Study Reveals Snapping Shrimp Sounds as Coral Reef Health Indicators

A recent study published in the journal *Royal Society Open Science* has highlighted the potential of high-frequency sounds produced by snapping shrimp as effective indicators of coral reef health and resilience. The research, conducted by an international team of scientists, focused on underwater soundscapes surrounding Moorea Island in French Polynesia, particularly before and after two significant coral bleaching events in 2016 and 2019. This study represents a crucial step in marine conservation, as it explores a non-invasive method for monitoring reef ecosystems.

According to Xavier Raick, the study's lead author and a postdoctoral fellow at the K. Lisa Yang Center for Conservation Bioacoustics at the Cornell Lab of Ornithology, the acoustic monitoring of snapping shrimp during nighttime proved particularly insightful. Raick stated, "The high-frequency sounds, mainly during the night, of snapping shrimp can be used as a real indicator of coral resilience. Snapping shrimp's abundance is a mirror of coral cover. So if you have more corals, especially very big colonies, you have more snapping shrimps, and then you can use their sound as a proxy for the reef structure and health."

The study utilized underwater microphones to capture and analyze sound data from both protected and unprotected coral reefs, alongside visual surveys of fish populations and benthic organisms. This comprehensive approach allowed researchers to assess the resilience of coral reefs more realistically, moving beyond traditional comparisons of pristine and severely damaged reefs.

The findings revealed that protected coral areas exhibited a notable increase in snapping shrimp activity after bleaching events, suggesting that marine protected areas (MPAs) enhance reef resilience against climate-induced stressors. Raick emphasized the importance of these findings, saying, "For managers, using these high frequency sounds made by snapping shrimps is a very interesting tool. While scuba diving surveys are typically conducted only during the daytime, acoustic monitoring can provide a continuous and comprehensive view of reef health."

The implications of this study are profound, as it suggests that incorporating acoustic monitoring into long-term reef management strategies could enhance conservation efforts. Traditional monitoring techniques often rely on costly and time-consuming scuba diving, which may not capture the full picture of reef dynamics, particularly during nocturnal hours when snapping shrimp are most active.

While the research presents significant advancements in understanding coral resilience, Raick acknowledges the need for further studies across diverse marine environments to validate these findings. "It's a story on one island and needs to be repeated in other parts of the world," he noted, underscoring the necessity of broader research to establish a more comprehensive understanding of coral reef ecosystems.

As global coral reefs continue to face severe threats from climate change, pollution, and overfishing, innovative monitoring approaches, such as the acoustic assessment of snapping shrimp, could play a pivotal role in the future of marine conservation. The study not only adds to the body of knowledge regarding coral reef health but also opens new avenues for sustainable management practices that could help preserve these vital ecosystems for generations to come.

For further details, refer to the original study: Raick, X., et al. (2025). Highlighting the resilience potential of marine protected areas in the face of coral bleaching with passive acoustic monitoring. *Royal Society Open Science*. DOI: 10.1098/rsos.241938.