In choppy surf off of La Jolla, fisherman Shane Volberding fought to land a yellowtail, a silver and gold fish prized in the sushi seafood trade. Gulls wheeled above the water as the fish dove and darted against him, dragging the line. One crank at a time, Volberding reeled it in, jabbed it with a gaffe and then hoisted it on deck. As he grappled with the thrashing fish, his deckhand Destiny Louise Silva hauled in another yellowtail and dunked it in a bucket, tail up. The swift, back-to-back