Marine biologists discover new plankton off Oregon coast

Nearly every morning when she was a doctoral student in the College of Arts and Sciences (CAS), Nicole Nakata, Ph.D. '23 (biology), would cross the street from the Oregon Institute of Marine Biology (OIMB) in Charleston, Ore., to the high-tide line of the Pacific Ocean. Her job was to catch microscopic brittle star plankton larvae from the incoming tidal current and bring them back to OIMB's labs to analyze under a microscope.

Unnoticed by most people, these "babies of the sea" are everywhere in the ocean.

"These larvae are so beautiful and complex, but they are microscopic," Nakata said. "If you spend time in the ocean, it's probable you've swallowed many larvae."

Nakata now works as a faculty member at the University of Alaska Southeast in Juneau, where she joined as a postdoctoral researcher and instructor in 2024.

After years of working together, Nakata and CAS marine biologist Richard Emlet, previously her doctoral adviser, have published research on newly discovered species of brittle star plankton and documented unstudied larval forms. In their studies, they have also found that Oregon's coastal ecosystems are connected to the broader West Coast region.

Their discoveries were published in the June 2026 issue of Invertebrate Biology.

Documenting plankton species at OIMB

For years, Emlet and Nakata collaborated on this research, spending hours together at the microscope. For Nakata, it was an opportunity to learn from an expert; for Emlet, Nakata brought fresh momentum to complete a project that was years in the making.

During their research, they discovered three new species of brittle star plankton off the Oregon coast and published detailed descriptions of about 10 larval species that had never been photographed or described.

"We'd go bananas whenever we found a new species," Emlet said.

Documenting these microscopic organisms deepens the understanding of marine life along the Oregon coast and reveals how connected local brittle star plankton are to distant regions along the West Coast.

Because immature larvae often look nothing like their adult forms, the researchers had an extra step as they documented their work. They had to match the genetic signatures of larval samples with known adults, a step called DNA barcoding. The genetic detective work led to some surprises. They found larval versions of adult brittle stars whose mature populations were only known to live hundreds of miles away in British Columbia and the San Francisco Bay Area.

These findings also contribute to a crucial baseline for the Pacific Ocean's diverse ecosystems. Discovering that these species spawn during the winter months not only informs local conservation efforts but also expands the understanding of regional marine ecosystems. Studying how ocean animals and invertebrates reproduce allows researchers to see how human activity affects their habitats.

"If we don't know how something makes babies, we can't do anything about it," Nakata said.

Skipping life stages in brittle star plankton

Finding new species and photographing unstudied brittle star larvae broadens the understanding of marine ecosystems. But as the researchers analyzed their samples, they uncovered an even bigger surprise: Some larvae appeared to skip developmental stages entirely.

Many life forms typically progress through distinct phases—the classic example being a hungry caterpillar eating constantly before transforming into a butterfly. But what if a caterpillar skipped the feeding stage and transformed into a butterfly right after hatching?

That's what Nakata and Emlet observed in several brittle stars. They found that the mothers produce eggs large enough to nourish the larvae through early development without the larvae eating, allowing them to progress straight to the juvenile stage.

"This happens often among marine animals, and we found a gold mine of examples," Emlet said. "We had no idea it was happening here in Oregon."

The planktonic stages of Gorgonocephalus eucnemis

Gorgonocephalus eucnemis belongs to a class of animals called brittle stars, or ophiuroids, that date to 500 million years ago. A basket star consists of a hockey puck–like central disk, or body, with five branched arms lined with tiny hooks and spines extending outward.

How El Niño winters affect plankton

While Nakata now works as a postdoctoral researcher at the University of Alaska Southeast in Juneau, Emlet continues his work at OIMB. He plans to examine how plankton larvae behave during El Niño winters, which are seasons marked by warmer-than-average sea surface temperatures in the Pacific Ocean.

Emlet wants to explore how patterns of planktonic larvae change during El Niño events, a question that could yield critical insights into how species' ranges change and marine life responds as climate change warms the oceans. During their long-term study, he and Nakata observed that some larval species occurred only in samples taken during past El Niño events. With an upcoming El Niño winter expected in North America, he looks forward to seeing if that migration pattern continues.

"We wouldn't have noticed that if we had not been at OIMB on the coast 24/7," Emlet said. "We sampled daily. It would've been impossible without sampling so close to the site."