Want Sustainable Sushi? Follow the 4-S Rule


By Casson Trenor

I was recently interviewed by a CNN team who wanted to know about sustainability in the sushi industry. This video clip is me explaining what I call the “4-S rule” – a simple if somewhat crude guide to eating in a more sustainable fashion at the sushi bar (oh, and a small correction to CNN’s byline – I am a co-founder of Tataki Sushi Bar, but I don’t actually own the restaurant.)

Basically, there are four adjectives, each starting with the letter S, that form the eponymous rule. If you bear these descriptors in mind while you order, you can markedly diminish your environmental footprint at that meal. It’s not a perfect system – there are exceptions to each of the four “S” words – but by and large, it will help you eat sushi more sustainably.

SMALL: Smaller fish are generally lower on the trophic scale – the food chain – grow more quickly, die younger, and breed in larger numbers. These biological survival tactics are used by many fish to help them withstand heavy predation — they play the numbers game and simply create as many offspring as possible, so a few manage to escape the yawning maws of hungry predators. In essence, these fish that are designed to be eaten. Their physiology and population dynamics are generally more resilient to fishing pressures and protein demands than top-of-the-food-chain carnivores like large tunas, swordfish, and sharks. (And smaller fish generally have less mercury in their systems than apex predators.)

Examples: Sardines (iwashi), skipjack tuna (katsuo), horse mackerel (aji)

SEASONAL: Seasonality is key to sustainability. If we are to reduce our carbon dependency and rekindle our connection to the ocean, we need to be more aware of where we are and what time of year it is when we order our fish. A good rule of thumb is to order off the specials board rather than the laminated menu when possible – any items on a year-round menu are unlikely to be sourced on a basis of seasonal awareness. (It was our demand that certain intrinsically seasonal products be available to us year-round that gave rise to environmental missteps like conventional salmon farming.) Seasonal fish also offers us the added opportunity to take advantage of seasonal vegetables and fruits, which innovative chefs often incorporate into their specials.

Examples: Wild salmon (sake), Dungeness crab (kani), spot prawns (ama ebi),

SILVER: Perhaps the most surprising: Eat sushi served with silver skin. This category of fish is known as hikari mono in Japanese, and contains mackerels, halfbeaks, shads, and similar fish. They tend to be loaded with omega-3s, are as low in mercury, and can be sourced from many well-managed fisheries. An added bonus is that the hikari mono are some of the most treasured fish in the repertoire of a traditional sushi chef; a menu featuring these items will often prove to be an unforgettable culinary experience.  I highly encourage all sushi-goers to explore the world of hikari mono — you just may find your new absolute ultimate all-time favorite sushi item.

Examples: Mackerel (saba), Pacific saury (sanma), Spanish mackerel (sawara),

SHELLFISH: I’m speaking specifically of bivalves and mollusks. Bivalve and mollusk aquaculture has sound environmental benefits, and tends to involve relatively low-impact farming methods when compared to other types of fish farming. As filter-feeders, animals like clams, scallops, and oysters can be grown without the use of any additional feed. This reduces their dependence on marine resources and eliminates the kind of inefficient protein use that we find in operations like hamachi and unagi ranches.  These mollusks also grow quickly, and can be raised in cages and bags that require no dredging or other types of seabed alteration during harvest.

Examples: Oysters (kaki), mussels (muurugai), geoduck (mirugai)

That’s about the size of it. Small, seasonal, silver, and shellfish – a quick-and-dirty road map to a more eco-groovy sushi experience. There are, as I mentioned earlier, numerous exceptions to this rule, but it serves as a fairly reliable touchstone for those who are interested in shifting their sushi dining habits towards a more sustainable paradigm.

Oh, and one final quip: as it happens, the letter S occurs exactly four times in the term “sustainable sushi.” Remember that to keep the 4-S rule in mind.

[Pole-caught Pacific skipjack tuna (katsuo) served nigiri-style with mountain burdock (gobo), perilla leaf (shizo).  Plated by Chef Kin Lui of Tataki Sushi Bar. Photo © 2010 www.sustainablesushi.net]

Posted in Japanese, Seafood


  1. MeredithCooks said...

    I was in San Francisco in March and went to to Tataki. I really enjoyed it!

  2. Anonymous said...

    Thanks for featuring this, Mark. We sushi chefs and lovers of the ocean greatly appreciate this!

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