Which grocery store fish species contain the most microplastics?

What's actually in it

Microplastics are in every ocean, river, and lake. Fish eat them directly — mistaking plastic particles for food — or accumulate them through the fish they eat. Predatory fish at the top of the food chain accumulate more. Filter feeders like mussels and anchovies concentrate them from the water.

Most microplastics end up in fish gut tissue, which is removed before eating. But some embed in muscle tissue — the part you eat — and can't be cleaned or cooked out.

What the research says

A 2026 study in Mar Pollut Bull analyzed microplastic contamination across 30 commercially important fish species. Every single species tested positive. Polymer types varied by species, with polyethylene and polystyrene being the most common — the same plastics in food packaging and disposable containers.

The study calculated human health risk from eating these fish and found meaningful dietary exposure to microplastics — particularly from regular consumption of higher-contamination species. Smaller fish eaten whole (like sardines) and shellfish carry more risk per serving than large fish where guts are removed.

Eating some fish is still worthwhile for omega-3s, but varying your protein sources reduces microplastic exposure. Avoid eating fish organs and guts. Check out non-toxic kitchen alternatives for filtered water and food storage that reduces your overall microplastic exposure.