Scientists researching the sustainability and health of tuna fisheries in the Pacific recently recaptured a bigeye tuna off the coast of Fiji–a fish they originally tagged 13 years ago.

According to the Fish Information and Services‘ website, rediscovering a fish after such a long time is a first for the team of researchers. Spokesman Bruno Leroy says the fish was originally one of thousands fitted with a numbered plastic tag and released back into the ocean. Relocating tagged fish at a later date is critical for estimating the status of tuna movements, stocks, and the impact of fishing.

“This fish is a great find,” he says. “Recovering the tags is crucial to the success of our programme because they provide information on the growth, movements, natural mortality and fishing mortality of tuna, and help us estimate the status of tuna stocks and the impact of fishing. And he added: “The fish was an old fellow, at least 15 years old, and its recapture is of great value for us as an indication of the longevity of bigeye tuna.”