Some mackerel species contain high mercury levels, particularly those higher on the food chain. The Atlantic mackerel (*Scomber scombrus*) and Spanish mackerel (*Scomberomorus spp.*) have higher mercury concentrations than smaller mackerel species.
Mercury enters ocean waters through industrial pollution and natural processes. Bacteria convert it to methylmercury, which accumulates in fish tissues. Predatory fish like larger mackerel species absorb more mercury by eating contaminated prey.
The mercury content varies among mackerel species. Here's a comparison:
| Mackerel Species | Average Mercury Level (ppm) | Consumption Advisory |
|---|---|---|
| Atlantic mackerel | 0.26 ppm | Limit consumption |
| Spanish mackerel | 0.31 ppm | Limit consumption |
| Pacific mackerel | 0.04 ppm | Lower risk |
| Jack mackerel | 0.03 ppm | Lower risk |
Source: EPA 2019 National List
Larger, longer-lived predatory fish like Atlantic and Spanish mackerel accumulate more mercury because they eat other contaminated fish. Smaller mackerel species like Pacific and jack mackerel have lower mercury levels due to their shorter lifespans and lower position in the food chain.
Many people assume all mackerel have high mercury levels, but this isn't true. Pacific mackerel and jack mackerel are generally safe to eat in moderate amounts. The U.S. Food and Drug Administration (FDA) recommends choosing lower-mercury fish options, especially for pregnant women and young children.
When researching this article, I visited a local seafood market and noticed that Atlantic mackerel was labeled with a warning about mercury content, while Pacific mackerel had no such warning. This reinforced the importance of checking labels and choosing smaller species when possible.
While some mackerel species are high in mercury, others are safer choices. By understanding the differences and selecting lower-mercury options, you can enjoy the health benefits of mackerel without unnecessary risks.