Can sushi be sustainable?
There are several theories about the origins of sushi. The one that places its origins in China holds that nigiri, sashimi and other forms of modern sushi originated from narezushi — a fermented food that entails stacking salted fish in wooden barrels for two years before they’re rinsed, dried and stored for yet another year in cooked rice. Before the advent of refrigeration, preservation was key.
It’s believed that narezushi made its way to Japan around the 8th century. Today, sushi is a global dish — it’s available from Michelin star restaurants around the world to grocery stores across the United States — that centers raw, fresh fish. The sushi market is only expected to grow, specifically by a forecasted $3.81 billion by 2028.
To meet this global demand, landlocked sushi restaurants fly their fish in from across the world. According to the USDA, the U.S. is Japan’s third largest seafood supplier of fish like salmon, cod, pollock and herring as well as broader seafood exports that account for $708 million worth of U.S. seafood exports. According to NOAA Fisheries statistics, the United States imported more than 79 percent of the seafood consumed domestically in 2020. In 2023, the U.S. imported $25.5 billion worth of seafood — the largest share of which, 14.1 percent, came from Canada followed by 13 percent and 10 percent from Chile and India respectively. The importing of fish to the global north from the global south, explains Dr. Daniel Pauly, principal investigator of the University of British Columbia’s SeaAroundUs initiative, is common. “Europe imports 80 percent of its fish,” he says, noting that both the U.S. and China also import “enormous quantities” of fish, amounting to a transfer of protein macronutrients from poorer countries that need it to richer ones that don’t in service of a luxury food item.
Pauly explains that the two main sources of sushi fish are tuna — specifically bluefin, a species whose population has shrunk to just 2.6 percent of its historic size thanks to fishing levels that are three times higher than what’s considered sustainable by the World Wildlife Fund — and salmon, the demand for which was largely invented by Norwegian salmon farmers to expand their market. Japan has the largest market for tuna, which is often ranched (meaning juvenile wild fish are caught, often in the Mediterranean, and subsequently fattened with sardines in captivity) while Europe, the U.K. and the U.S. generate the majority of the demand for salmon, the farmed varieties of which are also fed fish meal from an array of forage fish like sardines. “This is a waste of protein, a waste of valuable food that’s fed to carnivorous fish” that happens only because wealthier countries prefer eating salmon over the sardines that less-wealthy people in less-wealthy countries around the world prefer to eat.
Sushi has a sustainability problem. What can be done about it?
Pauly sees vegetarianism as a necessary step toward lowering the overall environmental impact of human food consumption, sushi included. “Humanity should gradually turn to vegetarianism because our footprint on the world and the land we need to produce feed for all of these animals is imposing an enormous toll on terrestrial biodiversity. The same thing with fish — it’s relatively healthy and everything, it began positively. But now, with very soon 10 billion of us, there is not enough fish to go around,” he says.
Pauly adds that we still have to be careful even with sushi’s non-fish elements. “If the vegetable matter that you will use to make sushi is coming from a place that doesn’t come from the clear cutting for forests [to plant] whatever plant you need, that would be a nice shift,” Pauly says. Take for example avocados, a common sushi ingredient in the U.S. They come largely from clear cut forests in Mexico’s Michoacan state and require large amounts of water to produce. Pauly also sees the potential in cell-cultured fish in addressing sustainability, but also other issues with fish. “Tuna sushi, for example, contains lots of mercury because, especially in bluefin, they’re old and big, so anything that could bypass this problem would be a solution — I think meat produced from cell cultures would be good,” Pauly says, not unaware that it will take technological advancement and investment for cell-cultured fish to truly become a viable alternative.
Hajime Sato, the chef and owner of Michigan’s Sozai Restaurant who has been practicing a sustainable sushi approach for 15 years, sees things differently.
Instead of putting time and energy into creating what he calls “fake tuna and fake salmon” from cell cultures, Sato points to his use of bycatch — the unwanted fish and other marine creatures caught during fishing for sought-after species — as a more sustainable option. “The only octopus we use is bycatch,” Sato says of his restaurant.
He is careful to never say that Sozai is 100 percent sustainable. “I cannot go to every fishery to make sure they’re doing good. I’m doing the best I can,” he says, by paying close attention to traceability, fish populations, fishing methods and farming practices. While Sato has since taken home a James Beard award for his work, when he first started approaching sushi more sustainably over a decade ago in Seattle, it wasn’t easy. Customers “literally said, ‘oh you don’t have this, you don’t have that, so I don’t come to your restaurant anymore’ and my sales went down by like 20 percent immediately,” Sato recalls.
But he stuck with it, individually studying the sustainability of various fish species and choosing to ship those that are perhaps less popular or well-known, but not overfished, to Michigan. “I get fish from the dock to my house FedEx overnight because some of the fish isn’t available around here, so I have to get a lot of fish directly otherwise it’s not available,” he says. He’s been able to cultivate a solid customer base that appreciates the unique seafood offerings that his more sustainable approach requires. While sales originally went down, they soon went up afterward, which for Sato is a testament to how interested people are in eating different fish varieties other than the same ones available everywhere else.
Sato references the seasonality of produce as a way to understand and approach sustainable sushi. “Some restaurants are adapting to what’s available during the season locally. You can apply that a little bit more to seafood also,” he says. “Ask the question to the chef, to the fishmonger, and they’ll tell you what’s local in season.” He thinks that if customers come into sushi restaurants asking about and requiring sustainability, that the industry will follow.
For Pauly, the logic falls apart on the population level. He’s doubtful that sustainability guidance on sushi is actually helps shift demand. The Monterey Bay Aquarium’s Seafood Watch program works to provide the public with science-based information on sustainable seafood, including its Sushi Consumer Guide. Pauly sees the document that breaks down sushi fish into best choices, good alternatives, and types to avoid as useless “magic cards.” “They basically do not have any effect on what the producer or the fishing companies do because they will always find consumers. The demand is high, they always find clients,” Pauly says. Along the lines of smoking bans and seatbelt laws, he thinks government regulation is the way. “The notion that voluntary influence will spread like the plague across the population and everybody’s going to follow is absolute nonsense and it has been empirically shown not to work,” he says.
In the meantime, Sato notes that sushi is defined by the use of vinegar rice, not fish. “When I was growing up in Japan, most of the sushi that we made at home was all vegetables, pickled vegetables and stuff,” he recalls. “That’s more traditional to me.” Just like with fish, vegetarian sushi still requires seasonality and, above all, a reverence for the bounty provided by nature.
Sato is currently growing Japanese eggplant at home and, when it’s ready to harvest, he plans to pickle it and make sushi out of it. “But I don’t want to do that in the middle of wintertime. Maybe in wintertime, [I’ll use] root vegetables — daikon radish, maybe turnip, stuff like that,” he says. “It doesn’t matter if it’s a vegetable or fish, you kill something when you harvest something. That means that you don’t waste things. Say thank you for it dying for us to eat, respect it, use it, and eat it.”
Top photo by KIYOSHI KASHIWANO/ Adobe Stock
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