The highest reward in an athlete's career is winning an Olympic medal or a world championship. For marine conservationists, a similar success is witnessing a whale shark returning to feed in a restored area.
Nittakan Hemin, a marine researcher who enjoys diving as a hobby and has spent years helping to restore degraded coral reefs around Koh Tao, Surat Thani, achieved that pedestal moment.
For her, the sight of the gentle giant gliding through waters once devastated by bleaching was more than a personal triumph -- it was proof the ocean can heal when given a chance.
The restoration is part of a long-term marine environment project carried out by PTT Exploration and Production Plc (PTTEP), the petroleum drilling arm of national oil and gas conglomerate PTT Plc.
PTTEP has supported efforts to restore or build new habitats, using shipwrecks, artificial reefs and most recently underwater sculptures to bring life back to the sea.
The company said it has a clear mission with these projects: building homes for marine life and new diving sites that not only protect fragile ecosystems, but also sustain local communities.
The return of whale sharks, highly migratory and sensitive to environmental changes, is a living report card of success -- an indicator that the food chain is recovering and conservation efforts are paying off.
REVIVING A BLEACHED REEF
Thailand began restoring damaged coral reefs by creating man‑made dive sites, giving natural reefs a chance to recover.
In 2011, the waters around Koh Ngam Noi in Chumphon suffered severe coral bleaching when sea temperatures rose above 30.5° C for weeks. The reefs turned white and lifeless, leaving fish without shelter and hurting local fishing families.
Scientists and conservationists realised if divers kept visiting fragile reefs, recovery would be impossible. So they proposed building artificial dive sites where marine life could slowly return.
With support from PTTEP, the first underwater learning park was created near Koh Ngam Noi. Later, the project expanded to Koh Tao, one of the country's busiest diving destinations.
Shipwrecks and artificial structures were placed underwater to act as new homes for marine life.
Over time, barnacles, corals and sponges grew on them, attracting small fish and eventually larger species.
Ms Nittakan, who joined the restoration work in those early years, returned more than a decade later to find more than 60 species of fish thriving again at the shipwreck site.
She said it was like seeing old friends come home.
"Many marine species came back, especially whale sharks," said Ms Nittakan.
For her, the return of whale sharks feeding in the area was the clearest sign that the ecosystem had recovered and was alive once more.
SCULPTURES BENEATH THE WAVES
On Koh Tao, PTTEP has taken marine restoration a step further by combining science with art.
The company, working with the Department of Marine and Coastal Resources (DMCR), recently launched the "Ocean for Life" project, an underwater sculpture park designed to restore ecosystems while creating a new attraction for divers.
Chayong Borisuitsawat, executive vice‑president for technology, carbon solutions and sustainable growth at PTTEP, said the sculptures are part of a broader plan to reduce tourist pressure on natural reefs and accelerate recovery.
The site features nine large sculptures shaped like marine animals, including whale sharks, manta rays and sea turtles. Each piece stands about 2.5 metres tall and is made from materials safe for marine life.
Alongside the sculptures, more than 90 artificial reef structures such as coral balls and domes have been placed across a 10,000‑square‑metre area known as Buoyancy World, a scuba training dive site, about 100 m off Koh Tao's coast.
These structures are more than just art -- they act as new homes for fish, corals and other sea creatures, helping to rebuild biodiversity in waters that have been stressed by tourism and climate change.
PTTEP and DMCR plan to monitor the site every three years, checking how well marine life is returning and how the ecosystem is adapting.
For Koh Tao's diving community, the sculptures are already a symbol of hope -- a reminder that conservation can be creative, practical and beneficial for both nature and people.
REPURPOSING PLATFORMS
PTTEP is preparing to take marine restoration into deeper waters by turning retired petroleum platforms into artificial reefs, said Mr Chayong.
He said the company plans to use decommissioned platforms in the Gulf of Thailand to create new habitats for marine life.
The project is expected to begin in the second half of 2026, starting off in Pattani province.
By placing the large steel structures on the seabed, PTTEP hopes to build ecosystems that can support fish, shellfish and other marine species, said Mr Chayong.
The company believes the effort will not only increase fish populations, but also promote sustainable fishing for local communities.
Officials from the Department of Fisheries note the idea of using man‑made structures to restore marine life is not new. Thailand first experimented with artificial reefs between 2001 and 2003, following an initiative by Her Majesty Queen Sirikit The Queen Mother.
Early projects used decommissioned train carriages and cement pipes to provide shelter for marine animals, laying the foundation for more advanced schemes, said the department.
PTTEP aims to build on that legacy, and the scale of the structures means they can host entire ecosystems, much like natural reefs.
Marine scientists said this approach mirrors successful programmes in the US after World War II, where decommissioned ships and platforms were sunk to create thriving dive sites and habitats.
KOH TAO CONSERVATION
Locals on Koh Tao demonstrate how conservation and tourism can work together.
Ramluek Assavachin, head of the Koh Tao Tourism Association, said local entrepreneurs have long worried about the island's environment.
Many businesses started projects to reduce waste and protect both land and sea, including cutting down on foam containers and single‑use plastics.
She said Koh Tao is promoted as a green destination, with activities such as coral reef rehabilitation, mooring buoy maintenance, beach clean‑ups and forest restoration. These efforts are meant to raise awareness among tourists and residents while keeping the island attractive for diving.
Since the pandemic, more than 70 diving schools have opened or expanded on Koh Tao. With so many visitors, Ms Ramluek said it is important to teach divers how to care for the underwater environment: avoiding stepping on coral, managing waste properly and respecting marine life.
She said a new campaign aims to cut single‑use plastics by half before the end of this year.
For PTTEP, these community efforts are vital. The company's artificial reef projects can only succeed if local businesses and divers help protect the sites.
By working together, Koh Tao's tourism industry and conservation groups hope to maintain the island's reputation as one of the world's most popular diving destinations, while ensuring the sea remains healthy for future generations.
For Ms Nittakan, the return of a whale shark to Koh Tao was the clearest sign that restoration efforts were working.
PTTEP said its projects, whether sinking navy ships, building sculpture parks or planning artificial reefs from petroleum platforms, show how industry, government and communities can join forces to heal the sea.
These collaborations prove marine life and local livelihoods can thrive together when conservation is a shared mission, noted the company.
