We sit perched on the sides of the modern dive tender and excitedly peak at the crystal-clear water, while defogging our masks and checking our dive gear one last time. When we get the long-anticipated ‘okay’ from our captain, we roll backward into the deeply blue waters off French Polynesia’s Fakarava Atoll.

As I descend and look towards the bottom, the strong current immediately sweeps me towards a seemingly endless coral reef with diverse species of soft and hard coral in myriad colours. But the healthy coral reef is not the star of the show. It’s the backdrop to something larger.

I’m quickly surrounded by large tornadoes of yellow snappers, numerous eagle rays, and seemingly endless fevers of grey reef sharks. Wherever I look, I spot these apex predators swim across the reef in their elegant side-to-side motion and notice that they’re keeping their distance from us divers. It’s a hopeful sign that they’re not being fed by humans to attract them to this special dive site.     

As we head back to our expedition yacht, Hanse Explorer, Tim Soper, EYOS founding partner and host of our bespoke trip, sums up the region’s beauty: “Polynesia is the ultimate warm water destination. The sheer number and variety of islands, the types of diving, the marine life, the clear water… you could spend a lifetime here and you could never get bored.”

Over the coming days, I am to learn exactly what he means. I experience some of the region’s most fantastic and obscure dive sites; I spot a humpback whale breaching in front of an inhabited island while sipping my morning coffee in comfortable solitude on the yacht’s upper deck; I meet some inquisitive dolphins; swim with humongous manta rays; and I marvel at countless colourful fish.

French Polynesia is full of life – and I want to dive deeper to find out how the nation has managed to protect its wildlife in times when biodiversity loss is rife in so many other parts of the world.

My investigation starts in Fakarava’s south pass where I spotted the famous ‘wall of sharks’ at the beginning of my trip. To find out why so many grey reef sharks gather here around the year, I meet up with Yannis P. Papastamatiou, associate professor of predator ecology and conservation at Florida International University.

Having worked on several studies that take a closer look at this topic, he explains that the Fakarava channel is an “amazing location for these sharks,” providing them so many of their needs. Not only does the channel offer plenty of food, but its currents provide a unique advantage for the species. As grey reef sharks are negatively buoyant, they will sink if they stop swimming. To meet their oxygen requirements – while there are some exceptions – they generally have to swim continuously to get enough water over their gills.

In the south pass, “during the daytime, tidal currents generate upwelling currents during the incoming tide because of the slope of the channel”, explains Papastamatiou. “By positioning themselves in these upwelling zones, they can keep themselves up in the water column with minimal swimming effort while the currents also drive fresh seawater across their gills. By doing this during the day, we estimate grey reef sharks reduce their energy expenditure by 20%.”

While Fakarava is a shining example of a biodiversity hotspot, French Polynesia – as a whole – is known for its large abundance of sharks. In 2006, the government of French Polynesia designated its entire exclusive economic zone as a sanctuary for sharks and rays to protect the species from overfishing – the first state to ban shark fishing across its entire marine territory. Within the protected 5.5 million square kilometres – an area half the size of Canada – fishing for rays and all sharks was now rendered illegal. After nearly two decades as a shark haven, the far-reaching protection seems to have been fruitful – at least from my diving observations.

On a more scientific level, a lack of data has made it hard to fully confirm the sanctuary’s success. While some researchers argue that illegal and accidental capture as bycatch within the protected area is still an issue, a report published in 2023 has put forward the first concrete evidence of the protection zone being effective.

The study titled ‘Citizen science provides valuable data to evaluate elasmobranch diversity and trends throughout the French Polynesia’s shark sanctuary’, published in the journal PLOS ONE, conducted by researchers from the Island Research Center and Environmental Observatory (CRIOBE) and the Polynesian Shark Observatory, found that the abundance of sharks has gradually increased in some areas by analysing citizen science data on sharks collected by divers and dive centres between 2011 and 2018.

“We could see that there was an extremely high diversity of species. There were also some places where there was an abundance of species considered globally endangered, which is important: Rangiroa or Tikehau where we found hammerhead sharks, which are critically endangered,” explained Clémentine Séguigne, who was involved with the study and works at CRIOBE. While the study sheds some positive light, she added, more data needs to be collected outside of popular dive spots “to prove the effectiveness of the sanctuary”.

Papastamatiou, on the other hand, believes that setting up the shark and ray sanctuary was a huge success.

“A global assessment of coral reefs in 2020 revealed French Polynesia to have some of the healthiest shark populations on the planet,” he says. “While French Polynesia also benefits from being remote, a major contributor to the healthy shark populations is going to be the sanctuary status.”

Political action is not the only reason French Polynesia’s diversity has been able to thrive. In fact, and so Julien Anton – a French underwater photographer and expedition leader who moved to Tahiti over a decade ago – tells me, the Polynesian people have been historically and culturally connected to their environment – especially the ocean – for many centuries.

“Man’s respect for nature is huge here,” he says. “Many species are protected in Polynesia, and for centuries, certain areas have been set aside to respect the reproductive cycles of animals, including those that are fished which means that the conservation in place for many years is effective and visible.”

The traditional ‘rāhui’ system, for example, plays a crucial role in French Polynesia’s local conservation efforts. The special practice involves restricting access to an area for a certain amount of time to allow resources to replenish and the environment to regenerate. Deeply rooted in Polynesian beliefs and culture, the system is effective in managing shared marine as well as land resources. Furthermore, whales are considered sacred in French Polynesia. Indigenous leaders recently heavily campaigned for whales being granted legal personhood. Now part of a recognised treaty, the initiative aims to enhance whale protection by assigning them legal rights.

To further protect these special animals, the government recently introduced new rules for humpback whale tourism, following years of increased demand for seeing – and swimming with – whales in French Polynesia. To combat over-tourism and harassing the whales which come here to mate, give birth, and nurse their calves, the new rules include a mandatory 300-metre observation zone, and a 100-metre exclusion zone around whales. Specific authorisation is now needed to enter these zones, while in-water interactions are limited to seven people, including guides.

“Overall, tourism is very important for conservation but there should be regulations,” explains Papastamatiou.

While French Polynesia continues to be a popular tourist destination, the government seems to reinvest a large amount of the money that tourism brings in to better study and protect sensitive areas. And to have as little impact as possible, yacht expeditions seem to become more popular too. Effectively helping to disperse tourist numbers so that popular dive sites become less crowded, yacht expeditions with companies that are aware of their ecological footprint and are involved with local conservation incentives can make a difference.

“Yacht expeditions are undoubtedly the very best way to discover Polynesia,” says Anton. “All the expeditions we lead and organise seek to include some type of animal studies for organisations attached to the Ministry of Ecology, such as Oceania, Te mana o te moana, or the Manta Trust.”

Rob McCallum, EYOS co-founder, adds: “After all, humans conserve what they value and understand.”

After experiencing the incredible diversity of French Polynesia for myself, I can see how tourism plays a crucial part in helping conserve biodiversity. When done correctly and paired with effective political action and far-reaching conservation efforts, the ocean can – and will – thrive.