Laser ablation AMS reveals complete bomb 14C signal in an otolith with confirmation of 60-year longevity for red snapper (Lutjanus campechanus)

Abstract: The use of bomb produced 14C to make valid estimates of age for various marine organisms has been in use for 25 years, but fish ages that lead to birth years earlier than the 14C rise period lose their time specificity. As a result, bomb 14C dating is limited to a minimum age from the last year of pre-bomb levels because the change in 14C through time is negligible for decades prior to ~1958. The longevity of red snapper (Lutjanus campechanus) in the Gulf of Mexico remains unresolved despite various forms of support for ages near 50 to 60 years. While the age and growth of red snapper was verified or validated to a limited extent, some skepticism remains about longevity estimates that exceed 30 years. In this study, red snapper otoliths were analyzed for 14C using a novel LA-AMS technique to provide a continuous record of 14C uptake. This approach provided a basis for age validation that extends beyond the normal limits of bomb 14C dating with confirmation of a 60-year longevity for red snapper in the Gulf of Mexico.