...Wait, the answer is hatcheries. WDF did have, at one time, a Razor Clam hatchery. Get Brian Blake to sponsor a bill that would put one on every beach and we can fish all year. 'Cept maybe for that Domoic Acid thingy.
RC bios have told me, though, that much of or RC production of young comes from a relatively small area and turrets spread them up and down the coastline.
FYI The hatchery was at the Willapa Bay Shellfish Lab (now called Willapa Bay Field Station) in Nahcotta. It started out as a pilot project (mid 1980's ) just to see if they could be reared in a hatchery environment. Once they found they could it morphed into an enhancement project. Biggest problem was they could never prove any of the clams they planted survived to make a contribution to the fishery. They tried various ways to mark with dyes, tetracycline, etc but didn't find anything effective.
At that same time they had a subtidal enhancement program that ran out of Montesano. They would collect clams just offshore in 20' of water or so. They towed a small sled with jets that would liquify the sand just enough to collect set clams ( 3/4 inch or smaller). They would get maybe 4-5 5 gallon buckets full of set clams a day and would then relay them for transplant to the research areas that were set up. Once again they couldn't prove it made any difference and both programs were defunded in 1988 or 1989.