Kelp! They Need Somebody … To Eat Sea Urchins

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Denise MacDonald holds a purple sea urchin at the Bodega Bay Marine Laboratory. (Ryan Tamborski for KQED. Use with permission)

Denise MacDonald held out a tray of spiny purple sea urchins. The roe, served in the shell and the color of egg yolk, contrasted nicely with the urchin's dark, purple spines. MacDonald, director of global brand marketing at a company called Urchinomics, invited me to have a taste. I scooped up a blueberry-sized amount with a spoon.

It's good: salty, fresh, creamy.

"Tastes like the sea," I said.

"But with a buttery aftertaste," said MacDonald.

Urchinomics and its partner, the UC Davis Bodega Marine Laboratory, are running a trial designed to develop methods for ranching purple sea urchins for profit, while at the same time addressing the consequences of a nasty ecological chain reaction.


In 2014-15, sea stars began dying en masse from a mysterious wasting disease, which scientists believe was exacerbated by a massive blob of warm water that spread throughout the Pacific Ocean.

Because starfish prey on sea urchins, the latter population's exploded when the former's dwindled. The urchin boom had a profound effect on another ocean-living organism: kelp, a type of seaweed.

"During that time, the urchin populations ... started to eat all of the kelp forests along our coast," said Laura Rogers-Bennett, an environmental scientist at the Bodega Marine Laboratory.

The ocean hasn't been the same since.

"More than 90% of the kelp forest has disappeared from San Francisco up into southern Oregon and has been replaced by sea urchin barrens," Rogers-Bennett said.

Normally, a kelp forest provides a wealth of benefits, harboring fish, sequestering carbon, preventing shoreline erosion and producing oxygen. Areas bare of kelp can't do any of that.

But while the regrowth of trees takes decades, these kelp forests could bounce back.

"They're very fast-growing," said Rogers-Bennett. "It would take them only six months to rebound, if we could remove some of this urchin-grazing pressure."

And that's where eating purple sea urchins comes in ...

The contrast between an urchin just brought in from the barrens (left) and an urchin plumped up on kombu seaweed in a lab trial, demonstrates the effectiveness of the urchin ranching operation at the UC Davis Bodega Marine Laboratory. (Ryan Tamborski/KQED)

Introducing Your New Favorite Delicacy 

"What we're doing here is we're looking at a financial incentive model that makes these purple urchins of value," said Karl Menard, aquatic resources manager at the Bodega lab.

The idea is that divers can collect urchins off the coast by the thousands and relocate them into a sort of urchin ranch. The urchins, having gobbled up an entire seaweed forest into nonexistence, frequently arrive at the lab in a state of starvation. They are raised in plastic crates and fed pellets of dried algae, made from the trimmings of kombu, a type of kelp that is processed in factories for human consumption. That diet can fatten them up in about eight weeks.

Karl Menard lifts a tray out of urchins out of the water in the Bodega Marine Lab urchin ranching operations. (Ryan Tamborski/KQED)

The "roe" or uni is already a delicacy in Japan and commonly used in sushi. (Technically speaking, roe is a mass of eggs, but uni are urchin gonads.) A live urchin full of uni can be sold for good money.

"They would be considered a premium product and could be worth $8 or $10 or more in the market," said Menard.

The hope ultimately is to make urchins a common food anywhere they have created a barrens on the Pacific coast.

MacDonald envisions one day being able to go into seafood restaurants to try urchin from different regions, the way we do now with oysters. "I think that there's there's room for that," she said.

This month Urchinomics opened a commercial site in Oita, on the Japanese island of Kyushu. The company is currently negotiating a lease for a property in Bodega Bay, and it's hoping to be fully operational in 2020.