Is it outside? Sap from another tree? Maybe scale? I've done lots of chopping and such on my spruces the last few years and i never get sap on the needles.
Sometimes sap will bleed in tiny amounts from the trunk, but that's it.
I got leafs to form drops after I threw a pine into a wall.
With spruce, my guess is the same. The pressure from inside the plant (especially in spring) is enough for sap to seep out of every damaged crack you haven't noticed before. Animals/insects can cause cracks..
One other possibility is seen in some orchids and plants alike: it's so healthy that sugar storages are flowing over. There's no break on sugar production so vasicles just burst open and leak outwards. Like pumping a tire too full.
Another possibility is honey dew from aphids living in a tree nearby.
I'm fairly certain its not from any other plants, and I haven't seen any insects on it, I'm going to assume it has to do with the weather getting warmer here, possibly stocking up on its resin in the needles to prevent water loss, since a lot of native pines/firs do that here.
There also is no sap leaking from the trunk or any branches either, which is what seemed odd to me.
I wouldn't think too much light but i dunno about the heat there. Not really sure how you are growing them in zone 9 when they like cold winters. Zones 2-7, i'm no expert on pushing limits but can they handle the warm winters?