TORONTO - The arrival of plant-based meats at chains including A&W and Tim Hortons is just the first step towards mainstream sustainable eating for Blair Bullus.

The Vancouver flexitarian and businessman has his eye on the next frontier: Fish and seafood alternatives that - like products made by Beyond Meat and Impossible Foods - mimic the look and taste of the real thing for pescatarians not quite ready to give up sashimi.

It's still a nascent movement, but Bullus points to faux experiments that have popped up in recent years, ranging from chickpea-based “tuna” to carefully carved smoked carrot “salmon.”

Bullus' company Top Tier Foods Inc. actually sells quinoa, including an especially sticky variety designed to replace rice in vegan sushi rolls that otherwise don't have the protein and omega-3 fatty acids of fish.

It's available at the Quebec City-based chain Yuzu Sushi where customers can pair it with faux ahi tuna - a coral-red facsimile carved out of Roma tomatoes. Known as Ahimi, it's made by New York's Ocean Hugger Foods.

Bullus doesn't expect to fool sushi eaters with the combination, but he hopes it can at least assuage any nutritional and environmental concerns by those who ditch fish.

“It's just becoming easier to make those decisions so you don't necessarily have to give up sushi or you don't have to necessarily give up your salmon and avocado roll,” Bullus says.

“You're going to have an alternative that has the same mouth-feel as what you're used to.”

Whether the average omnivore is ready to give up their salmon and shrimp has yet to really be tested.

Efforts to produce realistic sushi-grade varieties are dwarfed by the research, funding and marketing push behind plant-based and lab-grown beef, says Bruce Friedrich, co-founder and executive director of the Good Food Institute.

Nevertheless, he says seafood alternatives are just as necessary, describing the environmental impact of commercial fishing as “at least as bad as cattle-ranching” and akin to “the strip-mining of our oceans.” He also lambastes aquaculture for its use of antibiotics.

“If these were terrestrial farming practices, people would be horrified,” says Friedrich, whose Washington, D.C.-based institute has funded open-sourced research into plant-based projects at the University of Manitoba and University of Guelph, as well as research on lab-grown meat - also known as cell-based meat - at the University of Toronto.

“Obviously, you know the link between seafood and human slavery, the pathetically lax regulation of the seafood industry to the degree that you don't even know what you're getting, the amount of mercury and dioxin and lead and other forms of contamination. This is an industry that is ripe for transformation.”

Yuzu spokeswoman Julie Lamothe says the chain's 68 stores in Quebec and three in New Brunswick added Ahimi in April after customers asked for more veggie varieties.

Photos on Yuzu's website depict maki-style rolls punctuated by the bright hue of Ahimi, while a nigiri-style sushi shows that when excess moisture is removed, the tomato flesh sits atop mounds of rice just as tuna would.

Ocean Hugger's website says it transforms the tomato through a “proprietary process” that includes seasoning with soy sauce, sesame oil and sugar. The company also has an eggplant-based alternative to eel and is developing a carrot-based alternative to salmon.

Ahimi is a bit of a novelty, Lamothe allows, but she suggests that's what many sushi fans like.

“You eat with your eyes so they are looking for the whole package. (And) it was really important for our chefs to use products that are easy to use.”

In Toronto, acclaimed chef and restaurateur David Lee says he shies away from imitating meat or fish at his vegan restaurants, Planta, which include three eateries in Toronto and one in Miami.

Nevertheless, his menu includes a “ceviche” made with coconut instead of fish, mixed with onions, jalapenos, limes, coriander, chili peppers and sweet potato.

Then there's Planta's “ahi” watermelon, made with dehydrated watermelon infused with wakame and citrus, finished in soya sauce and topped with organic ginger.

“I'm not trying to say that you should eat this because it's better than tuna, but it's just an alternative,” says Lee, adding that it's a hit. “The ahi is the biggest seller, hands down.”

Still, Lee does see practical limits to spending an inordinate amount of time trying to innovate, even if it works.

He recalls their “carrot dog,” a faux hot dog that lasted two years on the menu, was a labour-intensive affair that involved a carrot that was brined, cooked, smoked and then seared.

While Lee insists that “at the beginning it was very successful,” he eventually “fell out of love” with it.

“The umami is very important and texture is very important and the depth of a dish is extremely important. How do we achieve that, how do we get that gold?” he says. “I mean trust me, there's been some hits, there's been some misses and we learn from our mistakes.

Montreal chef Ricardo Larrivee warns that calling something tuna when it's not could backfire if the goal is to convert anyone on the fence.

“If you make faux fish and it's not super-good, then you can have the opposite reaction: 'I tried it, I don't like it, I'll go back to fish,”' Larrivee says.

He suggests our attachment to seafood is at least partly psychological, and that the key to success is the right texture in its replacement.

“In the occidental way of cooking, if there's not the meat or the fish part, we always feel like we only had sides,” says Larrivee. “It's in our head, it's the way we think.”

For Friedrich, education only goes so far. Despite undeniable health and eco-concerns, he doubts most meat and fish eaters would ever go vegetarian without affordable alternatives.

“We really just need to change the meat instead of changing human nature,” says Friedrich.

“That's the focus of these alternatives: Let's give people everything that they like about meat but let's produce it in a far more efficient and less-damaging way.”

Much of the innovation in the faux-seafood sphere is occurring in the United States, where cell-based producers Finless Foods, Wild Type and Blue Nalu are experimenting with lab-grown salmon and tuna, and plant-based companies include Good Catch, Ocean Hugger, and New Wave Foods.

In Canada, Maple Leaf Foods said earlier this year it is investing heavily in plant-based products, although it's not clear if any of that will involve faux fish. Gardein's line of meatless foods include a breaded “fishless filet” and breaded “crabless cakes.”

The University of Guelph's Dana McCauley credits New Wave with an impressive soy-and-seaweed based “shrimp” that she sampled at an innovation meeting.

“If there was a time to launch this kind of product, it's definitely now and in the next few years,” says McCauley, associate director of new venture creation at the university's Research Innovation Office.

Given the state of our oceans, Friedrich suggests the survival of the planet may depend on it.

“This is how we save the world, essentially.”