Human Impact on Coral Reefs: Immediate Actions for Long-term Solutions

The devastating impact of climate change on coral reefs is globally recognised, but the specific damages caused by human activities have largely remained unproven until now. A recent paper published in Nature, based on a 20-year study of coral reef health in Hawai’i, demonstrates the undeniable contributions of human impact to declining coral reef health.

The study, conducted by Arizona State University, the National Oceanic and Atmospheric Administration’s Pacific Islands Fisheries Science Centre (PIFSC), and Bangor University in the U.K., indicates that mitigating local land and sea-based human impacts – particularly pollution and overfishing – offers the best chance for coral reef ecosystems to survive climate change. Particularly in densely populated coastal areas of Hawai’i wastewater pollution, urban runoff, and fishing pressures heavily stress coral reefs.

The research highlighted that reefs with lower levels of local land-based stressors and higher fish populations suffered less coral loss during the historic marine heatwave of 2015. This points to the significant role of local land-sea conditions in coral reef survival.

Greg Asner, senior author of the study, emphasized the urgent need for policy efforts to address these human-caused threats. “Some of these issues will take longer to mitigate, but some can see positive change now,” said Asner.

The paper supports the philosophy that integrated land-sea management is a critical component of coral reef conservation.

“Only by adopting coupled land-sea policy measures, alongside global reductions in greenhouse gas emissions, will coral reef ecosystems have the best opportunity for persistence in our changing climate,” concluded Gareth Williams, co-lead of the study.