In French Polynesia, sharks have been living in a haven of peace since 2006. The local government has set up a sanctuary for the twenty or so species that reside and swim in these South Pacific waters. A measure as rare as it is exceptional that would demonstrate positive results for their protection.
In the humid heat off the east coast of Tahiti, three divers fall backwards from the edge of their boat. After making the final adjustments to their equipment, they slowly begin their descent into the deep blue of the Pacific Ocean. A few minutes later, the group reaches a depth of 15 meters. A school of paddlefish seems to fly above their heads. A titan triggerfish with blue and green scales undulates its dorsal fin and darts in the opposite direction. In this majestic landscape where coral reefs are important refuges for biodiversity, fish, sea urchins and moray eels play hide-and-seek.
As the instructor passes through a cave, he places his right hand, fingers linked, on top of his head to signify a fin. A group of three nurse sharks, including a juvenile, are resting. They are one of the most vulnerable species in the world, with a declining population, according to 2020 data from the International Union for Conservation of Nature (IUCN).
Nearly ten sharks per dive
Time stands still for the divers. Before their expedition, they were given strict instructions: stay grouped together, far enough away from the sharks and avoid making too much noise. Despite the current, they try to maintain their stability. Lying on the sandy ground, the nurse sharks have not yet noticed their observers. “Between March and June, we can see up to eight per dive. We think that these sharks, which normally live deeper, go up to 15 meters to reproduce, because the waters are warmer there. But for now, this is just a hypothesis,” explains Thibaut Molina, co-founder of the ScubaTek diving school in Arue, a town in eastern Tahiti. His school has formed a partnership with the Institute for Research on Mesophotic and Deep Ecosystems, led by independent researcher Clémentine Séguigne, to develop research and awareness around sharks in Polynesia. In this context, they organize dives to meet them, during which the researchers collect the data.
Suddenly, the youngest shark runs away. Its large triangular tail swirls a thick cloud of sand. The group freezes. “When divers come, we often get this question: ‘Are we going to see sharks?’ With a tone that mixes apprehension and excitement,” smiles Thibaut Molina, who insists on the importance of protecting sharks in Polynesia, as everywhere else.
Diving, or just swimming, in French Polynesia is always an opportunity to encounter them: whether they are small, like those of the reef, or several meters long, like the lemon sharks. In 2006, Polynesia classified its waters as a nature reserve for all species of rays and sharks, with the exception of the mako, which was commercialized at the time. At the request of many environmental associations, it was finally protected six years later. At a time when overfishing is wreaking havoc (37% of shark and ray species are threatened with extinction, according to the IUCN), French Polynesia wants to set an example and protect these species from their massacre and commercialization.
A beneficial reserve?
In parallel with the establishment of the reserve, a network of divers developed the French Polynesia Shark Observatory across its five archipelagos. The goal: to report shark observations made during dives. Species, size, area, date… Everything is recorded in a large database available online. Clémentine Séguigne analyzed the information collected from 2011 to 2018 as part of her thesis carried out at the Moorea Island Research Center and Environmental Observatory. It is one of the rare studies that exist on the effects of the reserve.
“We were able to see that there was a very significant diversity of species. There was also, in certain places, an abundance of these – like the hammerhead shark in Rangiroa and Tikehau, for example – species that are today considered endangered,” explains Clémentine Séguigne. The scientist believes that these results are encouraging, but that they must be confirmed by more in-depth studies, the method used by diving centers suffers from bias and a lack of rigor. “Even if we have some positive points about the reserve, like the ban on fishing for sharks, we know that it can be optimized,” continues the specialist.
The protection of the 20 species does not prevent depredation. As a recent study pointed out, about 20,000 sharks die each year in Polynesian waters after being accidentally caught in nets. This number excludes non-accidental catches. In recent years, some fishing boats, most of them international, have been prosecuted for fishing sharks in French Polynesia.
Sacred animals
In ancient Polynesian culture, sharks are sacred animals that represent gods and ancestors, the links between the living and the dead. “Our myths speak of sharks as guardians of our families, but also navigators. Our ancestors observed them to find the different islands,” says Matahi Tutavae, a specialist in Polynesian culture and the environment. Are these traditions and beliefs disappearing? According to Clémentine Séguigne, fear of sharks has increased with the Westernization of society. In one of her recent studies, half of the 300 residents surveyed said they thought sharks were potentially dangerous. However, in recent years, few accidents have been recorded.
The specialist’s research also indicates that the rules of the reserve sometimes remain misunderstood, or even poorly known, especially in the islands furthest from Tahiti. This reserve can also be a source of conflict. “The reserve is a very good thing, but at the same time, there has been no discussion with the local population about the rules and measures that it implies,” observes Siméon Wong Sang, a fisherman in Rangiroa, an atoll in the Tuamotu archipelago, north of Tahiti. On our island, there are many sharks and it is becoming increasingly difficult to coexist with them. The sharks are there all the time and they eat our fish…” He estimates that around ten sharks are killed each year by fishermen in these conditions.
Clémentine Séguigne and other researchers are working on different projects to improve cohabitation between fishermen and sharks in certain Tuamotu islands, among others, where fishing is a means of subsistence for many families, so that everyone can live in harmony in this haven of peace.