Magnificent, unsettling, impressive, breathtaking… Such are the adjectives that come to mind when you cross paths with The Manta Rays under water. But this giant and mythical fish is now getting rare in our lagoons as they are more and more disturbed by human activities. In Bora Bora, the famous kingdom of these threatened Queens, an Association is fighting for their cause.
How can anyone forget the small fixed and inquisitive eye of a manta ray trying to make eye contact with you? Or the aquatic ballet of a group of these giants, swimming to meet you in a intimate and shy exchange? These magic moments are perceived by any diver as precious presents, moments of plenitude suspended between two waters. Manta rays belong to the big family of rays, a lineage supposedly issued from the adaptation of the shark to the scarcity of halieutic food, in the tertiary era, some 60 millions years ago. Over five hundred species have been counted throughout the world, divided in eighteen thousand families, all of them different by their shape, their territory and their lifestyle. The manta birostris ray, of the Mobulidae family, the only species encountered in Polynesian waters, is the most impressive among them. It can reach up to 6 meters and weigh over a ton. Its atypical morphology is constituted of a head part of a flat body shaped like a wider than long lozenge with supple and pointed fins giving it a winged and elegant silhouette. Their back is dark brown to black and their white belly has dark spots, whose unique disposition is the mark of distinction of individuals. It is its unique shape that gave it the name of “manta” (“blanket in Spanish). The manta ray is a voracious plankton and small nektonic animal (small fish) that it swallows with its wide-open mouth. It cannot stop swimming, otherwise it would sink and choke. So it swims at night over long distances, 10 to 20 kilometers to feed. In the morning it looks for the sun and shallow waters to warm up its back and speed up plankton fermentation in its stomach, thus facilitating its digestion.
A Mythical And Threatened Animal
Is it its “horned” appearance, with its two cephalic lobes guiding the plankton toward its wide-open mouth, that caused it to be called “devil of the sea” on all the oceans of the world, or is it its impressive size? All over the world, it has inspired many legends and mythologies that demonize it. The manta ray has indeed for a long time been feared by sailors and fishermen who were afraid it might pull their boat to the bottom of the ocean. In French Polynesia, it is said that it prevented pearl fishermen divers without scuba equipment to get back to the surface by covering them with its impressive body. In the Tuamotu, some legends even accuse it of kidnapping and rays with children heads are part of the islands’ oral tradition. Today, the Polynesians still fear them when they are under water. However, its food based on plankton and its inquisitive and peaceful behavior makes it a truly harmless fish. No verified facts or recent testimonies support any of these myths.
While the manta ray is no danger to man, the reverse is unfortunately not true: today it is really the manta ray that is threatened by man. In Asia, it is fished for the leather of its skin and for Chinese traditional medicine, and the demand for fins and gills has expanded its fishing zones to Africa and Mexico. In other countries of the world with tropical and subtropical reef zones (Australia, Hawaii, Maldives, French Polynesia), it suffers from its own popularity, which made it one of the most sought after animal in terms of observation. The respective governments are thus little by little forced to take measures to reduce tourism pressure, which is harmful to the species’ tranquility. Thus the Manta Birostris is now classified as “nearly threatened” (NT) on the red list of IUCN (International Union for the Conservation of Nature). Since 1998 in French Polynesia, the capture, removal, destruction, pick-up, transportation, sale, use and marketing of all or part of a manta ray is strictly forbidden. Although it is the only fish protected since February 2008, by its inscription in class A of threatened Polynesian species (there are 165 of them), the manta ray, the only protected fish, still does not always benefit from concrete measures to protect its environment.
Bora Bora, The Stakes Of Biodiversity
Manta rays are found in the five Polynesian archipelagos (except Tahiti and Moorea), but divers come to observe them mostly in Bora Bora, in the passes of the Tuamotu Islands (Rangiroa, Tikehau, Fakarava) and in the Marquesas. Bora Bora, through its tourism activity (an average of over 40,000 tourists per year) and the riches of its lagoon, is a typical island where danger threatens its manta birostris. It is indeed through the observation of the evolution of their population in function of human activity in this mythical lagoon, that the stakes of their protection take full meaning. Since 2002, Moeava de Rosemont, diver, cameraman and Vice-President of the Manta Polynesia Research & Protect Association, has completed a photographic identification in order to evaluate the population of the island’s lagoon. He has observed that the presence of manta rays on the three main sites of Toopua, the Pass and Anau, is directly linked to tourism activity and to construction work (hotels and private landfills) taking place there. Thus, the Toopua site has almost been deserted since the construction of a hotel in 2002-2003. The Anau site is still the most popular. Frequented as much by passing sailboats as it is by tourism professionals, Anau is a regrouping site during the reproduction period, and a cleaning station for labrum fishes that remove the rays’ parasites. They are easier to approach and therefore often disturbed by divers. In June 2005, the Association observed the abandonment of the Anau site by the manta rays, likely due to too strong a human pressure generated by tourism development and the construction of two hotels near the site.
Since 2009, due to economic slowdown and the drop in tourist frequentation, the manta rays slowly came back to the area. In 2010, only twenty resident animals are supposedly remaining in Bora Bora (versus over a hundred at the end of the 80’s). Their protection has therefore become an ecological and an economic stake. Today, the future of these friendly “devils” in our lagoons depends on concrete actions to protect their environment. The Manta Polynesia Research & Protect Association, which since 2004 militates for a protected marine area (AMP) in the Anau area, is not without ideas on the subject: “We recommend the implementation of sworn lagoon guards, speaking French, English and Tahitian, in charge of raising awareness and to fine offenders if necessary. Financing could be done through the sale of mother of pearl tokens, symbolizing an environmental tax” explains its Vice-President. Thus only a general mobilization supported by firm political implications, would be able to slow down the manta ray’s departure and would offer a kingdom worth of their majesty to these fragile Queens.