Every year, from July to November, humpback whales (megaptera novaeangliae) migrate from the icy waters of the Antarctic where they feed to the warm waters of the shores of Tahiti and her islands. It is the ideal place to give birth and breed, sheltered from their predators. The adults measure between 15 to 18 meters (40 to 60 feet). They look very graceful while moving their huge pectoral fins under the water. The calfs measure about 4.50 meters (15 feet) at birth. They can put on up to 100 kg per day during the first week of life, whale’s milk is the highest fat content of the animal kingdom. As a cetacean (whale) sanctuary since May 2002, all whales of French Polynesia are protected. Whale watching complies with strict local regulations.
Although they can be watched around any island, Rurutu is a good location to encounter them. You should have an experienced guide who holds an official government authorization. They will help you encounter and enjoy theses giants of the ocean.
Bubbles are a sign of aggressiveness to marine mammals. Scuba diving is therefore not the best way to encounter them. You are likely to experience a once in a lifetime encounter with only your snorkeling gear. For you and the whales’ safety always follow your guide’s instructions when you are in their presence.
As a cetacean sanctuary, the dozen dolphin species of French Polynesia are also protected. They are present year round and can be seen around any of the islands. Dolphins have very similar behavior to humans. They give birth, nurse their calves and breathe air. Their communication skills are very sophisticated. There is no doubt to encounter some of them during your stay in Tahiti and her islands. Three main species are easily watched depending on the areas: bottle nose dolphins (tursiops truncatus), spinner dolphins (stenella longirostris) and rough toothed dolphins (steno bredanensis).
Out of the 350 species known worldwide, 19 of them can be observed in the waters of French Polynesia. It is a perfect place for any diver to encounter them. It is also the ideal place to demystify their negative misleading public image. The most commonly encountered species in Tahiti and her islands are the famous black tip sharks (carcharhinus melanopterus – Tahitian name: ma'o mauri), grey sharks (carcharhinus amblyrhynchos – Tahitian name: raira), lemon sharks (negaprion acutidens, Tahitian name: arava) and hammer head sharks (sphyrna lewini or sphyrna mokarran – Tahitian name: ma'o tuamata).
Since Antiquity and up to now, the western world views sharks as bloodthirsty animals. Yet, the ancient ma’ohi lived with them in harmony. Sharks represented a protective icon in which the kind spirit of a family ancestor was reincarnated.
Sharks belong at the top of the food chain and are generally either predators (population controllers) or scavengers and cleaners. They play an essential role in regulation and balance of the marine eco-systems. Thought to have evolved about 400 million years ago, these fish are extremely well. Developed and perfectly adapted to their environment. Having had no predator for millions of years, the rate of breeding is slow and quite inefficient. Depending on the species, a female’s gestation can take 4 to 24 months with a potential fertilization only taking place every couple of years.
Over fishing, pollution, killing sharks for their fins represent some of the many threats factors threatening and endangering sharks. According to scientific data, it is believed that over 150 million sharks are killed each year. Some species are already nearly extinct. For this reason French Polynesia made the decision to protect them by law in 2006.
Two main turtle species live in French Polynesia and are easily encountered in some dive spots. The green turtle (chelonia mydas) owes its name to the color of its flesh and fat. The female reaches sexual maturity between 15 and 20 years of age. She can measure 1.50 meters (60 inches) and weigh up to 200 kg. The juveniles are carnivorous but become herbivorous once they become adults. The hawksbill turtle (eretmochelys imbricata) is smaller and does not measure more than 90 cm (35 inches) for a weight of 90kg. Carnivorous, they are often found searching for small sponges stuck under rocks. They move using these rocks using their frontal legs. Oviparian, they have a slow reproduction cycle and a late sexual maturity. There are less and less laying sites due to loss of habitat from human development and they are the victims of drift net fishing and hunting. Turtles are now in danger of extinction worldwide. Numerous consciousness-raising campaigns are promoted in Tahiti and her islands to ensure their conservation.
Belonging to the elasmobranch family, rays are close cousins to the sharks. They appeared about 150 million years ago. Like the sharks, they have a cartilaginous skeleton. Yet, they are quite different: their brachial slits are located on the belly and their oversized pectoral fins are welded to their head enabling propulsion. This is what makes them look so gracious, looking like underwater birds. Like their cousins, they have two sexual appendices called pterygopods. Three species of rays can be found easily in Tahiti and her islands: sting rays (himantura fai – Tahitian name: fai i'u), eagle rays (aétobaus narinar – Tahitian name: faimanu) and manta rays (manta birostris – Tahitian name : fafapiti). A couple of other manta species may also be seen: himantura sp. In theMarquesas and mobula tarapacana, a pelagic kind of manta ray bound to be encountered in the Tuamotu, Gambier and Marquesas.