Q: How much sushi is safe to eat?
A: You can't walk 3 feet in this town without tripping over a salmon roll or a slab of sashimi. But how much actual sushi-eating is safe for our bodies and the oceans?
For those of you not in the know, June 18 is International Sushi Day. (Yes, every food seems to have a day these days.) So there's no better time than now to take a second look at your sushi habits.
You may be muttering, "It's just a little sushi - how bad can it be?" The problem is, we're collectively eating a hell of a lot of little bites.
Our taste for bluefin tuna, for instance, has pushed Atlantic blue fin to the brink (populations have plummeted 68 per cent since the 70s). Our insatiable love for ecologically destructive lice-ridden farmed salmon is wreaking havoc on both coasts. (Flu-virus-laced salmon is also turning up in grocery stores; sign the change.org/salmonflu petition to stop it.) And I've had to give up unagi/BBQ eel rolls in recent years because they, too, are under threat (sigh).
The problem for our bodies, meanwhile, is that many of these morsels of sushi are also loaded with pollutants. It's the inescapable result of the world being our oyster and the ocean our collective industrial toilet. The neurotoxin methylmercury in fish comes largely from the drifting mercury emissions of coal plants.
So how much is safe to ingest? When GotMercury.org bought tuna sushi at 10 San Francisco Bay Area and 10 L.A. area restaurants last year, the samples averaged 0.721 ppm of mercury.
That actually flunks the mercury standard set for fish by Health Canada (.5 parts per million), except Health Canada realized that fresh/frozen tuna, shark, swordfish, escolar, marlin and orange roughy couldn't meet that standard, so they upped the mercury cap on those to 1.0 ppm. Hence, those fish are subject to "consumption advice" on HC's website: basically women of child-bearing years should eat no more than 150 grams, or 5 ounces, a month - in other words, no more than a few pieces of, say, tuna sashimi, five individual pieces of nigiri or a couple of tuna rolls a month.
Kids between five and 11 should eat no more than 125 grams per month (4.5 ounces) of these high-risk fish. Tots under four should eat no more than 75g (2 ounces, i.e., two or so pieces of tuna nigiri).Swordfish is one of the worst offenders for mercury, though I was floored that my fave sustainable sushi, mackerel (not just king mackerel) is also high in mercury.
Health Canada seafood testing found the highest levels of PCBs in farmed salmon, though HC says it's only really concerned about PCB exposure in those who eat large amounts of sports fish. You can generally minimize your intake of all sorts of persistent chemicals, including PCBs and flame retardants, by minimizing your intake of all fatty foods, including fatty fish like farmed salmon and fish skins.
So as my sushi-lovin' friend asked me earlier today, what seafood can we eat, besides small fish like anchovies and sardines? You should be in the clear with BC black cod/sablefish (sushi name: gindara), farmed rainbow trout, farmed arctic char (sushi name: iwana), wild Alaskan salmon (sake), BC albacore tuna (shiro maguro, lower mercury option), BC spot prawns (ama-ebi), striped bass (suzuki), squid (ika), farmed oysters (kaki) and, if you can stomach it, Seafood Watch says Canadian sea urchin (aka uni) now gets the green light, too.
See Seachoice.org's printable sustainable sushi guide. EDG.org/Seafood's sushi guide also indicates fish low in contaminants, and Sierra Club's got a handy app called Safe Sushi that tells you how much mercury is in your sashimi.
Unlike the West Coast, Toronto has few sushi joints with sustainable seals of approval, so tell your local sushi boîte to get movin' and connect with oceanwise.ca. Happily, grocery-counter-based Bento does offer some Seachoice-approved tuna and crab.
If you're unsure and your local sushi joint can't answer questions on how or where fish is caught, you're best off sticking to avocado/cucumber rolls.