You can just walk on to some of the bait barges in the harbor. I think at the very least MDR and Channel Islands harbors have bait docks you can just walk on to and pick up some bait.
LOL Jon, that's a bit of a drive for him...the closest that I know of for him to even approach is probably in Newport harbor. He can drop a longboard (you can get those floating bait buckets) in the water near the harbor entrance and paddle over (or a kayak or even a float tube). If he's lucky enough he can call them and see if they'll motor over to the rocks with some bait...I don't believe John is there anymore, but if they're manning the bait receivers, they start early, and leave whenever business slows down...might be as early as 10am they shut down.
Nacho over by the LB breakwater lives on the barge with his 1 1/2 dogs and usually a cousin in the busy season...but that's a mile out.
Heck, now that I think of it in San Diego you have to have a boat to get bait and if you're in the lineup late, you wait...just don't be behind more than one party boat...