Depredation in Florida’s Recreational Fisheries

Using a citizen-science approach to characterize shark depredation in the recreational fisheries of the southeast United States

NOAA/NMFS Co-operative Research Program FY21. PI: Matthew Ajemian (FAU-HBOI); Co-PIs: Lauran Brewster (SMAST), Marcus Drymon (Mississippi State University)

Background and relevance:

Shark depredation is an emerging issue that is purportedly affecting several non-HMS (snapper-grouper, coastal migratory pelagic, dolphin/wahoo) as well as select HMS (e.g., tunas and billfishes) fisheries in the southeastern US. While the NOAA Office of Sustainable Fisheries recently produced a report on shark depredation in commercial fisheries (i.e., pelagic/bottom/vertical longlines), there have been no attempts to quantify these interactions in recreational fisheries that heavily support the economies of this region. As indicated in the recent HMS AP meeting, these data are sorely needed to characterize the scale of the issue and determine the need for (and types of) mitigation measures. However, characterization of this issue is impossible without stakeholder involvement. Here, we propose a citizen-science based approach to 1) acquire depredation data (composition, frequency, etc.) in the recreational sector via leveraging our existing fishing partnerships, and 2) evaluate fishermen perceptions of the issue.

Goals: We have addressed two major goals, using a number of complementary techniques (indicated in parentheses):
Goal 1: Characterize depredation in non-HMS recreational fisheries.
1. Which species are being depredated upon? (Social Media Analysis, Cooperative Surveys)
2. Which species depredate non-HMS catch and at what rates? (Genetics, Video Analysis, Cooperative Surveys)
3. What environmental (e.g. sea surface temperature, time of day, distance from shore) or fishing (e.g. angler experience, bait, target species) conditions influence depredation rates? (Cooperative Surveys, Fishermen Surveys)
Goal 2: Evaluate fishermen perceptions of depredation
4. What are fishermen’s perceptions of depredation rate trends and how do these align with empirical data? (Fishermen Surveys)
5. What species do recreational fishermen perceive as key depredators? (Fishermen Surveys)
6. Can fishermen identify additional covariates that significantly influence depredation rates? (Fishermen Surveys, Social Media Analysis)
7. Does depredation affect fishermen practices or motivation to fish? (Fishermen Surveys)
8. How do fishermen’s perceptions of depredation rates influence their stance on management of HMS (shark) species? (Fishermen Surveys)

We have just wrapped up analysis for this project. Stay tuned for the upcoming publications.

Reducing Interactions Between Sharks and Snapper/Grouper Fisheries Through Novel Deterrent Devices

NOAA/NMFS Bycatch Reduction Engineering Program FY22. PI: Matthew Ajemian (FAU-HBOI); Co-PIs: Lauran Brewster (SMAST), Stephen Kajiura (FAU), Marcus Drymon (Mississippi State University)

Our overall goal is to improve our scientific understanding of ways to mitigate shark depredation in snapper-grouper fisheries. We are addressing this by fulfilling three major objectives:
1. Test and quantify the magnetic field dynamics of a novel shark depredation deterrent
2. Incorporate deterrents into fishing activities with stakeholders and assess efficacy
3. Disseminate results to stakeholders involved in snapper-grouper fisheries

We will be wrapping up the data collection for this project in 2024. Stay tuned.

Instructional infographic demonstrating proper swab sampling protocol and technique for charter fishing partners. 

Seasonal (round) and regional variation in the percentage of respondents that experienced depredation while saltwater fishing in there preceeding months.

Excerpt from online survey distributed to Florida recreational fishing license holders