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Gorgonian (sea fan) corals on the twilight reefs of Pohnpei Island. (credit: Sonia J. Rowley)

Sonia J. Rowley, post-doctoral research fellow at the University of Hawaiʻi at Mānoa School of Ocean and Earth Science and Technology, received the prestigious Sir David Attenborough Award for Fieldwork from the Systematics Association and the Linnean Society of London. Rowley’s work was selected based on her project entitled “Exploration and Systematics of Twilight Reef Gorgonian Corals at Pakin Atoll.” She is only the third person to receive this award, which was given to her for her work during the 2015 Pohnpei Expedition.

Tropical coral reefs throughout the Indo-Pacific are critical to marine biodiversity. About 80% of reefs exist between depths of 100-500 feet and are among the most diverse, yet most unexplored, realms on the planet. These ‘twilight zone’ reefs, known as Mesophotic coral ecosystems or MCEs, are typically dominated by gorgonian (sea fan) corals.

New technology enables new discoveries

Sonia J. Rowley

The mysteries of these twilight reefs are only recently being revealed through technological advances in closed circuit rebreather diving. Previously overlooked—being too precarious for conventional SCUBA and too shallow to justify the cost of frequent submersible dives—twilight reefs continuously disclose breathtaking levels of biodiversity with each dive, yielding species and behavioral interactions new to science. Further, MCEs are classified as conservation priority ecosystems and posited to act as refugia against environmental disturbances.

The primary aim of the Pohnpei field project was to explore and describe gorgonian corals on the unexplored deep-reefs of Pakin Atoll using technological advances in electronically controlled rebreathers, data digitization and dissemination.

A lifetime of training

“I was raised on commercial diving vessels in the UK and I am now a test pilot for Poseidon/CisLunar rebreather technology,” said Rowley. “It’s amazing to combine this advanced technology with marine science and biology. Ultimately, I want to know what things are, what they do, and how this came about relative to the environment over geological time. This involves continuously pursuing a suite of technological techniques to address various research questions, which essentially provide information to how deep gorgonian corals have been so biologically successful over time. In addition, this type of research has and continues to benefit local communities.”

Bringing the ‘twilight zone’ to light

Rebreather dive team, from left, Richard Pyle, Sonia Rowley and Brian Greene. (credit: K. Kaing.)

In collaboration with the Waikīkī Aquarium, Rowley and others are developing ways to re-create conditions that closely match the twilight reef environment. Through continuous measurements of key parameters, they are working to create a natural exhibit of gorgonian coral and increase understanding of adaptations that have evolved over time. Rowley recently shared her findings from the twilight zone in a public presentation through the Waikīkī Aquarium Distinguished Lecture Series.

Rowley has been at UH Mānoa since 2010, first as a visiting scholar and then as a post-doctoral fellow with Steve Stanley. She received her doctoral degree from Victoria University of Wellington, New Zealand and bachelor of science at the University of Plymouth, United Kingdom.

For more information on Rowley’s annual expedition to Pohnpei and its atolls including research experimentation, collaboration and community involvement visit the Association for Marine Exploration Expedition blogs page.

—By Marcie Grabowski

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