The Feasibility of Bomb Radiocarbon Analysis to Support an Age-at-length Relationship for Red Abalone, Haliotis rufescens Swainson in Northern California

Abstract

Analysis of bomb generated radiocarbon (14C) changes in a red abalone, Haliotis rufescens Swainson shell was used to evaluate age-at-length relationships derived from data from a previous multiyear, multisite tag-recapture study. Shell carbonate was extracted from four successive growth trajectory locations in a single shell with a maximum shell length of 251 mm. Extraction locations were based on Von Bertalanffy growth function (VBGF) predictions and chosen to span the initial rise of the 14C-bomb pulse that is known to have occurred in surface ocean waters during 1958 ±1 y in the northeast Pacific. The close temporal correspondence of the red abalone sample series to regional Δ14C records demonstrated the utility of the technique for validating age-at-length relationships for the red abalone. The findings provided support for a mean VBGF derived age of 32 y (range 30–33 y) for the specimen; however, the analysis of 14C data indicated that the specimen could be older.