Bahasa Indonesia

Marine conservation faces a critical challenge: how to protect endangered species while supporting fishing communities that depend on marine resources for their livelihoods. One promising approach involves paying fishers to release endangered animals alive rather than keeping them for sale. However, a study from Indonesia reveals that such programs can have unintended consequences that significantly reduce their conservation impact.

Researchers conducted the first-ever randomized controlled trial of a pay-to-release program for marine animals. The study focuses on two critically endangered species: hammerhead sharks and wedgefishes. These animals are among the most threatened marine species on the planet, primarily due to overfishing in both targeted and accidental catches.

The study aimed to test whether financial incentives could effectively reduce mortality of these endangered species while ensuring that fishing communities weren’t economically harmed by conservation efforts. The research team worked with 87 fishing vessels across five villages in two Indonesian regions over 16 months. They used a crossover design where vessels alternated between receiving payment offers and control periods with no payments. This experimental approach allowed the researchers to compare what happened when the same vessels had access to payments versus when they didn’t.

Fishers could receive payments for submitting videos of live releases taken on program-provided cameras. Payment amounts varied by region based on local market values — ranging from about US$1 to $34 for hammerheads and US$8 to $134 for wedgefishes, depending on location and size. The research team monitored both the number of live releases (through submitted videos) and the total catch of dead animals (through daily surveys at landing sites) throughout the entire study period.

Using conventional monitoring methods — simply counting live releases — the program appeared highly successful. The researchers calculated a 71% reduction in wedgefish mortality and a 4% reduction in hammerhead shark mortality based on the number of animals released alive. However, the experimental design revealed a more complex picture. When comparing total catches during payment periods versus control periods, the actual conservation benefits were much smaller. The program only achieved a 25% reduction in wedgefish mortality. Even more concerning, hammerhead shark mortality actually increased by 44% during payment periods.

The discrepancy between conventional monitoring results and experimental findings revealed that some fishers were engaging in “hidden actions” — increasing their fishing effort when payments were available. The offer of payments incentivized some vessels to catch more of the target species, knowing they could release smaller, less valuable individuals alive for payment while keeping larger, more valuable ones. This pattern was particularly pronounced in villages that received most of the payments. The correlation between hammerhead and wedgefish catches was 37% higher during payment periods compared to control periods, suggesting that efforts to catch one species led to increased catches of the other.

The different outcomes for hammerheads versus wedgefishes reflect important biological differences. Wedgefishes have relatively high survival rates after capture (up to 90%) due to their respiratory system, making live release more viable. Hammerheads, conversely, have much lower post-capture survival rates (around 50%) because they need to swim constantly to breathe, making it harder to release them alive successfully.

This study offers several crucial lessons for animal advocates working on marine conservation:

• First, it demonstrates the critical importance of rigorous evaluation before scaling up conservation programs. Without experimental design, this program would’ve been considered successful and likely expanded, potentially causing more harm than good to endangered hammerhead populations.
• Second, the research shows that financial incentive programs require careful design that accounts for ecological factors like post-capture survival rates and economic factors like the relative value of different-sized animals.
• Third, advocates should consider that pay-to-release programs may work better as part of a broader conservation strategy rather than standalone solutions. The authors suggest combining individual payments with community-level incentives and complementary measures like spatial closures or gear modifications.

The study also highlights the need for advocates to push for experimental evaluation of conservation interventions, even when programs seem intuitively beneficial. As the researchers note, “even the most careful efforts to design a conservation program may not account for all types of real-world uncertainties and complexities.” While this study doesn’t prove that pay-to-release programs can’t work, it provides valuable insights for designing more effective marine conservation programs that truly benefit endangered species while supporting fishing communities.