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, 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.

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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.

'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.

"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.

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"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."

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.

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."