Tennessee fisheries biologists decided to change their approach, stocking larger fingerlings ahead of the native bass spawn for competitive advantage. Five years later, in 2010, the results were remarkably different, with more than 30 percent of sample bass showing the Florida gene. The next year, the size and number of big bass being caught started to explode. By 2013, when 45 tournament fish weighing more than 8 pounds each were tested, every one of them carried the mark. But none were pure Florida bass.