A Simple Guide to Sea Urchins

Growing up, I remember sea urchins being ubiquitous in the aquarium touch pools. I didn't think of these spiny, little sea creatures any other way until I was a young adult and had uni for the first time. Since then, sea urchin and food have been synonymous. In the past, I rarely found sea urchin outside a sushi restaurant, but lately, I’m seeing sea urchin more and more in unexpected places. In 2016, Nestle named it one of the top ten food trends due to their unique flavor. Chefs are finding more creative uses for sea urchin as they push the envelope, and it seems this little “sea hedgehog” is an ingredient that's here to stay.

About the Sea Urchin

Sea urchins are echinoderms most closely related to sea cucumbers and sea stars. Their spherical shells, or tests, are made up of plates and movable spines that protect them from predators. There are about 950 species of sea urchins that inhabit a wide range of depth zones in all climates across the world’s oceans. About 18 of them are edible. They primarily feed on algae and kelp, but are also omnivorous scavengers that will feed on animal matter.

Source: Shape of Life. A time-lapse video shows how urchins actively graze on kelp.

Sea Urchin as Food

When it comes to consumption, sea urchins are harvested for their gonads, also known as uni. These bright yellow to orange lobes are “stockpiles” of sugars, amino acids, and salts: a trifecta of sweet, salty, and umami. It’s been dubbed as the foie gras of the sea given its buttery texture and delicate ocean flavors. Like oysters, sea urchins also vary in flavor depending on its species and diet. Urchin lovers, for example, prize Hokkaido uni because of its flavor, developed from the urchin's diet of Hokkadio macro algae kombu.

The green, red, and purple species have the highest demand globally because their lobes tend to be larger and visually more appetizing. 99% of sea urchin are wild and harvested by diving or drags.

There are about 950 species of sea urchins… About 18 of them are edible.

99% of sea urchin are wild and harvested by diving or drags.

  Source: Food Republic. L to R: Maine, Santa Barbara, and Hokkaido sea urchin.

Source: Food Republic. L to R: Maine, Santa Barbara, and Hokkaido sea urchin.

The Global and Domestic Market for Sea Urchin and Uni

The greatest consumption of sea urchin occurs in Japan, France, and Korea. Japanese consumption, however, wins by a landslide: the country consumes 80-90% of the current global supply. Sea urchin is a traditional staple in Japanese cuisine. Japan was the largest global harvester of sea urchins until the 1980s, but high demand and a decrease in domestic supply forced it to look abroad. From the 1980s to 1994, the US, particularly Maine, was the largest exporter of green sea urchin. Today, it’s Chile, which exports Chilean red urchin and accounts for 50% of global landings. Overall global supply has decreased over the last twenty years due to storms, decreasing kelp beds, invasive species, and over fishing. In 1995, global landings totaled 120,000 tonnes. In 2017, it decreased to 75,000.

In North America, the main sources of sea urchin come from the Canadian Maritime; Maine; and the Pacific coast from British Columbia to California. Green sea urchins are harvested from the Atlantic, while red and purple urchins are harvested from the Pacific. These days, domestic supply stays domestic to meet growing demand and ethnic markets. Domestic supply is also supplemented by imported product, mostly from Chile, during summer months.

How to Prepare Sea Urchin

Sea urchin is usually served raw as sushi, commonly seen in Japanese cuisine, but it has a variety of applications. Mediterranean cuisines have used urchin in sauces, pastas, and on breads for centuries. Modern day chefs are even transforming the ingredient into foams and mousses.

Preparing sea urchin is super easy with super tasty results. Bekah demonstrates how in this quick tutorial.

And as a bonus, here’s a recipe to try from our Pangea test kitchen —
Linguine with Uni and Meyer Lemon