The survival rate of steelhead spawning in the wild is minimal; fish being held in a dark compartment for a few months and treated with formalin to combat fungus and bacterial diseases no doubt lowers this survival even further and... air spawning steelhead requires a docile fish and if the fish are not sedated (and if they are to be released they cannot be sedated with anaesthetics) are very difficult to handle, hence the gloves.
IMO, air spawning steelhead is entirely for optics and a waste time and effort. Autopsies of air spawned Chilliwack River steelhead morts invariably had 5-600 eggs remaining in the body cavity; multiply this by the number of females used and the benefit of releasing these fish is most often negated.
Time for the Province to get it's collective head around this misdirected procedure and follow standard hatchery procedures for salmonids for optimum production and that means killing the broodstock when sexually mature.
Feeding them optimum rations and proper water temperatures when being reared is helpful also