Sampling has been simplified in the past couple of years. No longer is fin clipping required to identify fish; rather a small abrasive pad wiped across the tarpon's cheek, then dropped into a bottle of preservative, provides a permanent record of that fish's DNA. The fish can remain in the water for sampling and one person can perform the necessary steps, unassisted.
Each sample identifies a tarpon's genetic "fingerprint," providing a unique tag for that particular fish. Conventional tags may break or dislodge, but because a genetic code never changes, DNA samples accurately identify fish over the course of its life. Researchers compare new tarpon DNA samples with cataloged samples to determine if that fish was caught and sampled previously.