Island Ecosystems Under Pressure: Scientific Insights into Degradation and Recovery

• May 30, 2025

Islands are home to species found nowhere else on Earth. They face threats from human activities and climate change, that demand urgent, innovative solutions. Here’s how science, community, in projects like PHAROS are helping islands thrive.

Why Island Ecosystems Are on the Brink

Islands account for just 5% of Earth’s landmass but harbor 20% of all species. Their isolation now magnifies their vulnerability.

Invasion of the Silent Destroyers

Introduced species like rats, cats, and ants have decimated island biodiversity. In Hawaii, tropical fire ants attack seabird chicks, causing tissue loss in their feet, while invasive mynas steal up to 20% of shearwater eggs. On Mauritius, feral cats and rats threaten endemic birds like the pink pigeon, a species already haunted by the ghost of the dodo. These invaders exploit islands’ low biodiversity and naive prey, which lack evolutionary defenses.

Chainsaws and Climate

In Madagascar, slash-and-burn agriculture (tavy) has reduced forest cover to 12%, with shortened fallow cycles causing soil erosion and invasive plant takeover. Meanwhile, coral reefs, the lifeblood of many islands, are bleaching catastrophically. By 2050, Indian Ocean corals may vanish, collapsing marine ecosystems that sustain both wildlife and coastal communities.

The Double Jeopardy of Small Populations

Island species often exist in tiny, isolated populations. A single hurricane or disease outbreak can erase millennia of evolution. For example, the golden-crowned sifaka, a lemur endemic to Madagascar, teeters toward extinction due to bushmeat hunting and habitat loss.

Eradication and Resurrection

The formula for revival is simple in theory: remove invasive species, reintroduce natives. Redonda, a Caribbean island once overrun by rats and goats, transformed from a barren rock to a green oasis after a 2016 restoration campaign. Seabirds returned, vegetation regrew, and endemic lizards rebounded – a proof that even severely degraded ecosystems can heal.

Coral Cryopreservation and Super Reefs

At Australia’s Great Barrier Reef, scientists cultivate heat-resistant corals in nurseries, transplanting them to bleached areas. In 2022, these “super corals” boosted recovery in 41% of inshore reefs. Projects like the Reef Restoration and Adaptation Program (RRAP) also explore genetic tweaks to accelerate adaptation, blending human ingenuity with nature’s resilience.

Community as Guardians

In the Seychelles, locals monitor turtle nests and remove invasive plants. Their traditional knowledge, paired with drone surveys and AI, creates a hybrid model of conservation—one that’s scalable and sustainable.

PHAROS: Blueprint for a Resilient Future

The EU-funded PHAROS project is a bright example how cutting-edge science and community collaboration can restore island-ocean ecosystems;

Multi-Trophic Aquaculture in Gran Canaria

PHAROS’s Integrated Multi-Trophic Aquaculture (IMTA) system in Gran Canaria mimics natural food webs. Macroalgae absorb CO2, filtering water for abalone and sea cucumbers, while artificial reefs provide habitat for fish. Real-time sensors track progress, feeding data into a Digital Twin Ocean model to predict outcomes.

Fighting Invasives with eDNA in Iceland

In Iceland’s rivers, PHAROS deploys environmental DNA (eDNA) to detect invasive pink salmon. This early-warning system allows rapid response, protecting native trout and Arctic char, which represents a win for biodiversity and Iceland’s $2 billion fishing industry.

Living Labs: Empowering Coastal Communities

PHAROS’s Living Labs in Ireland and the Canary Islands turn locals into citizen scientists. Using the MINKA platform, they log sightings of endangered species and monitor water quality, ensuring restoration aligns with cultural and economic needs.

The Road Ahead

Island ecosystems are canaries in the coal mine for global biodiversity. Their plight underscores a universal truth: isolation is no match for globalization’s reach. Yet projects like PHAROS prove that targeted interventions, rooted in science, powered by communities can tip the scales toward recovery.

The challenge is vast, but the tools are at hand. From CRISPR-edited corals to AI-driven monitoring, the next decade will test whether humanity can transition from exploiters to architects of renewal. For islands, the stakes are nothing less than existence itself.

References

• Australian Institute of Marine Science. (2022). Great Barrier Reef restoration progress report.
• Platenberg, R. et al. (2020). Impacts of invasive species on island ecosystems. Journal of Island Ecology.
• Russel, J. C. et al. (2019). Island vulnerability to biological invasions. Conservation Biology.
• PHAROS Project. (2025). Annual report on marine ecosystem restoration. European Commission.
• Island Conservation. (2024). Redonda Island restoration case study.