Overfishing: Populations so depleted that continued fishing threatens the species' survival. Examples include Atlantic halibut, orange roughy, and Atlantic bluefin tuna.
Destructive fishing methods: Bottom trawling, longlining, and purse seining can damage seafloor habitats and kill non-target species (bycatch).
Farming practices: Poorly managed farms can pollute waters, spread disease, and rely on wild-caught fish for feed.
2. Health Concerns
Mercury contamination: Large, long-lived predatory fish accumulate high levels of mercury, which is toxic to humans.
PCBs and other pollutants: Some fish, especially farmed varieties from certain regions, contain harmful industrial chemicals.
Parasites: Some fish, like swordfish, are known to carry visible parasites that, while killed by cooking, can be off-putting.
3. Ethical & Economic Concerns
Mislabeling: Red snapper, grouper, and other high-value fish are frequently replaced with cheaper substitutes.
Illegal fishing: Some fish, like Chilean sea bass, have been historically harvested illegally.
Animal welfare: Certain fishing and farming practices raise ethical concerns.
10 Fish to Avoid (And What to Eat Instead)
Let me walk you through the fish you should steer clear of, the reasons why, and the smarter swaps.
1. Atlantic Halibut
Why it's bad: Atlantic halibut populations have been so severely overfished that scientists estimate the species won't rebound until 2055. Bottom trawling, the method used to catch them, also damages the seafloor and kills non-target species. Additionally, Atlantic halibut live up to 50 years and accumulate high levels of mercury .
The health risk: High mercury levels can cause neurological and behavioral issues, especially in pregnant women and children.
What to order instead: Pacific halibut. Wild Pacific halibut populations are healthy, thanks to sustainable fishing practices off the coasts of Alaska, Washington, and British Columbia .
2. Atlantic Bluefin Tuna
Why it's bad: Bluefin tuna populations are critically endangered due to decades of overfishing. The species is prized for sushi (especially fatty otoro and chu-toro), which drives high demand and high prices. Fishing methods like purse seining and longlining also result in massive bycatch of sharks, turtles, and marine mammals .
The health risk: Bluefin tuna has the highest mercury levels of any tuna species .
What to order instead: Alaskan wild-caught salmon or Albacore tuna (American or Canadian, not imported) caught while young .
3. Atlantic Cod
Why it's bad: Cod is a British and American classic, but UK cod stocks are doing poorly, and even Icelandic stocks are under pressure. The Marine Conservation Society has downgraded cod ratings, pointing to mounting pressure on familiar favorites .
What to order instead: European or UK-caught hake. Hake offers the same clean, flaky texture as cod but comes from healthier populations .
4. Chilean Sea Bass (Patagonian Toothfish)
Why it's bad: Chilean sea bass is a delicacy with a dark secret. Most of it has been harvested illegally, and populations are in such bad shape that Greenpeace estimates the species could be commercially extinct within five years without intervention. The fish is also high in mercury .
What to order instead: US hook-and-line-caught haddock offers the same texture and feel .
5. Orange Roughy
Why it's bad: Orange roughy takes 20-40 years to reach maturity and reproduces very late in life, making it extremely vulnerable to overfishing. Populations collapsed in the 1990s and have been slow to recover. It also has high mercury levels .
The mislabeling problem: Orange roughy sometimes appears in grocery freezers mislabeled as "sustainably harvested." No orange roughy fisheries are considered well-managed or certified by the Marine Stewardship Council .
What to order instead: Yellow snapper or domestic catfish offer similar texture .
6. Shark
Why it's bad: Shark populations are under extreme pressure from finning—the practice of removing fins (often while the shark is still alive) for shark fin soup. An estimated 100 million sharks are killed annually. Shark meat is also high in mercury, and longlining methods result in heavy bycatch .
The ecosystem impact: With fewer sharks, their prey (like rays and jellyfish) have exploded in numbers, depleting scallops and other fish humans rely on .
What to order instead: Pacific halibut or Atlantic mackerel .
7. Red Snapper
Why it's bad: Red snapper is problematic for two reasons. First, population sustainability depends entirely on location—some stocks are healthy, others are not. Second, mislabeling is rampant. One study found that 90% of red snapper samples from menus and grocery stores were actually other species (including tilapia) .
How to protect yourself: If you order red snapper, ask for it skin-on. The distinctive red skin doesn't fully fade during cooking, helping you verify you're getting what you paid for .
What to order instead: US hook-and-line-caught haddock or Pacific halibut.
8. Imported Catfish (and Swai)
Why it's bad: US farmed catfish is excellent and sustainable. However, Vietnamese-raised swai (a distant, cheaper relative) was once routinely labeled as catfish. While regulations have changed, the substitution may still occur in restaurants .
The health risk: Catfish from some countries may contain antibiotics banned in the US, and farming practices can pollute local waters.
What to order instead: US farmed catfish or domestic tilapia from certified sources. Seafood Watch recommends tilapia from Ecuador and Peru; avoid tilapia from China .
9. Eel (Unagi)
Why it's bad: Wild eel populations are in severe decline. Eel farming doesn't solve the problem—it requires 2.5 tons of wild fish feed to produce 1 ton of eels, putting pressure on wild fish populations. Eel farms also destroy wetlands and can release diseases into wild habitats .
What to order instead: Atlantic or Pacific caught squid offers a similar chewy texture and can be prepared in many of the same ways .
10. Swordfish
Why it's bad: This is one fish that restaurant workers themselves avoid. Swordfish are known to carry a high number of visible parasites (nematodes and anisakis worms). While cooking kills the parasites, the visual is so off-putting that even chefs often skip ordering it .
The health risk: Swordfish is also high in mercury. Warming ocean waters are increasing parasite prevalence in swordfish populations .
What to order instead: Pacific halibut or yellow snapper.
Bonus: Fish to Avoid for Environmental Reasons
Atlantic Flatfish (Flounder, Sole, Atlantic Halibut)
This group of fish—including flounder, sole, and Atlantic halibut—has been overfished since the 1800s. Some populations are as low as 1% of sustainable levels .
What to order instead: Pacific halibut or domestically farmed catfish or tilapia .
Caviar (from beluga and wild-caught sturgeon)
Caviar from beluga and wild-caught sturgeon comes from fish that take a long time to mature, so populations recover very slowly. Dam building that pollutes waterways is an additional threat .
Sustainable Swaps at a Glance
| Instead of This... | Choose This... |
|---|---|
| Atlantic halibut | Pacific halibut |
| Atlantic bluefin tuna | Alaskan wild salmon or American/Canadian albacore tuna |
| Atlantic cod | European hake or Pacific cod (from healthy stocks) |
| Chilean sea bass | US hook-and-line-caught haddock |
| Orange roughy | Yellow snapper or domestic catfish |
| Shark | Pacific halibut or Atlantic mackerel |
| Red snapper | US hook-and-line-caught haddock or Pacific halibut |
| Imported catfish/swai | US farmed catfish or Ecuador/Peru tilapia |
| Eel (unagi) | Atlantic or Pacific squid |
| Swordfish | Pacific halibut or yellow snapper |
| Imported farmed shrimp | US farmed shrimp or MSC-certified wild shrimp |
How to Be a Savvy Seafood Consumer
Let me give you practical tips for ordering seafood confidently.
Ask questions. "Where is this fish from?" "Is it wild or farmed?" "How was it caught?" A knowledgeable server or chef should be able to answer.
Look for eco-labels. The MSC (Marine Stewardship Council) blue tick certifies sustainable wild-caught seafood. The ASC (Aquaculture Stewardship Council) certifies responsible farmed seafood .
Know your seasons. Some fish have specific seasons when they're most abundant and sustainable.
Trust your senses. Fresh fish should smell like the ocean, not "fishy." If a restaurant smells off, trust your instinct.
Consider lesser-known species. Hake, pollock, saithe (coley), and rope-grown mussels are excellent, sustainable options that are often more affordable .
Don't be afraid to speak up. If a restaurant can't tell you where their fish came from, consider ordering something else.
Frequently Asked Questions
What's the most sustainable fish to order?
Rope-grown mussels and farmed oysters are among the most sustainable options—they don't need any feed or chemicals, as they get everything they need from the sea .
Is farmed salmon bad?
It depends. Wild Atlantic salmon populations are not doing well. Some farmed salmon is rated poorly due to environmental impacts. Organic and Scottish ASC-certified farmed salmon are better choices. UK freshwater farmed rainbow trout is an excellent alternative .
What about canned tuna?
Skipjack tuna is generally more sustainable than albacore. Look for "pole-and-line caught" or MSC-certified options. Better yet, swap tuna for anchovies caught in the Bay of Biscay or MSC-certified sardines .
Is tilapia safe to eat?
Tilapia from Ecuador and Peru is recommended by Seafood Watch. Avoid tilapia from China due to poor farming practices and potential health risks .
Why should I avoid imported shrimp?
Shrimp farming can destroy mangrove forests and use antibiotics banned in the US. Look for US-farmed shrimp or MSC-certified wild shrimp.
A Smarter, More Sustainable Plate
Here's what I want you to take away from this guide.
You don't have to give up seafood to be a responsible consumer. You just need to be informed. Swap Atlantic halibut for Pacific. Choose hake over cod. Try anchovies instead of tuna. Order rope-grown mussels—they're delicious, sustainable, and often cheaper.
Every dollar you spend on seafood is a vote. Vote for healthy oceans. Vote for sustainable fisheries. Vote for your own health.
And when you're at a restaurant, don't be afraid to ask questions. A good restaurant will be proud to tell you where their fish comes from.
Now I'd love to hear from you. Have you ever been served mislabeled fish? What's your go-to sustainable seafood choice? Drop a comment below – I read every single one.
And if this guide helps you make better choices at restaurants, please share it with a friend who loves seafood. A text, a link, a conversation. Good information is the best recipe. 🐟🌊💙
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