What technique was combined with otolith analysis to reliably estimate the lifespan of long-lived GT specimens?

Answer

Bomb radiocarbon dating

Bomb radiocarbon dating, which measures the spike in atmospheric carbon-14 from 1950s and 60s nuclear testing, was used to validate the ages derived from otoliths.

What technique was combined with otolith analysis to reliably estimate the lifespan of long-lived GT specimens?
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