Seafood can make an excellent addition to a diet. Fish—which is often low in unhealthy fat (like saturated fat) and high in healthy fat (like omega-3 fatty acids)—in particular makes for a healthy meal. But not all fish is created equally. Some catches have become highly contaminated with metals and dangerous chemicals, meaning they pose legitimate health threats. Others shouldn’t be eaten because doing so threatens delicate ecosystems.
Here’s a rundown of ten types of fish to buyer beware…
1. Wild Chilean Sea Bass
Stop by any fancy restaurant and chances are you’ll find Chilean sea bass on the menu. Given the Chilean sea bass’ rich flavor, it’s no surprise that this type of fish is in high demand around the world. But you may want to think twice about ordering it next time you sit down for a nice meal.
Because of its appeal, overfishing has become a serious problem in a number of areas—including the Crozet Islands, Prince Edward and Marion Islands, and Chile. Chilean sea bass can also be very high in mercury (when it’s not labeled by the Marine Stewardship Council (MSC), known for sustainable, low-mercury seafood), which is why health experts, including a 2014 study published in the journal PLOS ONE, recommend humans eat it only once or twice per month.