In order to study fish, their behavior, and their traveling and migratory patterns, the National Oceanographics and Atmospheric Administration (NOAA) requests fishermen to tag a fish and return it to the sea. After a tag is placed, a fisherman sends the tag number to the NOAA Fisheries, along with the date, weight, length, and location. If the fish is located again, the fisherman reads the number and can call it in. In this way, scientists track migration patterns and make other important estimates on growth and reproduction of these species.
Al Anderson is one of the many fishermen that participated in the NOAA Fisheries Cooperative Tagging Program. He is a charter boat captain in Point Judith, Rhode Island. No other fisherman has tagged as many Bluefin tuna as Anderson. One of his first tags was on a 9-pound Bluefin tuna fish that he captured in 2004. He tagged it and released it. The fish was recently recaptured in the Mediterranean Sea, off the coast of Sardinia, 3,865 miles from where it was tagged and released.
The remarkable fact was that the fish now weighed 602 pounds. Anderson said, “This was the 13th bluefin tuna I caught, tagged and released. The tagging of fish caught by fishermen helps scientists determine their migratory pattern, define their populations and if possible, estimate their growth rates, population sizes and mortality rate.”
So the fish was recaptured 16 years after Anderson tagged it. This is only the second Bluefin tuna fish in the NOAA Program´s history that had been at liberty so long. The first one was captured last year after Anderson had tagged it in 1997. At that time it only weighed 14 pounds; when found it weighed more than 1,200 pounds.
The tags placed on the fish by the fishermen are a powerful tool to better study and understand these species. Derke Snodgrass, a biologist at NOAA says, "They're basically a flash drive that you attach to the fish." The flash drives record all types of information every ten seconds including water depth and temperature.