Juvenile red snapper (Lutjanus campechanus) : stock discrimination in the Gulf of Mexico

Abstract

Juvenile red snapper Lutjanus campechanus from 2009-year class were sampled in three regions across the Gulf of Mexico; Western, Central and Eastern Gulf. Otolith elemental signatures of Ba were analysed through laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to determine whether Ba could be used as a reliable geographic marker across sub-populations in the Gulf of Mexico. Otolith age and growth also were analysed to determine differences between Gulf regions. Differences in otolith chemical signatures of Ba concentrations were distinguished across Gulf regions together with age and growth rates determined by birth date. Differences were observed within and across Gulf regions suggesting juvenile red snapper were spatially mixing between sub-stocks. Incorporation of Ba concentrations in otoliths displayed significant differences across GOM regions determining it was a reliable geographic marker. However, growth rates were consistent across GOM regions and standard length and age displayed no significant results. Therefore, stock discrimination based solely on age and length could not be established.

Date of Award	2017
Original language	English