Study: seabirds, native plants and rat removal may help atolls keep up with sea-level rise

Left · 2A study published Wednesday 14 October 2026 in Science Advances reports that restoring atoll ecosystems may help low-lying coral islands keep pace with rising seas. 1 2 Left · 2An international team led by Nick Graham, a marine ecologist at Lancaster University in the UK, studied 28 atoll islands in the Pacific and Indian oceans, including islands in the Seychelles and Chagos archipelagos and Tetiaroa in French Polynesia. 1 2 Left · 2Terrestrial ecologists, marine ecologists and geomorphologists combined measurements of seabird populations, native vegetation, and coral and reef organisms, using an approach called ecosystem energetics that treats energy flow as a common currency across organisms usually studied separately. 2 1

Left · 1The proposed mechanism is a cycle: seabirds feed at sea and deposit nutrient-rich guano on the islands, which feeds land plants, marine life and coral growth. Parrotfish and other reef feeders turn dead coral into sand, and native plants with dense root networks stabilise the shallow soil, while coconut palms have small, unstable rootballs that leave soil prone to erosion. 2 Left · 2The study measured "reef accretion potential" and found it twice as high on lagoonal and ocean-facing reefs around rat-free islands with abundant seabirds as around rat-infested islands. Co-author Casey Benkwitt, a restoration scientist with The Nature Conservancy, said that would be "sufficient to closely keep up with predicted sea-level rises to the end of the century under a 2 degree Celsius warming scenario", and that reef growth without seabirds is less likely to keep pace. 1 2 Left · 2Graham said eradicating rats, which were brought by colonisers and have devastated seabird colonies for centuries, and replacing coconut plantations with native forest and brush could give some atolls a "fighting chance" to persist at the sea-level rise expected late this century with about 2°C (3.6°F) of warming. 1 2

Left · 2Graham cautioned that the study is not a miracle solution. It did not make direct before-and-after restoration comparisons, the islands differed in seabird abundance and rat infestation (differences the team tried to smooth out with the energetics framework), and it focused on mostly uninhabited or sparsely populated islands. 1 2 Left · 2Graham also noted that reef accretion does not always mean an atoll is growing vertically, because warming is changing waves, winds and currents that affect where material ends up, and that on developed atolls restoration can help but will not replace engineering solutions. 2 1 Left · 2In a Science Advances Focus commentary, ecologist Hillary Young called the work a nearly complete loop from seabirds through native forests and reefs back to island building, and said atoll land and sea cannot be managed separately. Young added that local conservation can influence physical resilience but that rapid cuts in greenhouse-gas emissions remain essential to the systems' long-term viability. 2 1

Left · 2Context cited in the coverage: a 2026 study of 288 reef core growth records found most reefs kept pace with rising seas, though that capacity varied by location and is not guaranteed at the current rate of warming. 1 2