A groundbreaking study from the University of Oxford has shown that pay-to-release incentive programs can significantly boost the live release of endangered marine species caught as bycatch. However, the study also uncovered that these incentives, if not carefully designed, may lead to unintended consequences.
Published in Science Advances, this research marks the world’s first randomized controlled trial evaluating the real-world effectiveness of an incentive-based marine conservation program.
Why Incentive Programs Matter in Marine Conservation
Large marine animals like sharks and rays are among the most critically endangered species globally, mainly due to overfishing and bycatch. In many small-scale fisheries, coastal communities heavily rely on marine resources for food and income, creating a tough balancing act between biodiversity conservation and human livelihoods.
Incentive programs offer a promising, cost-effective strategy to support both people and nature. But as this study reveals, they must be carefully designed to avoid unexpected behaviors.
Inside the Study: How Pay-to-Release Programs Were Tested
The Oxford team, in collaboration with the local NGO Kebersamaan Untuk Lautan (KUL), launched a pay-to-release program in Indonesia. Fishers were compensated for safely releasing two critically endangered groups: hammerhead sharks (Sphyrna) and wedgefish (Rhynchobatus).
Key points of the study:
- Duration: May 2022 – August 2023
- Participants: 87 vessels, randomly divided into a treatment group (eligible for payments) and a control group (no payments).
- Verification: Fishers recorded videos using waterproof cameras to prove safe releases.
- Compensation: Payments matched the estimated market value of the released animals.
The results were striking:
- 71% of caught wedgefish were released alive.
- 4% of caught hammerhead sharks were released alive.
Yet, the study also found that some vessels increased their fishing efforts to maximize their payouts, which reduced the overall conservation gains.
Adjustments for a Better Future
Recognizing these challenges, KUL quickly adapted the program:
- Adjusted payments based on fish size classes.
- Capped the number of compensated releases per vessel per week.
- Launched gear swap programs to prevent endangered species from being caught in the first place.
Preliminary findings from these adjustments are promising, and further trials are ongoing with support from the UK’s Darwin Initiative.
Expert Insights: Why Rigorous Evaluation Is Essential
Dr. Hollie Booth, lead researcher at the University of Oxford, emphasized:
“Incentive-based programs are crucial for fair and effective conservation. However, they must be well-designed and rigorously tested to ensure they truly benefit both nature and communities.“
Similarly, Professor Paul Ferraro from Johns Hopkins University highlighted the need for scientific evaluations:
“It’s concerning that many conservation programs are rolled out without checking if they actually work. We must invest in programs that show real benefits for biodiversity and local livelihoods.“
Teuku Ridwan, Head of the Department of Marine Affairs and Fisheries in Aceh Jaya, praised the initiative:
“This project strengthens the livelihoods of small-scale fishers, the backbone of Aceh’s coastal communities. Collaboration among all stakeholders is key for sustainable marine management based on local wisdom.“
Conclusion: Building a Future Where Nature and People Thrive Together
The study underscores a vital lesson for marine conservation: even the best-designed programs must be piloted, evaluated, and adapted based on real-world feedback. With smarter incentives and stronger collaborations, we can bend the curve on biodiversity loss and move closer to achieving the Global Biodiversity Framework’s 2050 vision of “living in harmony with nature.”
Reference:
Hollie Booth et al., “Conservation impacts and hidden actions in a randomized trial of a marine pay-to-release program,” Science Advances (2025). DOI: 10.1126/sciadv.adr1000
Provided by:
University of Oxford