Do corals resist heat from volcanic activity?

© Vincent Hilaire - Tara Expeditions Foundation

16 November 2017

Tuesday, November 14 at 15:30 local time Tara arrived a few kilometers from Kimbe, capital of the province of Western New Britain. Along the northern coast of this island of Papua New Guinea, we completed the last few miles with no wind and the help of Tara’s engines.

Simon Rigal, Tara’s captain since Whangarei (New Zealand) will disembark here, handing over the helm to Samuel Audrain.

 Kimbe Bay — 110 km wide and 60km long — is considered the heart of the Coral Triangle. The scientific team, led by Rebecca Vega Thurber (from Oregon State University), has planned 3 new sampling sites.


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Islands on the way to Kimbe © Vincent Hilaire – Tara Expeditions Foundation


A succession of volcanoes, some still activeislands like boats with hulls of lava rock above which flourishes lush, tropical vegetation. During the last hours of sailing, the landscape kept telling us we were getting closer to the equator and Indonesia. Anchored tonight in a sheltered spot, Tara is only about 5 degrees south of the line separating our blue planet into 2 hemispheres.

We are not here by chance: Kimbe Bay is a major site for biodiversity: it alone includes 60% of the coral species present in the Indo-Pacific area. This heart of the Coral Triangle is also the place of origin of all corals. According to Alfred Yohang Ko’ou, our Papuan scientific observer (soon to disembark) “This is the cradle, the first nest of all Pacific corals. Ocean currents did the rest by scattering the mother stock.”

A first scouting and sampling dive has already taken place at the entrance to Kimbe Bay. It confirmed the extraordinary biodiversity and health of coral polyps in these very warm waters, averaging around 30° C. Another question of particular interest to the researchers on board here: Why doesn’t the coral undergo bleaching in such warm waters? Will Kimbe Bay corals offer us new elements to better understand why these colonies are resistant to such temperatures, linked to intense surrounding volcanic activity?


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Papua New Guinea: the country of volcanos and corals © Vincent Hilaire – Tara Expeditions Foundation


We are in a region with more than a hundred volcanoes visible from the boat. We’ve had the chance to sail safely by them, including the most destructive ones, Vulcan and Tavurvur, close to the new Rabaul. Fumaroles are still escaping from the Vulcan caldera, with the strong smell of sulfur. History reminds us that these partly dormant giants literally engulfed the old Rabaul in 1994  a Papuan Pompeii still buried under the now solidified lava.

Here coral lives in waters whose temperatures are influenced by a volcanic environment where thermal stresses combine. The upcoming dives in the context of the Tara Pacific expedition promise to be very exciting.


Vincent Hilaire


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