Preserving white sea cucumbers in Tahiti: when traditional knowledge becomes pivotal for a scientific project

The white sea cucumber “rori titi u’o” (Holothuria fuscogilva) is a species highly prized in Asia for its meat and medicinal properties, so much so that its high commercial value has led to its overexploitation in the Indo-Pacific region.

BEST 2.0+ was very excited to award the civil aquaculture company “Tahiti Marine Products” with a grant in July 2021 to implement the “Vairao Rori Titi project”, an endeavour devised to contribute to preserving and managing this species for its sustainable exploitation in French Polynesia by undertaking stock surveys and searching for juvenile habitats.

In May 2022, once come to a close, the BEST2.0+ Secretariat had the opportunity to visit the project site, the Vairao lagoon, on the southwest coast of Tahiti, and exchange with those involved in it.

Mahanatea Garbutt, a passionate and committed Tahitian marine biologist and an aquaculture technician, engaged in a riveting chat with us. What follows below are some snippets of the conversation we had with her.

1- In your opinion, what are the key challenges around conservation in French Polynesia?

I think the main challenge in terms of conservation is that many families still depend on daily fishing. This can sometimes make it difficult to set up and enforce regulations.

In the past, fisheries regulations were very often governed by ‘ the elders’, who were experienced and authoritative, and who were respected. Nowadays, however, the knowledge of these wise men is no longer considered, and people fish as much as possible to sell as much as possible.

Although it is not an obvious job, there is still much that can be improved in terms of legislation for the conservation of our natural resources (e.g. legal size of fish in lagoons, etc.).

2. How are local communities in French Polynesia affected by these challenges? Are they involved in conservation efforts?

Scientists and/or biologists neglect too frequently the opinion of the local population, especially the fishermen of the area. I find scientists as being sometimes too confident and reliant on the scientific papers they read, instead of learning from the experience and the knowledge of the inhabitants of the area. From my point of view, conservation and preservation of the local resources can be more effective and perennial if the inhabitants are actively involved in the decision-making process and are responsible for the management of these resources. As general rule, Polynesians are aware of their environment and the importance of its protection. However, they also rely on marine resources for food. As a result, some drastic conservation rules might not be obeyed, e.g. as can be the case of local fishermen, since they also need to “put food on the table”. 

When a conservation project is created, first, a relationship of trust in the traditional knowledge of the local inhabitants should be factored in if we want the project to be successful and respected. 

3. What are your organisation’s key priorities and activities around conservation in French Polynesia? 

The Vairao Rori Titi project focuses on a “vulnerable species” (Annexe II of the CITES), the white teat fish sea cucumber (Holothuria fuscogilva). Fishing activities of this species were first regulated in 2012 before being completely banned in 2019. In French Polynesia, almost no research and studies have been done on this species, as they were usually carried out on sea cucumbers. Therefore, we do not have a database on their type of habitats, their migration activities during their lifecycle, etc. However, to protect a species efficiently, we first must understand its interaction with its environment. 

4. How does Vairao Rori Titi fit in this context? Why pursue this project?

The BEST 2.0+ project came as an opportunity to study and learn more about this species. The Vairao Rori Titi project has been beneficial in finding and defining “hotspots” where those sea cucumbers gathered. We also tried to analyse the common traits of each site, such as the depth, the type of sediment, etc. 

Several study opportunities have arisen from this study. There is still much to do and study in our lagoons and, in particular, on the migration of this species, the preferential areas of recruitment of larvae, juveniles, young adults, etc. and their food preference, e.g., does he prefer a certain depth? Why?, etc.

5. How has this project engaged and incorporated the local and traditional knowledge into its planning and implementation?

From the beginning of the project, former fishers were sourced for their knowledge of the areas where they had previously observed and fished sea cucumbers. We worked together to define the sites and adapt the protocol initially proposed by The Pacific Community (SPC) to the characteristics of the Vairao lagoon. We modified the initial protocol and, instead of diving only once in an area, we adapted the dives to the lunar phase as fishers had noticed sea cucumbers are more abundant in one site than in others depending on the moon phase. Thus, we dove on each site weekly according to the moon phase. Indeed, we did notice a difference in the number of sea cucumbers over the weeks from site to site. Unfortunately, the results were not enough to be statistically significant. Nevertheless, those observations made sense with what the fishermen have been explaining to us from the start. 

6. What have been the most notable achievements and examples of impact of your project?

Thanks to this project, 1) we have listed ten sites within the lagoon of Vairao where white teat fish are continuously present;  2) we have built a database of each white teat fish encountered (length, width, photography); 3) we have trained Scuba divers to recognise the sea cucumber and the type of substrate preferred by the animal; 4) we have plotted the seagrasses beds and seaweed beds (favourite habitats for juveniles according to scientific papers) found in the lagoon of Vairao, and 5) we can advise on the more appropriate stock assessment technique (scuba, free divers or ROV) to use according to the features of the chosen area.

Even though the statistical tests have not been conclusive due to lack of data, this project helped us understand the animal trend and will help us decide on a future efficient conservation plan. 

7. What would you like to happen next in the context of this project?

As a project manager, a marine biologist and an aquaculture technician, I became very passionate about this animal, and I am still wondering what their actual migratory behaviours are during their lifecycle. As we have not found any juveniles in the wild, we currently don’t know where they go during their larval stages and their juvenile and sub-adult phases. This information will help us with its overall conservation, preservation and aquaculture practices.

8. How has the collaboration with BEST played a role in your organisation’s work?

Working in collaboration with BEST has trained us to manage our budget correctly and be clear and determined about the results we want to achieve. Therefore, the planning had to be sound thought-out, and we had to anticipate any possible change. 


If you want to see some inspiring footage of the work done underwater by this project, take a look at this video!