23 November 2015

Hydrothermal Hunt at Mariana

Posted by lhwang

This is the first in a series of dispatches from scientists and education officers aboard the Schmidt Ocean Institute’s R/V Falkor. This November, scientists aboard the research vessel Falkor will aim to shed light on the Mariana back-arc, which is expected to be teeming with activity and life. Over the course of their 27 day mission at sea they will explore the back-arc spreading center to find new sites of hydrothermal activity and to better understand the physical, chemical, and geological forces that shape biodiversity in these unique ecosystems. Read more posts here, and track the Falkor’s progress here.

A map of the planned survey area for the Hydrothermal Hunt at Mariana expedition.

A map of the planned survey area for the Hydrothermal Hunt at Mariana expedition.

Though most famous as the home of the deepest spot on the planet, the Mariana subduction system is also an valuable natural laboratory for testing ideas about what governs the distribution of animals at hydrothermal vent systems. That’s because the area has a wide range of habitats, including the very deep trench, a shallow to mid-depth volcanic arc, and a mid-depth to deep spreading back-arc. Of these, only the volcanic arc has been the focus of extensive hydrothermal vent exploration and research, resulting in the discovery of 20 hydro-thermally active seamounts and over 20 new species. In contrast, more than 600 kilometers of the Mariana back-arc remain completely unexplored. That will be the focus of this expedition.

The work will involve two main components. First, the team will use an Autonomous Underwater Vehicle (AUV) and other techniques to locate and characterize hydrothermal systems, expecting to find 5 to 10 new sites. They will then return with a remotely operated vehicle (ROV), to study the vents discovered. One basic goal will be to catalog the life forms found at these vents, their affinities, and their relation to the regional biogeography. There are likely to be some surprises given how little exploration has been done on the back-arc. Working at the handful of back-arc sites previously studied, for instance, researchers found huge hairy snails never before seen. The team will also be examining the chemistry and geology of the vents, studying their microbiology, and testing ideas to explain the substantial biological differences between the volcanic arc and back-arc vents.

– Courtesy of Schmidt Ocean Institute. View the original mission summary here.