Seafood Sustainability Calculator

Seafood is one of the richest dietary sources of omega-3 fatty acids (DHA and EPA), which support heart health, brain function, and reduce inflammation. Federal nutrition guidelines recommend eating at least 2 servings of seafood per week for most adults. However, the type and frequency matter greatly due to mercury and sustainability concerns.

The general recommendation is 8 oz of seafood per week for adults. Pregnant women, nursing mothers, and young children should target 8–12 oz per week of low-mercury choices. This calculator helps you track not just quantity but the quality of your choices in terms of mercury exposure and omega-3 benefit.

Mercury is a naturally occurring element that also enters the environment through industrial pollution. It converts to methylmercury in water, which accumulates in fish tissue through a process called bioaccumulation. Larger, longer-lived predatory fish like shark, swordfish, and bigeye tuna tend to have the highest mercury concentrations.

No — pregnant women and children should not avoid seafood entirely, as omega-3s are critical for fetal brain development and child growth. However, they should strictly avoid high-mercury species (shark, swordfish, king mackerel, tilefish, bigeye tuna) and stick to low-mercury options like salmon, sardines, shrimp, and pollock, limiting intake to 8–12 oz per week.

Sustainable seafood comes from sources — either wild-caught or farmed — that are managed to maintain healthy fish populations and minimize environmental damage. Factors include fishing methods, bycatch rates, habitat impact, and whether stocks are being harvested faster than they can reproduce. Certifications like MSC (Marine Stewardship Council) and ASC (Aquaculture Stewardship Council) indicate sustainable sourcing.

Beyond mercury, seafood can contain PCBs, dioxins, and other persistent organic pollutants, particularly in farmed fish fed fishmeal-heavy diets or fish caught near industrial areas. Varying your seafood choices across different species and sourcing regions reduces your cumulative exposure to any single contaminant.

Vegetarians and vegans can get alpha-linolenic acid (ALA) from flaxseeds, chia seeds, walnuts, and hemp seeds. However, the conversion of ALA to the more beneficial DHA and EPA forms is inefficient. Algae-based omega-3 supplements are the most direct plant-based source of DHA and EPA, since fish themselves obtain these fatty acids from algae.

Supplements can be a useful alternative or addition, especially for those who don't eat fish regularly or are pregnant. However, whole food sources of omega-3s come packaged with protein and other micronutrients that supplements don't provide. Consult your healthcare provider about whether supplementation is appropriate for your specific health needs.