Its was really interesting for me to learn that you need a CA fishing license in order to legally harvest sea vegetables as a recreational harvester! I checked the California Deparment of Fish and Game and it looks like someone would specifically need to get an Aquaculture Registration. Good to know... and especially good to know about the kind that turns your teeth green!DIY kelp harvesting
Those interested in harvesting sea vegetables on their own may do so with nothing but a California fishing license and a very minimum of specialized equipment. The leafy ends of most algae and kelp are quite tender and make for the best eating; snip off the tips and leave the rest of the plant. Remember that state law forbids taking more than 10 wet pounds of seaweed per day per person.
As a general rule of thumb, most seaweeds are safe to eat. One variety, though, which resembles a feather boa, gives off a sulfury aroma, and when sun-dried, baked and eaten, it will fill your mouth with a thick, unpleasant burning paste that turns your teeth green. (Of course I've done it myself, and for days I dared not smile.)