Coral reefs are not only home to marine life: they also help protect coastlines by reducing the force of ocean waves. In this study, we used 30 years of satellite data to understand how well coral reefs perform this protective role around the world.

We analyzed how wave height changes before and after waves pass over coral reefs, using improved satellite measurements that allow us to study wave behavior close to shore. We also looked at how reef structure and health, especially during major climate events like El Niño, affect this wave reduction.

Our findings show that in 80% of cases, waves are significantly smaller after crossing a reef. On average, wave height drops by about 50% during rougher sea conditions. This shows that coral reefs play a vital role in protecting coastal communities from strong waves and erosion. Our work also highlights how long-term satellite data can help us monitor and understand the benefits that healthy reefs provide.