Including uni in your next sushi order could reportedly help the fight against climate change.
Kelp, a type of seaweed that sequesters carbon, is a source of food for many organisms and provides shelter for many forms of sea life.
Critical to marine ecosystems, kelp is now in danger of running out in California due to the growing number of purple urchins that feed on them.
Now, sea urchin farmers are reportedly contributing to the fight against climate change by removing hungry urchins from kelp fields in California, reports Fast Company.
While fulfilling urchin supply to the sushi market, urchin farmers are also saving the kelp so it can play its part in helping the climate.
“Urchin ranching is part of a larger strategy to reset the ecosystem and prepare kelp to recover,” says Norah Eddy, the associate director of the oceans program at the environmental organization Nature Conservancy.
Nature Conservancy has been monitoring the remaining kelp to identify the best places to intervene and are considering partnering with a startup to address the problem.
According to the organization, California’s North Coast has lost around 90% of the kelp over the last decade. Sensitive to warming water, kelp suffered heavily in 2013 when a marine heatwave began in the Pacific. The population of purple sea urchins exploded when stars, a predator of sea urchins, were killed off by disease.
Sea urchins are known to be vicious kelp consumers and even after devouring an entire kelp forest would wait for them to grow back just to gobble them up again. This urchin activity usually leaves an area known as “urchin barren,” a desert-like area where seaweed is no longer able to grow.
Removing sea urchins will help the restoration of kelp as shown in a recent trial done by the nonprofit Bay Foundation. Based on the findings, kelp began to regrow within weeks and the tiny new seaweed quickly became a full-grown forest off the coast near Los Angeles.
As it turned out, kelp has the ability to grow as much as two feet a day, absorbing up carbon through photosynthesis as it grows. When dead kelp drifts down to the bottom of the ocean, carbon is then stored permanently. According to estimates, macro-algae such as kelp sequester 634 million metric tons of carbon dioxide each year.
To ranch the sea urchins, Nature Conservancy is set to work with startup Urchinomics, which first realized the impact of the species in Japan following the 2011 tsunami. Japanese fishermen discovered that there was nothing left to fish after urchins grew in number.
“The tsunami washed away the predatory species for urchins, which allowed the urchins to explode 700%,” Urchinomics CEO Brian Tsuyoshi Takeda explained. “When the urchin population exploded, it totally decimated one of the world’s most productive coastal ecosystems.”
Farming sea urchins was not an option before as fish feed typically melts into the water faster than urchins can eat them. However, the new type of feed developed by the Norwegian government made it possible to grow urchins in aquaculture. This makes it possible for the startup to harvest sea urchins from the water and then raise them to produce uni (the Japanese word for a sea urchin’s gonads), the edible part of urchins.
Urchinomics has secured the rights to the technology and improved on the ingredients to make them sustainable.
“We developed, essentially, a new version of the feed that is super sustainable and can turn a pest urchin from an ecological problem to one of the world’s most premium seafoods on the planet in eight to 12 weeks,” he explained.
According to Takeda, sea urchins are responsible for the destruction of many kelp forests in other parts of the world.
“What typically happens is that when you overfish predatory species—lobsters, crab, cod, herring, all the fish that typically taste good—and you don’t really take into consideration what happens to the rest of the ecosystem when those predators disappear and urchins explode in population,” noted Takeda.
Urchinomics is set to build its first commercial aquaculture systems for markets in Japan, Canada, Norway and California. Takeda shared that they are working on multiple properties in California as the state “is in a very critical situation.”
Nature Conservancy and nonprofit organizations will be harvesting the sea urchins from the kelp beds in California and send them to the startup. The startup will sell the food and then send part of the proceeds back to the nonprofits to help sustain the project.