To be a bit more specific..... It's 22 inches minimum for a California Halibut, and I believe 26 or 28 inches for Pacific Halibut. If you are in Southern California, no worries... However, if you are in Northern California (I'm not), you have a chance at catching a Pacific Halibut, so it's essential to know the min. size for them.
Most probably. Don't know anyone who has ever caught a 'Pacific' Halibut there. They are easily identified though, as the Pacific Halibut is often darker, and 'diamond' shaped, vs the California Halibut that is somewhat elliptical. Hope this helps,