Post-Release Mortality of Greater Amberjack in the Northern Gulf of Mexico

The sustainability of marine fish populations depends on the accuracy of their stock assessments. The Gulf of Mexico (GOM) fishery for Greater Amberjack (Seriola dumerili) (GAJ) is primarily composed of discards, making up 75% of the total recreational catch. The mortality rate from released GAJ remains a deficiency in its stock assessment and needs to be investigated. To address this, a combination of multimode acoustic (n=36) and pop-up archival satellite transmitting tags (PSAT) (n=5) were used to monitor the fine-scale movement of the fish to determine survival post-release. Two acoustic arrays were deployed (n=30 days), each containing four acoustic hydrophones. PSAT tags reported to the ARGOS system after detachment from the fish. Survival statuses of released fish were determined from time series depth profiles recorded by the acoustic and PSAT tags. Five fish emigrated from the array within < 3 hrs and were thus not included in the long-term (72 hour) post-release mortality estimates. Based on 26 surviving, 4 moribund, and one fish unknown from irregularity of detections, we calculate a post-release mortality rate ranging from 12.9-16.12%. Our findings demonstrate that post-release mortality for GAJ in the GOM recreational fishery may be lower than estimated in the current SEDAR assessment.