That perfectly seared piece of fish may look like the healthiest choice on the menu, but seafood quality involves much more than appearance. Fish can be an excellent source of protein and omega-3 fatty acids, yet some varieties can also raise concerns about mercury levels, environmental impact, fishing methods, or farming conditions. Knowing what you’re eating and where it comes from can help you make more informed choices.

Large, long-lived fish are generally the ones that deserve the most caution because they can accumulate more mercury over time. Species such as bluefin tuna, swordfish, orange roughy, and Chilean sea bass may contain higher mercury levels, while some also face sustainability concerns depending on how and where they are caught. Farmed seafood can vary as well. Shrimp, salmon, tilapia, and catfish may come from farms with very different environmental and production practices, so the source matters.

Fortunately, there are plenty of nutritious alternatives. Wild Alaskan salmon, Pacific cod, U.S.-caught wild shrimp, mussels, sardines, anchovies, and responsibly farmed trout can offer good nutritional value while often presenting lower mercury or sustainability concerns. Seafood guides and reputable sustainability certifications can also help you determine which options are better choices when shopping or ordering at a restaurant.

Ultimately, choosing seafood thoughtfully can benefit both your health and the oceans. You don’t have to avoid seafood altogether—in fact, fish can be an important part of a balanced diet. The goal is simply to choose a variety of lower-mercury options and, when possible, seafood from well-managed fisheries or responsible farms. One meal won’t transform the future of the oceans, but consistent choices can help support healthier marine ecosystems and more sustainable seafood practices.