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Sea Urchins: A Palatal Gift From The Ocean That One Should Not Miss

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Deepa is a freelance researcher and journalist. She writes and makes documentaries and videos.


Uni Facts

Culinary experts describe the taste of sea urchins as sweet and salty in an oceanic way. Ocean floors with rocky bottoms are the breeding ground for sea urchins. Sea urchin is an echinoderm, a family of marine invertebrates and includes sea cucumber, starfish, sand dollar and crinoids. Their bodies have a common feature, radial symmetry. Once harvested, the sea urchin is split open and the golden yellow gonads inside, arranged like the petals on a flower, are extracted. There will be five gonads inside a sea urchin. Mostly, they are eaten raw, especially with Sushi in Japan. The sea urchins are playfully called the hedgehogs of the sea. Their thorny outer shell justifies the name. Do you know that during larval growth, the sea urchins turn themselves inside out and then the thorny inside (all developed, by then) becomes its outer shell?

Sea Urchins: Among The Few Food Items Harvested From The Wild And Eaten Raw

Sea urchins live for decades and even centuries if left to themselves. Without any haste, they move upon the rocky bottom of the sea, eat whatever they come across, and grow. They are seen on the seas all around the world. They have to be handpicked by harvesters as they are very delicate to handle. In Korea, women scuba divers are the experts harvesting uni.

Not everyone could love the taste of uni. It smells of the sea, has a briny taste and a slight sweetness accompanies its creamy texture. Uni lovers testify that it is an acquired taste.

Sea urchins feed on sea algae. For us, they are a good source of omega-3 fatty acids. There are also plenty of proteins and antioxidants in the uni. The fat content is mostly unsaturated fat.

Uni Sushi is the most common food prepared using uni. It is cooked rice wrapped in a sheet of seaweed and topped with raw sea urchin gonads. They also form part of salads and sometimes are served in their outer shells.

Cultivation Method of Sea Urchins in Coastal Sea


Sea Urchin Farming

Uni is abundantly found on the Californian coastal seas. There are male and female sea urchins. They release sperms and eggs into the seawater that surrounds them and eggs are fertilised soon. The embryo swims in the sea for a while, develops into the curious shape of a space lander and once the familiar thorny adult completes the growth inside it, it turns itself inside out. Just before this burst of maturation, the embryo attaches itself to a rock. What emerges is a well-shaped sea urchin with thorns and many tubular feet.

Some sea urchin species are not palatable. They come in many colours- green, pink, purple, red, black, and pale yellow. This sea species is among the most sensitive creatures of the world when it comes to responding to global warming and climate change.

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Japan has been successful in breeding sea urchins on commercial farms. Eggs and spawns are collected from sea urchins and fertilised in a laboratory setting. Once the embryos hatch, they are grown in artificial tanks until they become mature enough to survive on their own. During this entire period, they are fed sea algae. They are voracious feeders. Sometimes they are kept inside the farm for one year or more and then harvested or they are released into natural water enclosures from where they can be harvested later.

Sea Urchins Sometimes Cover Themselves With Rocks and Other Materials


California Has A Sea Urchin Problem: Just Eat Them To Solve It

Sea urchins exhibit self-covering behaviour under environmental stress. They tend to cover themselves with pieces of rocks and shells. Scientific studies suggest that this covering helps them protect themselves from predators, physical damage, from intense sunlight, and also these covering materials can function as a source of food.

Just like how cattle grazing depletes our terrestrial environment, sea urchin grazing impoverishes the marine environment. The sea urchins destroy the green algae ecosystems by feeding on them. California is facing a serious problem of sea urchins destroying its environmentally valued kelp forests in its coastal marine ecosystem. Since 2014, the increase in the population of sea urchins in the Californian coastal sea has been 10000%, according to a Guardian article. The destruction of the kelp forest destroys the entire marine life including the fish that sustains feeding on it. The underwater terrains where more than 95% of the kelp forest is destroyed are called urchin barrens as there would be nothing there than the expansive carpet of sea urchins trodding the ground. Scientists have been asking Californians to make sea urchins a daily part of their diet so that the population can be controlled.

Now, a quick tip on how to keep sea urchins once bought or harvested. They can be kept fresh in saltwater for many days. They can also be covered in a damp cloth and kept in the fridge.


The Solution to California’s Rampant Sea Urchin Problem is to Eat Them, I Gave it a Try, Vivian Ho,

Sea Urchins Pull Themselves Inside Out To Be Reborn, Deep Look, Youtube.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Deepa

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