Hakai Magazine

Coastal science and societies

A bowl of uni ikura don
Sea urchin gonads are used in a variety of dishes, from sushi to soup to pasta. Photo by SOURCENEXT/Alamy Stock Photo

Avant-Garde Gonads

An overlooked sea urchin species may find a spot on the menu as the climate shifts.

Authored by

by Kristen Pope

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Off the coast of Southern California, climate change is disrupting the ocean and the sea life within. As the ocean warms, oxygen levels decrease, and acidity rises, scientists are studying how these changes are affecting species—including the ones people eat. Some scientists are even trying to gauge which species will be the seafood of the future.

Sea urchin gonads, called uni, appear in sushi and other dishes, but many urchin species are very susceptible to climate change—including the ones fished most regularly off California. In a recent experiment, scientists led by Okinawa Institute of Science and Technology marine biologist Kirk Sato* explored the possibility of opening up a commercial fishery for fragile pink sea urchin in California. Despite the “fragile” in its name, this species is actually quite hardy, and the scientists think it can be a viable uni alternative should the most commonly used red, green, and purple species succumb to climate change.

“Pink urchins live in a deep-sea environment where the oxygen and pH levels are already much lower than in shallower waters where currently fished urchins live,” Sato says by email. “As the oceans are predicted to become more acidified and deoxygenated due to climate change, we think that these pink urchins may be better adapted to deal with the changing environment.”

Pink urchins can be found 250 to 300 meters below the sea surface. Prawn fishers work these areas and often pull up pink urchins as by-catch, but are forced to toss them back since there isn’t a commercial market for them. However, the species is quite palatable. “Pink urchin uni has a mild smell and flavor,” says Sato. “It tastes creamy with a slight sweetness.”

Yet pink sea urchin uni is 80 percent smaller than that from red sea urchins, making it less appealing for sushi. “It’s on the small side for the traditional uni topping,” says study coauthor Lisa Levin, an oceanographer at the University of California San Diego. Levin notes the smaller uni may be well suited for flavoring dishes such as soup.

Whether or not a commercial fishery opens for pink sea urchins, scientists will continue to look for alternative foods to meet the needs of a changing world. “Thinking about new fisheries or new ways to use species that are caught incidentally is going to be part of our adaptation to climate change,” Levin says.

*Correction: Kirk Sato is a postdoctoral researcher at the Okinawa Institute of Science and Technology, not a doctoral candidate.