DELICIOUS
SEA URCHINSRESTORE OCEANS AND HELP DECARBONIZATION
The disappearance of kelp forests in the oceans causes great damage to marine ecosystems and is becoming anincreasingly serious threat around the world. One Japanese startup company tackling that problem is drawing
international attention not only because of its efforts to restore oceans into vibrant ecosystems, but also for its
value-creating business model.
Sometimes called “nurseries of the sea,” kelp forests
sustain a whole host of aquatic life. These rich seaweed
forests have in recent years attracted attention as blue
carbon ecosystems for their ability to capture andsequester carbon dioxide from seawater. However,barren seafloors, devoid of such fertile feeding andbreeding grounds, have become a grave threat for
oceans worldwide. One cause of that problem is
sea urchins, uni, which, because of rising seawatertemperatures from global warming and other factors,
have been able to reproduce unhindered, leading
to overgrazing on the kelp forests. Sea urchins are“When you look at sea urchins every day,you can tell whether they are feeling goodor bad. I think that sea urchins are morestraightforward than people,” says ARAI
Miho, whose knowledge gained throughmany years of work on wastewater
treatment is now devoted to sea urchins.

in increasing demand worldwide as a high-end
ingredient in Japanese cuisine such as sushi, but thosesea urchins that have overgrazed kelp forests down
to the barren seafloor essentially starve and become
empty. Since there is nothing to eat inside them, they
have no commercial value and were previously simply
discarded.
While many people involved in the fishingindustry have been left scratching their heads, thecircular business model of the Japan-based startup
Urchinomics is a ray of hope to solve that problem.
Urchinomics engages with fishers to procure empty

Top: “Zombie” urchin—empty sea urchins are almost devoid of anything
edible.
Bottom: Sea urchins farmed at the Kayoi Uni Base just before being
shipped. These sea urchins are filled with plump roe and shipped aspremium seafood.

sea urchins, cultivate them through ranching on ashort-term basis, and ship them to restaurants andsushi chains throughout the year as valuable marine
products.
A catalyst for that model was the Great East Japan
Earthquake of 2011. Along the Tohoku coastline,
sea urchins appeared prolifically due to changes in
the marine environment caused by the tsunami. The
proliferation of sea urchins led to wider desolationon the seabed. Aware of the current plight, a project
began with the help of Norwegian technology, which
had been used to conduct advanced research in sea
urchin farming. Urchinomics was established in2017, leading to the world’s first sea urchin farm being
set up in Oita Prefecture in 2021. Initiatives such as
that—namely, those that treat environmental issues
as a business and which can help create jobs for thelocal community—are increasingly in the spotlight.
Urchinomics’ second facility in Japan, Kayoi Uni
Base, was created in 2022 in Yamaguchi Prefecture.
Built in collaboration with a local seafood processing
company, the huge farm has an annual production
capacity of 34 tons, making it the largest sea urchinranch in the world. At the heart of the sea urchin farmis a unique compound feed made primarily from theoffcuts of kombu kelp (harvested sustainably), andan efficient ranching system designed specifically forbreeding sea urchins on land. Coupled with that isexpertise in knowing how to reliably ship sea urchins
without exposing them to the natural environment
during their breeding period of two to three months.
ARAI Miho, a water treatment specialist and plantengineer, says, “There are still many things we don’tknow about sea urchins. Focusing solely on levelsof water quality will not produce high-quality sea
urchins full of roe. It’s a daily process of trial anderror. Yet, the quality of the sea urchins we can shipfrom our farms is the key to our circular business, so I
feel a great sense of satisfaction.”
Urchinomics was endorsed for its exemplaryinnovation in the United Nations Decade of Ocean
Science for Sustainable Development in 2022. And
through its kelp restoration efforts from 2021 to
2022 to remove empty sea urchins, Urchinomics
secured blue carbon credits equivalent to 2.6 tonsof sequestered carbon. That had only previously
been done with mangroves overseas, but now Japan,
blessed by waters on all sides, is the first country in
the world to obtain blue carbon credits from kelpforests.
Today, demonstration experiments are underway
not only in Japan but also in the United States,
Canada, New Zealand and other countries where
there is much interest from fisheries. The goal ofUrchinomics is to roll out the sea urchin ranchingbusiness to all regions that suffer from overgrazed,
desolate seafloors, helping to restore the rich andvibrant nurseries of the sea. With passion andtechnology, the challenge for Urchinomics rolls on.There are about 200
tanks in the ranchingfacility where water
suitable for sea urchins is
processed through aclosed circulation systemcalled the Recirculating
Aquaculture System.