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Discard mortality rates of red snapper after barotrauma and hook trauma: Insights from using acoustic telemetry in the U.S. South Atlantic

Published Article

North Carolina

Publication date: April 29, 2025

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Discard mortality is a major concern for red snapper fisheries, where released fish often outnumber harvested ones. Using acoustic telemetry at a 38‑m natural reef off North Carolina, researchers tracked jaw‑hooked and deep‑hooked fish returned to depth with recompression devices. Movement profiles revealed stark differences: jaw‑hooked fish had low discard mortality (6.3%), while deep‑hooked fish showed extremely high mortality (87.5%), among the highest recorded for this condition. These results provide critical estimates for U.S. South Atlantic fisheries and demonstrate that deeply hooked red snapper are unlikely to survive release, underscoring the need for improved handling practices and management strategies.

Subject Tags

  • Fisheries
  • Wildlife

Abstract

Objective

We studied discard mortality of red snapper Lutjanus campechanus, a reef species that experiences barotrauma and hook trauma in its U.S. hook-and-line fisheries. Annual numbers of discarded Red Snapper far exceed those harvested in federal fisheries management regions, a phenomenon that emphasizes the importance of quantifying discard fates.

Methods

To estimate discard mortality, three-dimensional movement data were collected using acoustic telemetry tags and a 3-km2 array of receivers deployed in 2019 and 2023 at a natural reef area (38 m deep) off North Carolina. Release treatments were jaw-hooked or deep-hooked fish; all fish were returned to depth with a recompression device. We assigned a fate for each released Red Snapper based on movement profiles revealed by the acoustic detection data; fates included discard mortality, lost tag, emigrated/harvested or alive within the array when the receivers were retrieved. A Kaplan–Meier survivorship analysis was used to estimate the rates of discard survival for each release treatment.

Results

Mean proportional rates of discard mortality (1 − survival) were 0.063 (95% CI = 0.001–0.122) for jaw-hooked recompressed fish and 0.875 (0.543–0.966) for deep-hooked recompressed fish.

Conclusions

Our study provides estimates of discard mortality for red snapper at a depth where the species is often captured in U.S. South Atlantic commercial and recreational fisheries. Our estimate of discard mortality for deep-hooked red snapper is among the highest published rates for fish in this release condition and demonstrates that deeply hooked red snapper will likely die.

Citation

Rudershausen, P. J., Runde, B. J., Tharp, R. M., Merrell, J. H., Bacheler, N. M., Patterson III, W. F., & Buckel, J. A. (2025). Discard mortality rates of Red Snapper after barotrauma and hook trauma: Insights from using acoustic telemetry in the US South Atlantic. North American Journal of Fisheries Management, 45(2), 270-282. https://doi.org/10.1093/najfmt/vqaf012

TNC Authors