Scientists in Phuket are banking frozen coral genetics against the day the reefs can be rebuilt. The question is whether Thailand’s tourism industry will give them that chance.
Thailand’s reefs have endured repeated mass bleaching events since 2022 – the cryobank is banking the genetics needed to rebuild them.
In a quiet laboratory at Phuket Rajabhat University, a molecular biologist called Preeyanuch Thongpoo is doing something that sounds like science fiction. She is freezing time. Inside vials no larger than a fingertip, suspended in liquid nitrogen at -196°C, are coral larvae and symbiotic algae – a living genetic archive of Thailand’s reef species. The goal: to keep these materials alive long enough for the reefs themselves to survive. The uncomfortable truth behind the project is this: nobody is certain they will.
The numbers are stark. Between January 2023 and April 2025, 84% of the world’s coral reef area experienced bleaching-level heat stress – the worst coral bleaching event ever recorded. Thailand’s reefs, home to more than 300 coral species, have not been spared. They have endured repeated mass bleaching events since 2022, compounded by tourism pressure, wastewater runoff, sedimentation and overfishing. Scientists are now openly asking not just how to restore these reefs, but whether there will be enough living coral left to restore from.
Preeyanuch’s cryobank is their answer to that question. Or at least, part of an answer.
Each vial holds the genetic material for future reefs – if the conditions ever exist to use them.
What a Coral Cryobank Actually Does
The principle is borrowed from plant seed banks – institutions like the Svalbard Global Seed Vault that archive the world’s agricultural diversity against catastrophic loss. Apply that logic to marine ecosystems and you get a coral cryobank: a cold-storage facility preserving coral reproductive material – larvae, sperm, and the symbiotic algae that corals need to survive – for potential future use in reef restoration.
The technique is called cryopreservation, and it has been used with coral materials for around two decades. What’s new is the scale of urgency. Preeyanuch’s facility, established in June 2025, is part of a wider regional initiative funded by CORDAP – the Coral Research and Development Accelerator Platform – to build the first network of coral larval cryobanks across the Coral Triangle, spanning Thailand, Malaysia, Indonesia and the Philippines. The network has already trained more than 124 researchers across these countries.
The science is intricate. Coral larvae are stored in ‘cryosticks’ submerged in liquid nitrogen, then thawed with a laser when needed. Chiahsin Lin, the Taiwanese researcher coordinating the regional effort, says the material can remain viable for 10 to 20 years – as long as the freezing protocol is optimal. The project initially focuses on pocilloporid corals, fast-growing weedy species that are among the first to colonise damaged reefs, making them valuable for accelerating recovery.
But cryopreservation is not a rescue plan. It is an insurance policy. And insurance only pays out if you’ve addressed the underlying risk.
What the Crisis Actually Looks Like
Thailand’s marine authorities have been candid about the scale of deterioration. The Department of Marine and Coastal Resources has outlined a 2025 restoration plan targeting coral replanting across 24 rai of reef across seven coastal provinces, with 60,000 coral colonies in active nurseries. The Andaman coast and Gulf of Thailand have both been affected by the bleaching cycle that has continued since 2022.
The pattern is well established globally. When ocean temperatures rise above a coral’s thermal tolerance threshold, it expels the symbiotic algae living in its tissue – the algae that give coral its colour and provide up to 90% of its energy through photosynthesis. Without them, coral turns white and begins to starve. Mild bleaching events allow recovery. Repeated severe events, arriving faster than reefs can rebuild, cause permanent structural collapse.
Thailand’s reefs experienced severe bleaching in both 1998 and 2010, with the 2010 event affecting 70% of coral in the Andaman Sea. The events since 2022 have compounded damage that was already accumulating. Scientists describe the gap between bleaching events as shrinking faster than reefs can recover.
The contrast between bleached and recovering reef tells the story more plainly than any statistic can.
The Honest Limits of Freezing
Every scientist involved in the Phuket project is careful to say the same thing: cryopreservation is not the solution. It is a tool.
Petch Manopawitr, adviser to the NGO WildAid and a Thai conservation scientist, describes the cryobank as providing a genetic insurance policy – important for preserving diversity in restoration programmes, particularly given that most existing efforts rely on coral fragmentation and cloning, which narrows the genetic pool. But he is direct about the limits: the banks won’t work unless the environmental conditions that degraded the reefs in the first place are fixed.
Preeyanuch’s first year at the Phuket facility has also encountered real difficulties. Maintaining broodstock corals in captivity long enough to collect viable larvae proved harder than anticipated. The team is adapting protocols and preparing for a second phase of CORDAP funding, but the work is slow by any measure – while climate-driven reef loss is not.
Lin, who leads the broader regional training programme, notes that preserving each coral species brings unique technical challenges. There is no single protocol that works across all 300-plus species found in Thai waters. Building genuine genetic diversity into the archive – rather than a narrow selection of easy-to-freeze species – will take years.
What This Means if You’re Diving in Thailand
If you’re planning to dive or snorkel in Thailand – or if you already have – this research matters directly. The reefs you visit are the reefs these scientists are trying to protect. And the way tourism is managed around those reefs determines whether there will be anything left to restore into.
Thailand’s marine authorities have linked reef degradation explicitly to tourism pressure, alongside climate change. Intensive diving and snorkelling activity cause coral breakage and tissue abrasion. Boat anchoring and propeller wash damage fragile reef structures. Rapid resort expansion around coastal areas generates wastewater discharge and sedimentation. In short: tourism done badly makes the cryobank necessary. Tourism done well makes it potentially unnecessary.
There are practical choices that make a difference. Dive operators that enforce no-touch, no-anchor policies, that limit group sizes, and that actively support local marine protection programmes deserve your business. Resorts that invest in wastewater treatment and coastal restoration over rapid expansion deserve your stay. If you’re unsure where to start, our guide to Southeast Asia’s underwater ecosystems covers how to assess operators and destinations against genuine sustainability criteria.
Choosing well isn’t a sacrifice. The best dive operations in Thailand – those that take marine protection seriously – tend to offer better experiences. Smaller groups, better guides, less disturbed marine life. The reef you want to see and the reef that survives are, to a significant degree, the same reef.
The future of Thailand’s reefs will be shaped as much by how tourists behave in the water as by what scientists do in the laboratory.
A Longer Game
The coral cryobank in Phuket represents something larger than the science itself. It is an acknowledgement, made in public and backed by funding, that the standard tools of reef restoration are no longer keeping pace. Conventional replanting of coral fragments – the dominant method for decades – cannot outrun bleaching events that arrive faster than reefs can recover.
The cryobank does not promise a solution. It preserves options. It says: when conditions stabilise, or when restoration science advances, or when marine protected areas grow strong enough, there will be material to work with. It is, as one researcher put it, the genetic heart of a restoration effort that hasn’t fully begun yet.
Whether that beginning arrives in time depends partly on decisions made far beyond Thailand – about emissions, about global ocean temperatures, about the pace of international climate action. But it also depends on decisions made much closer to shore. Which dive boat you book. Which resort you stay at. Whether the fish on your plate came from a sustainable source. These are not trivial choices when the alternative is a cold archive of frozen larvae and the hope that one day they might still be needed.
Read this week’s Unmasked Weekly for more on Thailand’s conservation landscape and what’s changing across the region.
