Photo: Anton Levantov
Ayyalon Cave, Israel
An Ecosystem Powered by Sulphur, Not Sunlight
Deep beneath the surface of Israel’s coastal lowlands, hidden from the world above, lies one of the planet’s most extraordinary ecosystems: Ayyalon Cave.
Discovered in 2006 within the Nesher‑Ramla quarry, this subterranean world is unlike any other on Earth. With its unique biochemical processes, this cave hosts a thriving ecosystem based entirely on chemosynthesis — not sunlight.
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The cave is home to one of the few known sulphide‑rich, autotrophic food webs that are found in caves. Instead of relying on photosynthesis, the organisms here rely on sulphur‑oxidizing bacteria to produce energy, creating a self‑sustaining cycle of life that is totally disconnected from the surface world.
The Cave’s Unique Biodiversity
Ayyalon Cave is not just an ecological oddity — it’s a living time capsule. The organisms that thrive here have evolved over millions of years in total isolation.
The cave’s sulphuric pools and microbial mats provide an environment where a range of specialized species, many of which are blind, pale, and found nowhere else on Earth, live and feed. Species like the blind shrimp Typhlocaris ayyaloni, several species of zooplanktonic crustaceans, and an endemic species of springtails, exist here in ways that science has only just begun to understand.
Photo: Boaz Langford
GReG member Tamar Guy-Haim examining Typhlocaris ayyaloni at the Ayyalon cave.
This ecosystem, untouched by the usual forces of natural selection found on the surface, offers a window into an entirely different way of life — a reminder of just how adaptable life can be, even in the harshest of conditions.
Photo: Anton Levantov
GReG member Oren Kolodny collecting copepods at Ayyalon cave.
Why Ayyalon Cave Matters
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A Global Rarity: Ayyalon Cave is one of few known ecosystems in the world that is completely independent of sunlight. It provides a rare opportunity to study life in a completely alien environment.
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Evolution in Action: The species found in Ayyalon Cave are the result of millions of years of adaptation to subterranean life, offering clues about the long‑term processes of evolution and specialization.
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Critical for Hydrology: The cave taps into the Yarkon‑Taninim Aquifer, a major water source for both Israel and the Palestinian territories. Protecting the cave also means protecting the aquifer’s delicate hydrological balance.
The Battle to Protect Ayyalon Cave
Ayyalon Cave has been preserved in relative isolation for millions of years, but recent human activity threatens its future. The cave lies within an active quarry, and mining operations have altered the surrounding hydrology. The threat of pollution and disruption from the surface is constant, and the cave’s ecosystem is incredibly fragile.
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In 2021, the cave faced a critical threat when a plan was proposed to divert seasonal runoff from the Ayyalon River into the Nesher‑Ramla quarry, effectively flooding the cave with fresh, cold, and oxidized water. This change would have irreparably altered the sulphide‑rich water-balance that sustains the cave’s food web, endangering its delicate inhabitants.
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But, in a rare win for conservation, scientists, environmentalists, and the public rallied together. A vocal coalition of academics, NGOs, and concerned citizens worked tirelessly to raise awareness of the cave’s unique value. The campaign succeeded in pushing the National Infrastructure Committee to revise the plan, ensuring that Ayyalon Cave would not be flooded. This victory is an example of how coordinated efforts can lead to positive outcomes for conservation.
Photo: Oren Kolodny
Ayyalon cave is within an active quarry, and the ecosystem faces multiple threats.
A Living Laboratory for Future Generations
Ayyalon Cave is a stark reminder of the biodiversity that thrives in the most unexpected places. It’s a place where life finds a way. It also shows us the power of collaboration — when scientists, the media, public stakeholders, and policymakers work together, real change can happen.
The future of Ayyalon Cave is far from secure, but this conservation success offers hope. It reminds us that even in an era marked by environmental crisis, positive stories of conservation are not just possible — they’re essential. And, as we look ahead, there’s a powerful lesson: to protect what’s precious, we must continue to act with determination and optimism.