A new study published in the journal Environmental Research Letters on June 16, 2026, reveals that coconut plantations established during the colonial era on Pacific atolls are accelerating the islands' vulnerability to sea-level rise. Researchers from the University of Auckland and the Pacific Community found that these monoculture farms reduce the natural recharge of freshwater lenses—the underground layers of fresh water that float atop saltwater—by up to 40% compared to native forest cover.
The study focused on atolls in Kiribati, Tuvalu, and the Marshall Islands, where coconut palms were planted extensively in the late 19th and early 20th centuries for copra production. Unlike diverse native vegetation, coconut palms have shallow root systems that do not effectively capture rainfall and allow more evaporation, leading to smaller and more saline freshwater lenses. This makes the islands less resilient to droughts and storm surges, which are becoming more frequent with climate change.
Lead author Dr. Sarah Johnson stated, 'These plantations were designed for economic extraction, not for island sustainability. Restoring native vegetation could improve freshwater security and slow the rate of land loss.' The researchers estimate that replacing coconut monocultures with mixed native forests could increase freshwater availability by 30% and reduce erosion rates by half.
Local governments are now considering phased removal of some plantations, but face challenges from economic dependence on coconut exports and land tenure issues. The study calls for international funding to support ecological restoration as part of climate adaptation strategies for atoll nations.
