Rapa Nui: An Oasis for Marine Turtles

Authors: Rocío Álvarez Varas, Camila González Johannes, Michel García Baral

A vital habitat for marine turtles in the Pacific

Rapa Nui is one of the few places in the South Pacific where two endangered marine turtle species live together in a stable feeding habitat, making the island a key site for their conservation. Marine turtles are migratory animals which live in all the oceans of the world, with the exceptions of the Arctic and Antarctic. Within their life cycle, they occupy two types of habitat that are often very distant from each other: the breeding habitat and the feeding grounds. Breeding habitats are usually found in areas within the tropics where the temperature of the water and sand is higher, thus assuring more successful development of the eggs. In these areas, turtles mate near the shore so that the female can go onto the beach to lay her eggs, where they will incubate in the sand for approximately two months, at which time the hatchlings emerge and quickly head to the sea.

The turtle life cycle: migration and threats

Young turtles can spend many years in the ocean, moving about on the great oceanic currents, before establishing themselves in coastal areas to feed and grow. These areas, called feeding grounds, are usually found in cooler waters where there is a larger amount of food and areas of refuge. The turtles may stay in these areas for more than 30 years, therefore their protection is essential for the conservation of the species. The long migrations between the two habitat zones expose the animals to a variety of threats from humans. Some of the principal dangers are the risk of interaction and death in fishing nets, collisions with ships, the consumption of turtle meat or turtle eggs by humans, contamination of the sea by plastics, the destruction or alteration of their breeding or feeding grounds and, in the case of the Carey turtle, the use of their shells in crafts and jewelry.

Rapa Nui, an oasis for marine turtles in the middle of the Pacific

Rapa Nui is an oasis in the middle of the Pacific Ocean and a feeding habitat for marine turtles. The most commonly found species are the Green turtle (Chelonia mydas) and the Carey, or Hawksbill, turtle (Eretmochelys imbricata), both in danger of extinction. As on other islands of Polynesia and the Pacific, marine turtles have been an important part of the cultural identity of the Rapanui people since ancient times, showing up in the art, mythology, symbolism, popular traditions and in ritual and spiritual life. Their presence in petroglyphs throughout the Island, as well as on the wooden Rongo-rongo boards and in creation legends, indicate the importance that the Rapanui people attached to these animals since the arrival of the first inhabitants. Even so, and even to the present day, their origins, patterns of movement, diet and other aspects of the life of these species are unknown, much like other marine species found in the deep waters surrounding the island.

The marine turtle monitoring program on Easter Island

In 2012, the ORCA Diving Center, together with Rocío Álvarez-Varas of the University of Chile, began developing a non-invasive marine turtle monitoring program. The program, based on photo-identification, uses facial photographs of both cheeks to identify each individual and track them over time. To date, they have recorded at least 27 individual Green turtles of different sexes and sizes (juveniles and adults), belonging to two distinct types, 20 yellow and 7 black. All Carey turtles photographed have turned out to be juveniles. Their time on the Island varies: some have been photographed only once, while several are considered resident and have been observed for more than six years. The continued presence of some of the individuals confirms the importance of Rapa Nui as a feeding ground for marine turtles in the middle of the vast Pacific Ocean. Preliminary data indicates the importance of future studies on these endangered species and this isolated habitat in the South Pacific. In the meantime, the project is offering talks and workshops in the schools, with groups of divers and with groups of the Rapanui community to inform them on the results to date of the marine turtle monitoring program and to encourage local participation in the conservation of these animals.

Where to see marine turtles in Rapa Nui

To see the turtles, visitors should head to the bays of Hanga Roa or Hanga Piko. Here they come close to shore to feed, especially on the algae on the rocks. With luck, diving with the island’s specialized turtle diving center a diver might encounter a Carey turtle among the coral reefs, the same seabed where octopus and squid native to the Pacific also live. During your visit, please remember to leave your rubbish in appropriate places and don’t feed the turtles or other sea animals. Take care of the sea and respect all of its biodiversity. Don’t forget that it is part of our natural heritage.

Frequently asked questions about marine turtles in Rapa Nui