10 Fish You May Want to Think Twice About Ordering at a Restaurant

Ordering seafood can be a great way to enjoy a flavorful meal while adding valuable nutrients to your diet. But not every fish is the same. Some species can contain higher levels of mercury, while others may raise sustainability concerns depending on where and how they are caught or farmed.

That doesn’t mean these fish must always be avoided. The better approach is to understand the differences and make informed choices when possible.

1. Bluefin Tuna

Bluefin tuna is prized for its rich flavor and is especially popular in sushi restaurants. However, larger, long-lived predatory fish can accumulate more mercury over time.

For people who eat tuna regularly, choosing lower-mercury varieties and limiting portions can be a more practical approach than making tuna an everyday meal.

2. Swordfish

Swordfish is another large predatory fish that can contain relatively high levels of mercury. It is best enjoyed occasionally rather than as a frequent seafood choice, particularly for people who need to be more cautious about mercury exposure.

3. Shark

Sharks are also long-lived predators that can accumulate mercury in their tissues. Because of this, shark is generally considered a fish to eat less frequently.

Before ordering it, diners may want to consider alternatives such as salmon, trout, or smaller fish that tend to have lower mercury levels.

4. King Mackerel

King mackerel is a flavorful fish, but it is among the species commonly associated with higher mercury levels. If you’re looking for seafood to eat regularly, lower-mercury choices may be a better option.

5. Orange Roughy

Orange roughy has a mild flavor and firm texture, but it is a long-lived species. Its longevity means mercury can accumulate over time, making it another fish better suited to occasional consumption.

6. Marlin

Marlin is another large predatory fish that may contain elevated mercury levels. If it appears on a restaurant menu, consider how often you eat similar high-mercury species throughout the week.

7. Chilean Sea Bass

Chilean sea bass is popular because of its rich, buttery texture. However, sustainability can vary significantly depending on the fishery and certification behind the product.

Rather than automatically avoiding it, diners interested in sustainability can ask where the fish came from and whether the restaurant follows responsible sourcing practices.

8. Imported Shrimp

Shrimp is one of the most popular seafood choices in restaurants, but its environmental impact can differ substantially depending on whether it is wild-caught or farmed and where it comes from.

Instead of assuming that all imported shrimp is problematic, ask about its origin and sourcing practices when that information is available.

9. Farmed Salmon

Farmed salmon is not inherently unsafe or unhealthy. In fact, salmon is an excellent source of protein and omega-3 fatty acids.

However, farming methods vary, and some diners may prefer products certified by organizations that evaluate environmental and production standards. Wild-caught salmon can also be an alternative when available.

10. Tilapia

Tilapia is generally a mild, affordable source of protein, but its nutritional profile and environmental considerations can vary depending on how it is produced.

The most useful question isn’t simply whether tilapia is “good” or “bad.” Instead, consider the source, preparation method, and overall balance of your meal.

What Are Better Seafood Choices?

If you’re looking for seafood that is generally lower in mercury, smaller fish can be excellent options. Sardines and anchovies are examples of smaller species that provide nutrients while typically containing less mercury than large predatory fish.

Salmon and trout can also be nutritious choices, while mussels and other shellfish may offer an additional option depending on local sourcing and dietary needs.

When sustainability matters to you, look for information about where the seafood was caught or farmed. Certifications and responsible sourcing programs can also provide useful guidance.

The Best Choice Isn’t Always About Avoiding a Specific Fish

Seafood choices don’t have to be complicated.

Instead of labeling an entire species as something you should “never” eat, consider three factors: mercury levels, sourcing, and how frequently you eat it.

A fish that may not be ideal as an everyday choice can still be enjoyed occasionally. At the same time, choosing a wider variety of seafood can help reduce reliance on a small number of heavily consumed species.

The next time you’re studying a restaurant menu, take a moment to consider what’s behind the name of the fish. A little information about mercury, origin, and sourcing can help you choose a meal that fits both your preferences and your dietary needs.