The healthiest seafood options in 2026 are generally characterized by high levels of omega-3 fatty acids, high-quality protein, and low levels of environmental contaminants like mercury. Wild-caught Alaskan salmon remains the "superstar" due to its rich concentrations of Vitamin D, B12, and selenium, which support heart and brain health. Small, oily fish such as sardines, Atlantic mackerel, and herring are also top-tier choices; because they are lower on the food chain, they accumulate significantly less mercury while providing massive amounts of calcium and healthy fats. Rainbow trout and Arctic char are excellent sustainable alternatives that offer a similar nutrient profile to salmon but with a milder flavor. For those seeking lean protein, Pacific cod and Alaskan pollock are low-calorie favorites that are high in iodine. Additionally, shellfish like oysters and mussels are nutritional powerhouses, providing more zinc and iron per serving than almost any other food source. To maximize health benefits, the American Heart Association recommends two 3-ounce servings of non-fried fatty fish per week, while avoiding high-mercury species like shark, swordfish, and king mackerel.