University of Hawaii scientist grows tropical sea urchin in lab

As a child growing up in France, Charley Westbrook remembers watching famed marine biologist Jacques Cousteau on television and dreaming of studying marine life and scuba diving around the world.

At age 10, he saw a National Geographic special that featured the University of Hawaii’s famed Coconut Island marine biology lab.

“I remember thinking someday I’m going to go there and study marine biology,” he said. “I’m fortunate to be able to live out that dream.”

Westbrook, now a Hawaii Institute of Marine Biology doctoral student working in the Smithsonian’s National Zoo and Conservation Biology Institute laboratories on Coconut Island, has become the first person to successfully grow a tropical sea urchin from cryopreserved embryos in the laboratory.

The breakthrough could impact coral conservation and offers opportunity for the aquaculture industry. It follows seven years of trial and error, triumph and heartbreak, not to mention plenty of hard work and perseverance.

There were many times when Westbrook felt like quitting.

“At times, did I think it would be wiser to walk away?” he said. “Yes, but if someone else had figured this out, it would have made me sick, and I would have felt awful.”

More than 950 species of sea urchins play a key role in reef ecosystems. As grazers, they naturally reduce algae cover and maintain the balance needed for coral to live in tropical waters.

The species that Westbrook focused on was Tripneustes gratilla, also known as the collector urchin, a native species found at depths of 7 to 100 feet in Hawaiian waters and other tropical regions.

While embryos from cooler, more temperate urchins have been cryopreserved (kept alive in frigid temperatures) and settled, T. gratilla is the first tropical urchin to have settled and metamorphosed after cryopreservation, according to the Smithsonian.

It was not easy and there were many obstacles. But working with the Smithsonian cryopreservation and aquaculture team, led by marine biologist Mary Hagedorn, Westbrook was able to first cryopreserve the embryos and then rear the thawed lifeforms on a diet of phytoplankton as they developed through various planktonic forms during the pelagic larval phase of their lives.

When one of the tiny, swimming creatures finally “settled” on the glass of a laboratory beaker as a baby urchin, Westbrook was overwhelmed.

“I was the only one in the lab, and I was screaming,” he recalled. “I was texting pictures to everyone, and when someone said they didn’t know what it was, I said, ‘You don’t understand — this is years of work!’”

Smithsonian officials described the achievement as the first step in a proof-of-concept process for warm water coral restoration efforts and a new food production opportunity for the aquaculture industry.

Westbrook’s work may someday even benefit the state’s sea urchin hatchery, which takes parent collector urchins from local reefs and allows them to spawn before planting the offspring on reefs under attack by invasive algae.

The Oahu hatchery has produced hundreds of thousands of urchins over more than a decade and has helped to restore hundreds of acres of Kaneohe Bay reefs covered in algae.

Westbrook said his technique may eventually allow the hatchery to increase production during regular intervals when the urchins are not spawning.

Westbrook, 33, came to Hawaii as an 18-year-old and enrolled as a sophomore at UH-Manoa. He earned his bachelor’s in marine biology (and French), followed by a master’s in marine biology before he was accepted into the university’s doctoral program.

He became interested in the collector urchin after volunteering with the Nature Conservancy and helping to run the Super Sucker, a barge outfitted with a suction pump that removed thick mounds of the algae from Kaneohe Bay coral reefs. The Super Sucker isn’t needed anymore because sea urchins are now addressing the algae.

Urchins and coral reefs have declined worldwide due to habitat destruction, overfishing, climate change, sedimentation, natural disasters and oil spills. Climate change has resulted in bleaching events that stress corals and can lead to disease or death.

Maintaining a diverse coral reef grazing community that includes sea urchins is vital to the ecosystem’s overall resilience and capacity to endure future stress events, Westbrook said.