CONSERVATION & REEF HEALTH
Coral Conservation & Biorock Reefs in the Gili Islands
The Gili reefs were badly damaged by past fishing and warming seas — here's how Biorock restoration, turtle protection and diver habits are rebuilding them.
See Gili Islands diving on GetYourGuide ↗A reef that needed help
The coral reefs around the Gili Islands weren't always in the healthy state divers find today. Decades of destructive fishing practices, including blast fishing in the wider region, combined with anchor damage from boats and periodic coral bleaching linked to warming sea temperatures during strong El Niño years, left large patches of reef damaged or dead. As diving tourism grew through the 2000s and 2010s, it became clear that the islands' main economic asset — the reef itself — needed active restoration, not just protection from further harm, which is what drove the coral-restoration projects now visible around all three islands.
What Biorock actually is
The best-known restoration method used around the Gilis is Biorock (also called mineral accretion) — welded steel frames placed on the seabed and connected to a very low, safe electrical current, usually run from solar panels or nearby power sources. The current causes dissolved minerals in seawater to crystallise onto the steel, forming a limestone-like coating that coral fragments can be attached to and grow on far faster and more reliably than on bare rock or sand. Divers can see dozens of these structures — often shaped as domes, arches or sculptural forms — scattered around dive and snorkel sites near all three islands, gradually thickening with coral over the years.
Turtle protection efforts
Alongside coral restoration, local conservation initiatives on the islands have focused on protecting sea turtles, including hatchery and head-start programs that collect eggs at risk from natural or human threats, incubate them safely and release hatchlings into the sea — a way of improving survival odds during the most vulnerable stage of a turtle's life. Local dive centres and community groups have also worked to reduce turtle bycatch and discourage the historic, now largely stopped, practice of taking turtles or their eggs for consumption or trade. None of this makes turtle sightings certain on any given dive, but it's part of why they remain so consistently present around the islands today.
Who runs these projects
Much of the conservation work around the Gilis is coordinated through local marine conservation organisations working with community members and dive centres, funded partly through small per-dive or per-stay environmental contributions collected by participating operators. It's a genuinely grassroots model rather than a government-run reserve, which means the pace and coverage of restoration work depends heavily on local funding and volunteer involvement year to year. Divers curious about the details — which reefs are currently active restoration sites, or how the contribution schemes work — are best asking their own dive centre directly, since specifics can change.
What responsible diving looks like here
For visiting divers, the practical contribution is straightforward: keep well clear of the Biorock structures rather than touching or resting on them, since the electrical current and delicate new coral growth are both easily disrupted; maintain careful buoyancy over the wider reef; and choose reef-safe sunscreen, since some chemical sunscreens are linked to coral stress in high concentrations. Many operators also ask divers not to feed or touch marine life, including the turtles that are the main draw — partly for the animals' welfare, and partly because habituating turtles to human contact isn't good for them long-term.
Why this matters when picking a dive centre
Reef health directly determines how good the diving stays over time, which gives dive centres a genuine business incentive to support restoration rather than just market around it. When comparing operators, it's reasonable to ask whether they contribute to local reef or turtle projects, run small groups to limit diver impact on fragile sites, and brief guests on no-touch etiquette before entering the water — the answers are a decent proxy for how seriously a centre takes the reef it depends on, beyond what's written on its website. A centre that can explain its own environmental contribution in specific terms, rather than a vague mention, is usually one that takes the reef seriously in practice too.
More things to do nearby
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