The mysterious world of deep, Gorgonian corals
Sonia Rowley practicing her experiment in the shallows of 30 meters. Photo Credit: Marla Tomorug.
Sonia Rowley, an assistant researcher in the Department of Earth Sciences, was featured in an article on SHE Changes Climate. Excerpts of the profile article are below.
* * * *
An Expedition to Waikiki, Hawai’i
The exploration of our planet’s oceans often reveals extraordinary creatures that serve as key indicators of our climate’s health. Gorgonians—commonly known as “sea fans”—are not just fascinating for their size and structure but also for their critical role in marine ecosystems. With over 1,200 species documented, gorgonians are a vital part of coral reef systems, making up 64% of all corals on earth. These corals contribute significantly to the biodiversity and stability of underwater environments, many of which are increasingly threatened by climate change.
Gorgonians belong to the Octocorallia class, characterized by their unique eight-fold symmetry and the protein gorgonin, which gives them flexibility and resilience in their deep-sea habitats. These corals have adapted over millions of years to thrive at depths where sunlight barely penetrates, with 75% of them found at 50 meters (164 feet) or deeper. However, rising ocean temperatures and acidification—consequences of climate change—pose significant risks to these ancient marine organisms, among many other human-induced actions.
Our understanding of gorgonians and their ecological importance has been greatly expanded by experts such as Dr. Sonia J. Rowley, a professor at the University of Hawaiʻi. Dr. Rowley is one of the few researchers who have ventured to depths of 181 meters (600 feet) to study these corals firsthand. Her work provides invaluable insights into these deep-sea creatures and highlights the broader impacts of environmental changes on marine life, emphasizing the need for dedicated conservation efforts backed by science. And in this case, deep-sea science.
Sonia’s Beginnings
Hailing from a small fishing village in England, Sonia’s formative years unfolded on the deck of a boat, far removed from the conventional classroom setting. Despite the challenges of dyslexia that hindered her in her youth, she found solace and a sense of belonging in the ocean, learning to dive by the time she turned 11. This is where she discovered her true calling, allowing her to overcome her educational hurdles in pursuit of a career in biology.
However, her path into the world of marine biology and deep-sea exploration was far from easy, especially in a field historically run by men. At 28, after forging a path in commercial diving—a male-dominated sector—she made the bold decision to chase higher education, turning her past adversities into the fuel for her scientific journey. Sonia knew that to excel and carve out her place in this world, she would need to surpass many who had preceded her. She dedicated herself to becoming a highly trained, certified, and experienced diver, exploring depths that few others dared to venture. This rigorous commitment allowed her to gain insights into our oceans that most never will, positioning her as a true expert in her field.
While some might romanticize scientific life as one of constant exploration and adventure on the seas, Sonia was ready to share the reality involving extensive lab work, administrative tasks, grant applications, and the relentless quest for funding. Yet for Sonia, she’s established herself enough to still get out to sea to conduct her experiments, against all odds.
The Gorgonian Deep Diver
Diving with Sonia offered our expedition team a front-row seat to her deep-sea research on gorgonians. As we prepared to enter the 22°C (73°F) waters, Sonia briefed us on her plan: She was testing a new method for an upcoming Indo-Pacific expedition, using biodegradable dye on an invasive coral species to study their responses to underwater currents, especially at greater depths.
While Sonia was equipped with advanced diving gear designed for long-duration underwater research—called a closed-circuit rebreather (CCR)—our standard scuba gear limited our dive to just an hour at 30 meters. For Sonia, however, 30 meters is only a shallow dive—her true research lies in the Mesophotic coral reefs, also known as the “Twilight Zone,” which extend from 30 to 180 meters. This zone, where sunlight begins to fade, is where Sonia’s expertise shines. Her remarkable dive to 181 meters, a feat that involved nine hours underwater, was made possible by her use of her CCR.
The Gorgonian Lab
Following our intense diving, we transitioned from the unpredictable ocean to the stability of Sonia’s lab, a change of pace to more grounded scientific pursuits. Inside, we encountered an impressive collection of 8,000 gorgonian samples, each awaiting analysis by Sonia and her team. She shared her fascination with the many mysteries surrounding these specimens, particularly highlighting those from Wakatobi, Indonesia, collected from depths exceeding 140 meters. “There’s so much we don’t know about these gorgonians. They are here so that we can try to extract as much information as possible,” Sonia explained. “The deeper we go the less we know.”
Throughout her extensive dives and research in the Indo-Pacific, Sonia has observed a notable phenomenon: the diversity of gorgonian corals at shallower depths generally decreases when traveling eastward, yet remains constant at greater depths. This has sparked questions about coral distribution, their adaptation to changing environments, and potential evolutionary paths, especially in biodiversity hotspots like the Philippines and Indonesia. She distinguishes between corals found within specific depth ranges and those that thrive across various depths, highlighting the role of environmental variables such as light, temperature, dissolved oxygen, salinity, sedimentation, and geomorphology at depths beyond 140 meters.
Geomorphology, the study of the origin and evolution of earth’s surface features, emerges as a critical factor in Sonia’s research, influencing the findings and insights gained from each dive. Basically, she’s focused on the complex interplay between marine life and their habitats, paving the way for a deeper understanding of coral ecosystems and their resilience—especially amidst climate change. Because there’s so little science that’s been done surrounding deep-sea gorgonians, Sonia is on track to break more records, find more species and bring more of what sits so deep beneath the surface to light.
Read the full story on SHE Changes Climate.