Tara: discovering sponge treasures in Wallis and Futuna

© Jonathan Lancelot / Tara Expeditions Fondation

The archipelago of Wallis and Futuna is a French overseas collectivity located in the heart of the South Pacific Ocean. Its seabed teems with life that’s been only partially researched. A brief inventory was made in 1990. When the Tara Pacific expedition went there, its scientific mission was extended beyond corals, to identify all the underwater species present. Some belong to a group of marine organisms that are among the oldest animals on our planet and contain biological secrets: sponges.

A great diversity of sponges is synonymous with complex chemicals

Coral reefs look like peaceful environments teeming with life, but they can be sites of silent wars among their inhabitants. Wars, for example, between corals and sponges. Sponges secrete particularly potent chemicals because it’s their only means of defense, unlike corals which have very resistant skeletons.

Ascidies_vertes_et_rose_sur_eponge_agelas@JLancelotGreen and pink Ascidians grown on sponges © Jonathan Lancelot / Tara Océan Foundation

Sponges are invertebrates that settle everywhere in the ocean. During the course of evolution, they demonstrated very great adaptability that allowed them to survive and colonize a whole range of different environments. For the last 40 years, their chemical arsenal, known as one of the most aggressive, has aroused great interest among scientists, particularly in the field of human health. Some active molecules produced by sponges are already used in anticancer, antiviral or antibiotic treatments.

Because of its geographical isolation, the archipelago of Wallis and Futuna remains little-known and the most recent inventories of marine diversity have long remained incomplete. It has recently been discovered that sponge biodiversity specific to this ecosystem could hold potential promise.

Updating the biodiversity and potential of the Wallis and Futuna archipelago

For the Tara Foundation, exploration of the Wallis and Futuna coral reefs was one of the most reassuring and promising stages of the Tara Pacific expedition. Unlike many other extremely damaged and largely bleached coral ecosystems, the Futuna Reef, visited in December 2016, was in very good health. Marine organisms were both extremely diverse and abundant. This was reassuring because the survival of local populations on these remote islands depends largely on the reef’s state of health.

Tara dans le lagon de Wallis, entre deux sites de prélèvements Tara is on the Wallis Lagoon, between two sampling sites © Pierre de Parscau / Tara Océan Foundation

Tara’s exploration of the Futuna reefs was a special opportunity to make an accurate inventory of the reef fauna. Thanks to more than 2 weeks of intensive sampling around the archipelago, the Tara team was able to update the catalogue of marine species around the islands, including sponges. A large number of sponge species were inventoried — some rare, perhaps even endemic and completely new. This represents a potential for valorisation of substances secreted by these new species of sponges – a potential that the local populations of the Wallis and Futuna Islands may or may not choose to exploit.

During their stay on the remote archipelago, the Tara Foundation team worked closely with the kings and their communities. Tara scientists submitted their observations and discoveries to the indigenous people for their decision on the right steps to take for the future of their islands. If the local authorities decide to encourage further research on the sponges’ active molecules, pharmacological applications might be discovered, and part of the profits from these would automatically accrue to the inhabitants of the archipelago, as stipulated in the UN Convention on Biological Diversity.

TARA: THE KING’S ARCHIPELAGO
(French Only)

A 52-minute documentary.
A scientific adventure in the unique and little-known biodiversity of the Wallis and Futuna archipelago.
A film written and directed by Pierre de Parscau, narrated by Jacques Gamblin, produced by The Cup of Tea, co-produced with the Tara Foundation, with participation of France Télévisions and the CNC.

TARA L’ARCHIPEL DES ROIS

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