Mercury is a metal that originates on land, then works its way into our waters where it's absorbed by smaller fish. However, mercury does not dissolve or break down, but rather accumulates as larger, predatory fish eat down the food chain.
When humans consume mercury-laden fish, the mercury is absorbed into our systems, acting as a toxin that can impact brain function and development. Those who are pregnant should specifically stay away from food sources that could contain mercury.
Use the following information to create a more sustainable and safe roll:
- Tuna is the most common source of mercury exposure, because Americans consume it more than other mercury-laden fish. The Environmental Defense Fund has reported that bluefin tuna have some of the highest mercury levels.
- Albacore tuna is known as shiro maguro when prepared for sushi. Order troll- or pole-caught albacore as these methods catch younger tuna with lower mercury levels.
- Other alternatives include freshwater Coho salmon, wild-caught Masago (smelt roe) and Atlantic mackerel.
- Take advantage of the Monterey Bay Aquarium Seafood Watch program. Its recommendations are science-based, peer-reviewed and use ecosystem-based criteria. Download its sushi guide (pdf).