer running on the Sky. By most accounts, it was a reasonable sized run and fishing was fantastic in June thru early-July, particularly in the lower river. But come mid-July thru now, fishing was inconsistent to skimpy up high between Rieter and the upper South Fork. Some believe the large number of sleds and their abilities to catch lots of fish during a high water spring contributed to fewer numbers of fish in the upper watershed late in the season. Whether this is true or not, I don't know--no data like these have been collected. Another possibility is that the south fork run spread out in the upper river more than is typical because of the relatively high water present when they were trucked over Sunset Falls. But I personally know some sled guys that landed enough fish to claim a percentage of the run by themselves during the early season. This isn't a criticism of sleds, but an example of how unpredictable environmental variables can affect fish catch. This years high water made for some awesome fishing conditions early in the season on the Sky.
I know people are fond of voting their hearts and at first glance no punch cards sounds like more hatchery fish to bonk. But will it actually mean this over the course of a season? For winter steelheading, maybe. The winter brats run hard and fast and there aren't enough days for lower river fisheries to cause significant interceptions. But for summer-running, it really is nice to have productive seasons both early in the lower river and late in the upper river spanning a total of 5-6 mo. Rather than a 2 mo fishery during spring runoff and a scratch fest during the late summer and fall. I think most of us agree that maximizing fishing opportunity is a worthwhile goal, defined as fishing days as well as number of fish. If either of these goals is affected by the elimination of an annual limit, then as a management tool, it has some purpose.
One more variable to throw into the mix is the oft mentioned funding. To cite my home river again, over the past 10 years, summer-run collections at the Rieter Hatchery have gone from over 700 adults to just 350-400 because of decreased funding. Assuming similar smolt to adult survival, this is half as many fish to bonk. Last year, the North Fork Stilly didn't have much of a 2-salt run to speak of because of a funding hole that caused a one year skip in plantings.
During the early to mid 90s, this issue was moot--there were fish a plenty for everyone. But in the last half decade, the numbers of hatchery fish have not been as consistent. In these uncertain budgetary times, and always unpredictable environmental conditions, shouldn't management strategies seek to spread out catch over entire seasons rather than provide incentives to catch all the fish at once? This would seem prudent during low number years when meeting hatchery escapement goals are at issue. With no annual limit, this may be a possibility during some years, depending upon water conditions. And dependent upon conditions, the total size of the hatchery run, and the number of anglers, no annual limit may not mean more fish for all.