The Coral Triangle: birthplace of all coral colonies on the planet

© Vincent Hilaire - Tara Expeditions Foundation

Before heading towards Papua New Guinea, Dr Rebecca Vega Thurber, a biologist at Oregon State University and scientific coordinator of this mission, makes an initial assessment of the dives carried out in the Solomon Islands’ waters.


Rebecca, what did you expect before diving here? In sampling the Solomon Islands, Tara Pacific just entered the Coral Triangle.It’s worth repeating that the Coral Triangle host 30% of all coral reefs.

“As you’ve just reminded us, the Coral Triangle is recognized for its very rich biodiversity and exceptional coral cover. Before these first dives, I expected to discover the heart of the global coral system and the most beautiful reefs in the world. I was not disappointed. Quite the contrary! And, as a microbiologist, I’ve seen many reefs and colonies!” (smiles)
photo3_Acropora Pink_VH
Pink acropora © Vincent Hilaire – Fondation Tara Expéditions


What words would you use to describe what you saw underwater?

“I was dazzled. This exceeded all my expectations: there were coral species I had ever seen and an extremely dense coral cover. I witnessed a 3D structure with all possible types of colonies at all stages of their life cycle.

These impressions are especially true for the first site, where I was absolutely amazed by fish sizes, the variety of species and their shape. This first site was incredibly rich: fish, corals everywhere. This shows how healthy these colonies are.

The second site was also striking with drop-offs covered with amazing coral and extraordinary biodiversity. I didn’t have enough bags underwater to collect all the coral species (laughs). At the third site, we saw a different situation. It was still very nice but there were many macro algae. This shows that this ecosystem is already imbalanced. When you see too many algae like these, it means fish won’t eat them. The cause often lies in overfishing and/or water pollution.”


photo 20_Rebecca Vega Thurber prend photo futur echantillon_VH
Rebecca Vega Thurber takes a photograph of a future coral sample © Vincent Hilaire – Tara Expeditions Foundation


Do you have an idea of the number of coral species you’ve seen in the Solomon Islands’ waters?

“There were many species I saw for the first time in my life.” Sometimes, in one place underwater, I saw 25 different sizes of 24 species. As a result I’d say, but without making a count, that we’ve seen about 450 different species between these 3 sites.”


Without anticipating future results after collecting all these samples here, how do you explain the general good health in the Coral Triangle?

“Many past evolutions took place in the Coral Triangle. It can be compared to Africa for humanity. It’s the cradle of all coral colonies on the planet. These first corals spread from there to all regions of the world. They are pre-adapted to shallow waters, where there is plenty of sunlight and high temperatures. They may have already evolved and adapted to the new extreme conditions prevailing in the oceans.


photo 21_clown fish 4_VH
Two clown fishes in an anemone, a very stinging plant for other species © Vincent Hilaire – Tara Expeditions Foundation


The great diversity of fish species helps corals to be resilient to climate changes. They work together as a community. When a reef loses its diversity, it also loses its ability to withstand and buffer environmental disruptions.
Over the last 3 years, there have been bleaching events throughout the world and these reefs here are not immune. With increasing pressure from human activities through over-fishing and logging for example, the Solomon Islands may be the next victims on the list.”


Vincent Hilaire

Articles associés