British Columbia

From 'zombie' urchins to seafood gold? Studies test sea urchin farming in Canada

Federal scientists and others are exploring the possibility of sea urchin farming in Canada, using Norwegian technology that proponents hope will turn 'zombie' urchins which can denude kelp beds into profitable seafood — but there is a question about the ecological cost.

Pilot studies to test how Norwegian feed works to boost lucrative 'uni' in Canadian urchins

A farmed sea urchin with prized yellow-orange gonads, known as 'uni' to sushi lovers, after 12 weeks on a diet of manufactured feed including kelp and fish meal. (Urchinomics)

Federal scientists and others are exploring the possibility of sea urchin farming in Canada, with at least six pilot studies using Norwegian technology that proponents hope will turn "zombie" urchins which can denude kelp beds into profitable seafood.

The first of the studies, conducted by Fisheries and Oceans Canada, is expected to start next week in waters off Vancouver Island, with others planned for Newfoundland, Quebec and Nova Scotia.

Wild urchins are harvested in B.C. and elsewhere, but aren't farmed commercially anywhere in Canada — yet.

"It's a new species for aquaculture, which is interesting for me," said DFO research scientist Chris Pearce, who is leading the federal trial at Pacific Biological Station in Nanaimo, B.C.

The DFO study will use about 2,000 green and 1,000 red urchins harvested by divers from the Strait of Georgia and fed in trays suspended in the ocean near the station.

It will test how the Norwegian feed works on local wild-caught urchins to produce the bright orange blobs — technically, gonads — that delight adventurous sushi lovers as "uni" and fetch something like $150 per kilogram at market.

"We can take near-valueless sea urchins ... and turn them into super seafood products within two to three months," said Brian Tsuyoshi Takeda, founder of Urchinomics, the Norwegian company behind the aquaculture system.

But the efforts to birth a new aquaculture industry are already running into questions about the ecological cost.

Urchinomics' technology, including feed and suspended trays to hold the urchins, has already been tested at sea near Miyagi, Japan, said Brian Takeda, founder of Urchinomics. (Urchinomics)

'Zombies' in the barrens

The difficulty in harvesting wild urchins is they may or may not contain the uni (also called roe) that is so in-demand.

Urchins living in big, healthy kelp beds tend to have high-quality roe, said Pearce.

But the most abundant populations, where the sea floor is literally covered with spiny urchins that have clear-cut the kelp around them, are the least likely to have commercial-grade uni.

Urchins from areas devoid of kelp, known as 'urchin barrens' because the grazers have clear-cut all the algae around, don't have the energy to make roe. (Urchinomics)

"If you get an area that has a large population of sea urchins, they can graze down the algal beds ... and you end up with nothing but urchin barren grounds," said Pearce.

"They've basically eaten themselves out of house and home."

Those so-called "urchin barrens" can cause ecological trouble as well, because the munching urchins stop growth of the kelp forests that provide important habitat for fish and other species.

With the demise of sunflower stars in B.C.'s Howe Sound in 2013, green sea urchins proliferated, turning areas that were previously lush with kelp forests into 'urchin barrens.' (Donna Gibbs/Vancouver Aquarium)

"After they eat the kelp and destroy everything, they don't die," said Takeda. "Suddenly, you have this massive biomass of empty, zombie-like urchins,"

Takeda says using Urchinomics' feed, an aquaculture operation could remove these urchins with low commercial value — that some see as destructive — and fatten up their gonads for market.

Takeda believes that business opportunity could have a knock-on benefit for kelp ecosystems.

"If we do what we do right … that patch of ocean floor that was occupied by empty zombie urchins, that will return to kelp state."

Kelp forests provide habitat for a whole ecosystem of animals in the ocean, so the loss of kelp can have cascading implications for other creatures. (Monteray Bay Aquarium)

Feed includes fish

However, the feed that Urchinomics makes, which is manufactured in Norway and approved by the Canadian Food Inspection Agency for the experiments, raises a sustainability concern, says a marine ecologist.

The feed is mostly kelp, without any hormones or antibiotics, but it also contains fish meal, according to Urchinomics.

"What worries me is using animal protein," said Anne Salomon, an associate professor at Simon Fraser University, who studies kelp forest ecology.

Urchins are primarily herbivores, and Salomon is concerned about them eating much higher on the food chain, using fish from another part of the world.

"It becomes energetically very costly to the environment," said Salomon.

The urchin feed for the Canadian trials is coming from Norway and contains kelp, with less than 10 per cent fish meal, according to the company behind it. (Urchinomics)

Salomon thinks aquaculture can be sustainable and necessary to feed the world's population, but hopes DFO and any commercial players will fully examine the costs to the system.

"If this is sold as a green solution, I would say let's look into how green or orange or red it really is."

Takeda said the fish meal is less than 10 per cent of the feed, and comes from off-cuts like the spine, head and tail of fish processed in Norway for human consumption.

There are other questions too, familiar to anyone who has followed debates about salmon aquaculture, such as waste on the ocean bottom, from urchins above eating and defecating.

Takeda said that will be studied by independent scientists as the Canadian research progresses.

"The concept of urchin farming is all about ecological restoration," he said.

"We want to take the destructive urchins … and get them out in an economically sustainable way."

Orange roe is seen inside a sea urchin in a processing facility in Portland, Maine, in 2011. (The Canadian Press)


Lisa Johnson is an editor and senior writer at CBC News, and a producer of CBC Radio's What On Earth. She enjoys making sense of complicated things and has also reported for CBC TV and radio in B.C. with a specialty in science, nature, and the environment. Get in touch at or through Twitter at @lisasj.