Rewilding Atoll Islands May Help Them Adapt to Rising Sea Levels

Ecosystems and Island Resilience

Coral-fringed tropical atolls are highly vulnerable to global warming and rising sea levels. Research indicates that healthy ecosystems can enable these landforms to adapt to changing environmental conditions.

Nick Graham, a marine ecologist at Lancaster University, led a team that studied island resilience across 28 atoll islands in the Pacific and Indian oceans. Their findings suggest that these naturally active systems can change and adapt if allowed to function optimally.

Mechanisms of Natural Adaptation

The study, published in Science Advances, details how restoring atoll ecosystems reinforces their growth. Seabirds transport nutrients from the ocean, depositing guano that supports land plants, marine life, and coral growth. This process provides material for reef building.

Parrotfish and other reef feeders convert dead coral into sand, which helps maintain beaches. Native plants with extensive root networks further stabilize sediments, contributing to the atolls' structural integrity.

Restoration Strategies

Graham stated that eradicating rats and replacing coconut plantations with native forests and brush could give some atolls a "fighting chance" to persist against the rate of sea-level rise projected with approximately 2° Celsius of warming by the end of the century.

These restoration efforts aim to strengthen the dynamic system of seabirds, native vegetation, and reef systems, initiating a cycle where ecosystems become more self-sustaining and resilient to increasing environmental impacts.

Broader Implications for Climate Adaptation

These findings add to evidence that nature restoration can mitigate the effects of global warming. For example, restoring wetlands and forests can reduce the severity of wet and dry spells, thereby decreasing flood and fire risks.

Additionally, such restoration initiatives can contribute to slowing global warming by supporting natural carbon storage processes.