How to Choose Fresh Tuna: What to Look For When Buying

Canned tuna is a convenient, lean source of protein that fits well into many diets. It’s affordable, shelf-stable, and versatile. However, not all canned tuna is created equal. To get the most benefit and minimise potential risks, pay attention to two important factors when you shop: mercury content and how the fish was caught and sourced.

1. MERCURY

Mercury concentrates more in larger, older predatory fish. As a result, the species of tuna matters. Choosing smaller tuna species or products labelled as tested for mercury helps reduce exposure. For most people who include tuna regularly in their diet, opting for lower-mercury varieties is a smart, practical choice.

Here are simple guidelines:

❌ Avoid albacore (white tuna) and yellowfin if you plan to eat tuna frequently. These varieties tend to have higher mercury levels compared with smaller tuna species.

✅ Prefer skipjack, tongol, or products marketed as “light tuna” — these are typically lower in mercury.

✅ If a different tuna variety is used, look for labels that indicate the product has been tested for mercury levels. Clear labeling gives you more confidence about safety, especially if you eat tuna several times a week.

If you’re open to other canned fish, consider sardines, anchovies, and mackerel. These options are nutrient-dense, rich in omega-3 fatty acids, and provide additional minerals like calcium, zinc, and iron — making them excellent alternatives or complements to tuna.

1. SUSTAINABILITY

Sustainability matters both for the health of ocean ecosystems and for the long-term availability of fish stocks. When choosing canned tuna, look for clear sustainability indicators on the label, and prefer fishing methods that have lower environmental impact.

✅ Favor products described as sustainably caught or sustainably sourced. Certifications such as the Marine Stewardship Council (MSC) are one way to identify more responsibly managed fisheries.

✅ Pole-and-line or single-line (rod-and-line) caught tuna generally have lower bycatch rates and less damage to marine habitats than large-scale net fishing. When these methods are listed, it’s a positive sign.

❌ Don’t be misled by vague claims like “wild caught.” While that term simply means the fish weren’t farmed, it doesn’t guarantee sustainable or low-impact fishing practices. Marketing language can be confusing; look for specific information about fishing method and reputable certifications instead.

Brand choice also matters to many shoppers. Some brands prioritise transparency about species, mercury testing, and sustainable fishing practices. For example, Wild Planet is commonly recommended for its clear sourcing and sustainability focus. Other regional or store brands may also offer responsibly sourced tuna—just check their labels for species, catch method, and certification details.

Practical tips when shopping:

• Read the can label carefully for species name (skipjack, tongol, albacore, etc.), catch method, and any sustainability certifications.
• If you eat tuna frequently, choose lower-mercury options and vary your protein sources to reduce cumulative exposure.
• Consider rotating in other canned fish like sardines or mackerel to boost omega-3 intake and diversify nutrients.
• When in doubt, choose brands that provide transparent sourcing information and avoid vague marketing claims.

By paying attention to species and sustainability, you can make smarter choices that support both your health and the oceans. Tuna can be a reliable part of a balanced diet when selected thoughtfully.