Co-Producing a Shared Characterization of Depredation in the Gulf of Mexico Reef Fish Fishery: Comprehensive Report

Depredation, defined as the partial or complete removal of a hooked fish by a non-target species, is a cryptic form of mortality that can affect the accuracy of stock assessments and species management efforts. Accounting for depredation is crucial to minimize uncertainty in stock assessment models and to obtain accurate and reliable fisheries catch data. If these interactions are frequent, failure to properly quantify this form of mortality can lead to the underestimation of reef fish population removals, inappropriate harvest recommendations, and stakeholder unrest. In recent years, depredation has escalated in the Gulf of Mexico (GoM) reef fish fishery. Although GoM reef fish fishery stakeholders (fishermen) have actively pushed for resource managers to implement solutions to address these increasingly pervasive interactions, a comprehensive characterization of this issue is lacking, and trends surrounding GoM reef fish depredation – as well as factors that impact depredation – have not been adequately described or evaluated. Therefore, the objective of this project was to co-produce a shared characterization of the impacts of depredation in the GoM reef fish fishery. To accomplish this, we employed a three-phased approach consisting of synthesis (phase 1), survey (phase 2), and feedback (phase 3). During phase 1, we synthesized data from the NOAA Fisheries Southeast Fisheries Science Center (SEFSC) GoM Reef Fish Observer Program, the largest and longest depredation-related dataset available. Marked increases in depredation were shown starting in 2017 for both bottom longline and vertical longline, particularly in the Eastern GoM. To complement the analysis of the commercial sector from phase 1, we designed and implemented an electronic survey of private recreational anglers in phase 2. Survey results demonstrate that anglers across the GoM routinely experience depredation and have identified a variety of influential factors such as geographic location and depth. Surprisingly, depredation has not affected fishing behavior for the majority of those surveyed. Findings from the commercial fishery (phase 1) and private recreational fishery (phase 2) were then presented to a representative group of (predominantly) charter-for-hire fishermen during an in-person, collaborative participatory modeling workshop (phase 3). These stakeholders provided unique insights, suggesting that factors like the length of the red snapper fishing season, recreational angler high-grading, and a diminished GoM shrimp trawl fleet, have led to increases in depredation. Perhaps more importantly, these stakeholders noted a growing disconnect between their on-the-water observations (i.e., increased depredation), and what they perceived as an increasing desire from NOAA Fisheries and the general public to protect all sharks. Notably, these sentiments resulted in a lack of trust with respect to shark science, stock assessments, and resource management. Ultimately, this planning project led to a deeper understanding of shark depredation in the GoM commercial, private recreational, and charter-for-hire fisheries. Project findings formed the basis of a comprehensive Research and Development Plan and an Application Plan. In addition, data and insights from this planning project contributed to a peer-reviewed depredation review (Mitchell et al. 2022), a stock assessment report (Drymon et al. 2022), a manuscript in prep (Duffin et al.), five conference presentations, and three outreach products.