We are in the middle (I hope) of a major drought in Southern CA, and I believe that includes San Diego and Imperial counties. When there is no spring rain at the appropriate time, California quail don't reproduce that year. In several years like that, there will be a "die off."
One good source of California hunting info is the "Hunting and Fishing" forum on the website
www.calguns.net I'd ask your question there and also do a thread search for "quail" and "San Diego" and "Imperial." But I think you'll find quail very scarce in that area, except in the (not huntable) suburbs where they have artificial water sources.
Saltwater sport fishing in that area IS excellent. The only thing wrong with rockfish charters is that the fish are caught on the bottom and you basically just crank them up onto the boat. But you do get a SACK of delicious fish out of the deal and almost never come home without a feed.
BUT (the BIG butt), yellowtail (like amberjack back East) are both champion fighters and about the best fish to eat, bar none. I just had some filets.