Winter springs do feed on sand shrimp,sand lance and prawns at times. Quite often you will notice there is scraping on their gill plates when caught. This comes from racing along a sandy or muddy bottom on their sides and catching sand shrimp. We have many bottom areas like this in the North Georgia Strait area and I have caught winters with shrimp in them. I am sure that they eat prawns too as I have seen parts in their digestive system. It may be something that they take on occasionas a taste, same way they will occassionally strike bait.
I use tiger prawn hootchies with great success over the winter and spring.
In one area with a flat sandy bottom right now we fish right on the bottom with the spin of the flasher and the cannonballs occasionally bouncing.
I also found the following information
Looked up this article from a Whatcom Salmon Recovery and also noticed when doing a search there are places that sell ghost (sand) shrimp to use as bait. So they must work.
There were some sites that showed how to rig them.
January 2005
Q. What do salmon eat?
A. What a salmon eats depends on age, species, and location. When salmon are young and still in freshwater they eat tiny zooplankton and adult invertebrates. However, this varies among species. For instance, young coho salmon typically feed during the day and prefer aquatic insects at the surface of a stream, such as, mayflies, caddis flies, and stoneflies. The young chinook salmon prefers plankton off the river floor, as well as, terrestrial insects and small crustaceans. Another food source for a young salmon is found on overhanging riparian plants. Larvae and insects feeding on this vegetation often fall into the stream adding to a salmon’s diet.
As a salmon matures and eventually leaves the freshwater for the ocean, their diet may change. While chum and sockeye salmon prefer to continue eating zooplankton and occasionally other small adult fish, other species begin to eat larger fish and aquatic insects. This includes shrimp, surf smelt, sand lance, crab, herring, amphipods, and krill. When a salmon returns to freshwater to spawn, feeding efforts virtually stop to conserve energy for the journey upstream, producing eggs, and digging a nest (redd).