Transforming the 'Roombas of the ocean' into culinary delights

Updated March 27, 2022 at 8:18 AM ET

It's very hard to kill a purple sea urchin. Starve it for years, and it will fall dormant on the ocean floor, devoid of any flesh — just an empty, spiky shell awaiting its next meal. They're like the "Roombas of the ocean," says biologist Doug Bush. And the voracious creatures are decimating kelp forests along the California coast.

In recent years, warming waters and disease have threatened sea stars, the urchins' main predator, allowing the Pacific purple sea urchin population to explode. Scientists say the overpopulation of purple urchins have had devastating effects on the coastal ecosystem and helped drive a 95% loss of kelp forests in the region — what marine biologists often refer to as the "lungs of the ocean."

So, if we can't beat them ... why not eat them? Bush is asking consumers that very question — by transforming the hollow purple urchins into delicious, marketable uni.

The biologist works with purple urchin divers, who bring the creatures to the Cultured Abalone Farm in Goleta, Calif. He places the empty urchins into a seaweed-filled tank for 10-12 weeks, during which the urchins feast and fill with rich, buttery flesh.

"They just plump right up," Bush told NPR's Scott Simon in an interview on Weekend Edition. "You crack them open, and they have such a unique flavor that doesn't exist anywhere else." Bush has sold his purple uni — the edible part of the spiny creature that produces roe — to dining establishments throughout the state, like the Michelin-starred restaurant n/naka as well as casual eateries like Broad Street Oyster Company.

The red sea urchin, the purple urchin's smaller cousin, still dominates the California seafood scene. Chefs and biologists on the West Coast have been working to raise awareness of how putting purple uni on peoples' plates might contribute to a healthier coastline.

Try this chef's tangy purple urchin recipe

Jacob Harth, an New York City-based chef who is opening a seafood restaurant in Brooklyn, prefers his purple uni straight from the ocean — its juice sucked right out of the shell. "It's electric. The citrus, salt brine — it's delicious."

Inside the shell, he finds tiny beads of kelp that, to Harth, taste like caviar. As for the roe, he loves placing it on top of toast, topped with a drizzle of olive oil.

For those who aren't lucky enough to feast on the beach, Harth recommends a fresh-tasting, tangy ceviche recipe:

After cleaning the urchin and leaving the roe in the shell, Harth pours fermented tomato juice and gooseberry juice directly into the shell. (Lime and lemon juice also work perfectly.) Then, he lets the roe bathe in the juices for 4 hours.

"You can eat it straight out of the shell in a soup," Harth says.

Copyright 2022 NPR. To see more, visit https://www.npr.org.

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