Todd -
Your suggested ratio of 75 wild fish to 25 hatchery fish in April illustrates clearly one of the down sides of late timed wild brood stocks. If it is indeed as you suggest or even close to that ratio then on those years with poor wild runs (recent past?) and no fisheries in April there must be an awful lot of hatchery fish spwaning with wild fish. In your example it might be as much as 25% - clearly above the guidelines in the State's Wild Salmonid Policy (max. of 10% for similar stocks). I assumed (probably incorrectly that peak wild spawning in much of the system would be late April/early May -thus the ratio of hatchery to wild in mid-April would likely be that we would see on the spawning grounds.
On years of poor wild runs the managers face the dilemma of having excessive hatchery fish spawning or exposing the depressed wild fish to extra fishing impacts.
I can hear so of the earlier posters ready to argue that the hatchery fish from wild brood stock are as good as the wild fish. I don't believe so. There is a growing body of information that any offspring from fish that had spend an extend period of time in hatchery do not survival as well as naturally produced fish from wild fish. Perhaps a hypothetical example will illustrate why that might be. Let's compare the results of a pair of fish spawning in the wild and a pair used in a brood stock program. I will use a typical fecundity of 5,000 eggs per female.
The wild case - For a river being managed unde MSY and the escapement goal being met those 5,000 eggs would typcially produce about 30 smolts or with a 10% smolt to adult survival I would expect those two spawners to produce 3 returning adults - In this case the population could sustain a fishing impact of 33%. If the river was managed at carrying capacity then I would expect about 20 smolts and 2 adults - fishing impacts would have to be zero!
In the hatchery/wild brood stock those 5,000 eggs might produce 3,500 smolts and with a decent hatchery smolt to adult survival of 4% would produce 140 adults.
Please notice.
The eggs from naturally spawning fish had a freshwater mortality of more than 99%. That means that the resulting smolts were the fittest of the fittest. The parent female likely was more successful than most in picking a good redd site. The fry that survived had behaviors that were the very best at avoiding predators, feeding food, finding safe refuge from floods and droughts and were very luckily. When they return they will likely pass those behaviors on to their offspring.
Meanwhile that fish produced in the hatchery were not nearly as rigorously selected against (freshwater mortlatiy of 30%) and many of them will have behaviors that would not be as successful in the wild. Thus in the wild on the whole their offspring will be less fit than those from naturally produced parents.
It should also be noted that there were a heck of lot more adults produced in the hatchery program per pair of spawners. Hatcheries can be very good producing fish to catch but not very good at producing successful spawners.
All of the above once again shows how complex steelhead and steelhead management are.
Tight lines
Smalma