Well I've worked in the hatchery system (DFO) for 20+ years now and I can say what we do but this might be slightly different than what the small Public Volunteer Program projects do. All coho smolts are marked from the major facilities UNLESS there is a conservation reason for not doing it, such as wanting the fish to help the native stock rebuild without being subject to a kill fishery. An example of this is on the Squamish system where the Squamish and Ashlu stocks are not marked but the rest of the hatchery stocks are. The marked fish are subject to a kill but not the unmarked hatchery fish. All of the marking is covered off under "A" based funding and there are no volunteers used. Chinook, chum, pink and sockeye are either not marked or just a per centage for assesment reasons. All steelhead smolts are marked. All of the fish are not marked for a simple reason - money and time constraints. It cost about 6 cents per fish (labour costs). Not alot but if you add up all of the hundreds of millions of fish released from SEP facilities, it's a huge amount of money. Money that no one seems to have. It is also not feasabile to mark 50 million chum as they come out of a spawning channel over a 1 month period. You just could'nt handle that many fish in such a short time. As far as survivals go, 96% would be nice but that dose'nt happen all of the time. Anything over 85 - 90% is accepetable but some groups get in the high 90's and others get in the low 60% range. There are lots of factors why that happens. Survival rates in the river are know where near 60%. A spawning channel may get that type of survival or the outlet of a large lake might get 40% but generally it's much lower. There is lots of evidence of survivals around 10% or less with survivals going down to 1% following a large flood (2003). It all depends on what type of habitat the fish spawns in, chinook / pinks in the mainriver will experience worse survival that chums in a upwelling gravel side channel .