Some fish naturally accumulate much higher levels of mercury than others because they are large predators that live for many years. Species such as bluefin tuna, swordfish, orange roughy, and Chilean sea bass are often cited as examples where consumers may wish to limit or avoid frequent consumption, particularly pregnant women and young children. Many of these species have also experienced significant fishing pressure over the years, making sustainable management especially important.

Seafood production methods also vary widely. Some imported shrimp, farmed salmon, tilapia, and catfish are produced responsibly, while others may come from operations associated with poor environmental practices, excessive antibiotic use, habitat destruction, or labor concerns. Because standards differ by country and producer, the source of the seafood often matters as much as the species itself.

Fortunately, there are alternatives that can support both healthier diets and more sustainable fisheries. Wild Alaskan salmon, Pacific cod, U.S. wild-caught shrimp, mussels, sardines, anchovies, and responsibly farmed trout are frequently recognized as lower-mercury or environmentally preferable choices, depending on where and how they are harvested. Looking for reliable sustainability certifications and checking the seafood’s origin can help consumers make more informed decisions.

No single meal will transform the world’s oceans, but consistent choices influence markets over time. Every purchase encourages suppliers, fisheries, and restaurants to respond to consumer demand. Choosing seafood from well-managed fisheries, diversifying the species you eat, and avoiding products with uncertain origins are practical steps that support healthier oceans. Small decisions made repeatedly may seem insignificant on their own, but together they contribute to protecting marine ecosystems for future generations.