As charismatic as sharks are in popular culture, researchers know very little about their behavior in the wild, especially when sharks are young. Sharks move almost constantly, and researchers have had to rely on chance sightings or very controlled study areas to learn about their feeding and reproductive habits.

So when professor and shark researcher Aaron Wirsing had an opportunity to set up a shark research project in Tetiaroa, he jumped at the chance.

“We know virtually nothing about the early lives of sharks,” Wirsing said. “This is a special opportunity to learn about shark reproduction and the early lives of juvenile reef sharks.”

Ten years ago, Wirsing, a professor in the UW School of Environmental and Forest Sciences, spent about two weeks observing the waters within Tetiaroa’s lagoon and saw many young sicklefin lemon sharks and blacktip reef sharks. It became clear that Tetiaroa’s lagoon was a sanctuary for shark breeding, and that young sharks were spending time feeding and growing within the protected confines of the atoll before venturing into the open ocean.

After a few more years of observations and planning, Wirsing and his collaborators at Florida International University installed an acoustic receiver array that can pick up the signal of individually tagged sharks that swim within range of a receiver. Ever since, the research team has been capturing and equipping sharks with acoustic transmitters that produce signals for up to five years, providing valuable information about where the sharks move. To date, they have tagged nearly 100 sharks and expect that soon they’ll have enough data to know definitively how long newborn reef sharks stick around the atoll before leaving the area.

Because sharks are among the top predators in the ocean, their whereabouts have implications on the entire ecosystem.

“We’re just now hitting peak momentum with the number of sharks that we’re tracking and the kinds of insights we’re getting from these tags,” Wirsing said. “Soon, we’ll be in a really good place to reveal an awful lot about the early lives and ecology of these two reef shark species.”

In the fall, Wirsing and team plan to return to Tetiaroa for another round of tagging juvenile sharks. After a successful trial run last year, the team will equip about 30 young sharks with a smaller tag that can withstand being eaten by a larger predator (often an adult shark). These tags can detect the acidity of stomach acid, at which point they change the kind of signal they are emitting, helping researchers know for sure when one of the babies they tagged has fallen prey to a larger shark.

For bird lovers, Tetiaroa is paradise. The atoll is home to 10 different seabird species, from the Brown Booby, which can weigh more than 3 pounds, to the relatively small White Tern. But little is known about the lives of these birds — their population numbers, how long they live and the factors determining their breeding success.

When UW professors Sarah Converse and Beth Gardner first set up their research project in Tetiaroa, they focused on banding individual birds to understand their survival and movement patterns. They also set up acoustic recorders to track bird activity throughout the atoll’s individual motu (islets). Now, in collaboration with UW School of Aquatic and Fishery Sciences Ph.D. student Amelia DuVall, they’re also focusing on GPS tagging, a technology that lets them track where birds go, how long they are away from the atoll and where they feed. A lightweight tag is attached to a bird’s tail feathers and can remain on the bird for up to a few months. Tiny solar panels recharge the tags, which send GPS location data to a base station on Tetiaroa.

The data can show precisely where individual Brown Boobies travel, and how long they stay in certain locations. The insights they’re getting from the data corroborate traditional ecological knowledge that identifies distributions of seabird species across locations such as nearby Moorea and Tahiti, Gardner explained.

“In talking with the Cultural Director of the Tetiaroa Society, Hinano Murphy, we are learning about the traditional markers of seabird distributions and we are now seeing with GPS technology exactly where Brown Boobies are going when they are away from Tetiaroa and the paths they take to get there. It’s exciting to see some initial results and to better understand the areas that these seabirds have traditionally used, and to potentially identify new important areas, which can provide data to support conservation strategies for the seabirds of Tetiaroa,” Gardner said.

They hope to continue the GPS tagging, perhaps targeting a smaller species of tern, the Sooty Tern, which also forages in the ocean away from the atoll.

Other ongoing work in Tetiaroa is focused on the nesting activity of several seabird species before and after a push to eradicate two non-native species of rat from the atoll. The rats, which likely arrived with colonization several centuries ago, were the only known mammal species on the atoll. The rats preyed on seabird eggs, and likely impacted the entire Tetiaroa food web. After several years of monitoring, the researchers, along with UW School of Environmental and Forest Sciences master’s student Eve Hallock, are now starting to analyze the data, looking for patterns in seabird activity and nesting before and after the rats were present.

“Tetiaroa offers an amazing opportunity to study seabirds on a remote atoll. This work would be nearly impossible without the support of the Tetiaroa Society, a non-profit dedicated to facilitating research and conservation on Tetiaroa, and the generous UW donors who support this work. After five years, we are starting to gain some real insights into factors that determine the well-being of seabird populations on atolls. These results are pointing to additional possibilities to restore ecological integrity on tropical atolls around the world,” Converse said.

UW professors and chemical oceanographers Alex Gagnon and Julian Sachs are testing the effects of increased levels of carbon dioxide on sea life in the ocean. As carbon dioxide levels continue to rise, the world’s oceans absorb some of this carbon, making the water more acidic. Ocean acidification has already upset ecosystems such as coral reefs and nearshore organisms such as shellfish.

Their study in Tetiaroa simulates carbon dioxide levels that are predicted for the year 2100. The team leveraged the eco-resort’s air conditioning system — which pumps to the surface cold, carbon dioxide-rich water from 900 meters (2,900 feet) deep — to simulate potential changes in seawater pH over a small patch of coral reef near Tetiaroa.

In future months they will automate this experiment so it can run over a long period, with close monitoring of the chemical, physical and biological changes that occur on the reef. This will help understand the impact climate change continues to have on coral reefs, especially if carbon dioxide levels keep rising this century.

“Coral reefs are wondrous ecosystems with a mind-boggling diversity of fish, invertebrates, algae and microbes,” Sachs said. “Like a fine-tuned orchestra, each member of the intertwined system plays an important role in the functioning of the whole. Acidifying and warming oceans are disrupting these relationships in often unpredictable ways. We’d like to simulate the conditions expected later this century to better understand how they will respond.”

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The key to this research was figuring out how to extract carbon dioxide from ocean seawater and move it to another location. Gagnon and Sachs realized they essentially had created a new carbon removal technique that was massively cheaper and more energy efficient than other carbon removal methods. So in 2022 the scientists licensed their technology and created UW-spinoff Banyu Carbon.

About 8 million tons of plastic enter the ocean each year, and that rate is expected to increase tenfold by 2025. More than 90% of the plastic found in oceans are microplastics (fibers smaller than 5 millimeters, or about the size of a pencil-top eraser). Jacqueline Padilla-Gamiño, a UW associate professor of aquatic and fishery sciences, is trying to establish a baseline of the microplastics around Tetiaroa. This is important for understanding their potential impacts on organisms and planning for the future.

“Our first priority is to understand how many microplastics are there and whether there are hotspots for microplastics or areas where plastics are more likely to get stuck,” Padilla-Gamiño said. “Unfortunately, plastic is just increasing. That’s the reality. It’s important to know where we are now, and to get a better sense of impacts for the future.”

Padilla-Gamiño has worked extensively in French Polynesia, including on the neighboring island of Moorea, but the atoll of Tetiaroa is new grounds for her. Her lab made its first trip in 2022 to establish a long-term research project on microplastics and their impacts on sediment and coral organisms near Tetiaroa. They collected water and sand samples from the different motus, or small islands, within Tetiaroa for analysis. Soon, they will have a good picture of how sediment and microplastics are distributed throughout the atoll.

Padilla-Gamiño plans to return to Tetiaroa in the fall to focus more on the sediments distributed across the atoll, which will help them better understand which species live in the area. She also focuses on coral organisms — which species live there and when they reproduce.

A vision for scientific research and conservation

When Marlon Brando was filming “Mutiny on the Bounty” he fell in love with French Polynesia and later purchased Tetiaroa in 1966. Years after his death, The Brando Resort was built and, following his wishes, scientific research and conservation efforts were embedded in the vision. In partnership with the Tetiaroa Society, researchers are invited to work at the scientific eco-station on the atoll, a facility that has become a hub of research and conservation work for both local and international experts.

The Seeley family — who are proud second-generation alums of the University of Washington — brought together Tetiaroa Society, the family of The Brando Resort owner Richard Bailey, and a growing community of donors to provide funding for long-term UW research projects over the past decade. The Seeleys hope their support will inspire other donors to also support this impactful research.

Mark Stone/University of Washington

“As a family, we are proud to partner with the UW in this way, and we hope to inspire even more people to join us in building a legacy of positive environmental impact by supporting UW’s scientific research on Tetiaroa,” said David J. Seeley, who served as Marlon Brando’s general counsel and continues to represent the Brando family’s interest today.

Private support has not only advanced our knowledge of important and delicate ecosystems, like that of Tetiaroa’s, but it has also informed research discoveries to help protect marine environments across the globe amidst a rapidly changing climate.

Story by Michelle Ma. Photography by Mark Stone and Tetiaroa research partners.