My understanding is those fish are classified as an "extreme conservation concern"...although I have heard rumors to the effect of them considering lifting the "release all fish, hatchery and wild" edict that was put in place...
It is a very short river, 5 km from the hatchery to the ocean, so it doesn't take long for them to get to the top...
Right now I would bet fishing from just above the highway down to the railway bridge on the high tide could be productive, but you would have to have the benefit of some flow through there, and I'm not sure of levels right now...It's good river to explore, and you can cover several sections of it in one day.
It's definitely worth a shot...head up to the hatchery and observe the tailout of the cable pool, if they've arrived in any decent numbers, you'll see some holding in that tailout...If they're there, I would leave those fish be, and work the water downstream from there. Fishing cable pool for them is not very responsible as landing them there does not have the fish's best interests in mind, besides you have to release them all anyways...Fish the pocket water below cable, dog leg, and then hit mid canyon...but check your tides...there can be decent fishing in the lower river if you time it right.
Remember, you have to release not only wild fish on the capilano, but also the hatchery fish!!! Don't forget that when you see that adipose fin missing...
Good luck,
rib