It's all in the genes—including the tracking device

It's all in the genes—including the tracking device: "Parentage-based tagging (PBT) is an emerging genetic-based fish tagging method that involves genotyping hatchery broodstock. PBT is a passive non-invasive approach to stock identification because the parents, not the offspring, are genetically sampled at spawning, thereby "tagging" the offspring. This method provides the same information as traditional physical tags but also allows for collection of more detailed information that previously was impossible or impractical to gather using traditional tagging methods."