Bomb Radiocarbon Age Validation of Warsaw Grouper and Snowy Grouper

Abstract

Current stock assessments for both the Warsaw Grouper Hyporthodus nigritus and the Snowy Grouper H. niveatus are based on age‐structured population models determined using traditional otolith‐based aging techniques. However, recent studies using bomb radiocarbon validation have shown that many deepwater fishes live much longer than previously estimated when relying on conventional age determination methods. In this study, we conducted bomb radiocarbon age validations of Warsaw Grouper and Snowy Grouper from the Gulf of Mexico. Radiocarbon age validation supported annual growth increment formation for all Warsaw Grouper size classes and medium‐sized Snowy Grouper. Conversely, ages of larger, older Snowy Grouper were greatly underestimated due to difficulty in discriminating annuli. This bomb radiocarbon analysis validates a minimum 56‐year longevity for both Warsaw Grouper and Snowy Grouper, increasing the currently published longevities of 41 and 54 years, respectively.