Is Your Seafood Contaminated? The Truth About Microplastics in Fish

When we think about plastic pollution, images of floating bottles and oceanic garbage patches often come to mind. However, the real issue might be less visible and more insidious—microplastics infiltrating the seafood we consume.

Recent studies have revealed alarming statistics: microplastics were found in 180 of 182 seafood samples, 99% of the tested seafood.¹ Another study along the Visakhapatnam coast detected microplastic particles in 100% of the 100 marine specimens analyzed, encompassing fish, shrimp, crabs, and squid.²

This isn’t just a marine problem; it’s a human one. As microplastics accumulate in marine life, they make their way up the food chain, potentially ending up on our plates. Scientists are still studying the full health effects, but there’s growing concern that microplastics could interfere with hormones and potentially play a role in the development of cancer.

This post will examine how microplastics end up in fish, what that means for human health, and where the research stands today. We’ll also discuss practical ways to reduce exposure and contribute to the bigger solution.

How Do Microplastics End Up in Fish?

Microplastics don’t just appear in fish out of nowhere—they get there through a chain of pollution that starts with us. Tiny particles are released into the environment every time plastic breaks down, whether a water bottle is tossed on the beach or microfibers are shed during laundry. Once in rivers, lakes, or oceans, these particles become part of the aquatic food system.

In marine ecosystems, fish are exposed to microplastics in a few key ways:

Direct ingestion: Some fish mistake floating plastic particles for food, especially species that feed near the surface or on plankton. These plastics can look like fish eggs or other natural prey.
Trophic transfer: Even fish that don’t eat plastic directly can still ingest it by eating smaller organisms that have it. In other words, it moves up the food chain.
Contaminated sediment and water: Bottom-dwelling species like flounder or shellfish can be exposed through sediments where microplastics accumulate. Filter feeders like mussels and oysters absorb particles directly from the water as they eat.

Human activity is the root cause. Wastewater treatment plants can’t catch everything, especially microfibers from synthetic clothing. Fishing gear, food packaging, tire dust, and microbeads from cosmetics all contribute to microplastic pollution that eventually enters aquatic ecosystems.

Once microplastics are in the water, fish don’t stand much chance. And as long as we keep producing and discarding plastic at our current rate, the problem will only grow.

Prevalence of Microplastics in Fish and Seafood

Microplastics have made their way into seafood at an unsettling scale. Studies worldwide continue to find plastic particles in many marine species, everything from shrimp and herring to deep-dwelling fish like lingcod. And we’re not just talking about trace amounts.

A 2024 study published in Frontiers in Toxicology analyzed 182 seafood samples from the U.S. West Coast, including species like black rockfish, lingcod, Chinook salmon, Pacific herring, Pacific lamprey, and pink shrimp. Researchers found that 180 of the 182 samples contained anthropogenic particles, such as microplastics and microfibers.³

These findings indicate that microplastic contamination is widespread in seafood, affecting both wild-caught and retail-purchased products. Even after cleaning and preparing seafood, microplastics may still be present in our consumed portions.

Microplastic contamination isn’t limited to one region or type of fish. It varies by species, habitat, feeding behavior, and organism size. Plankton-feeding fish are particularly vulnerable because they often mistake microplastics for food. Researchers sometimes measure the number of microplastics per gram of tissue to track how concentrated the exposure is.

This points to a broader truth: seafood has become one of the most consistent routes of human exposure to microplastics. Whether wild-caught or farmed, few marine species are escaping this problem entirely.

What Happens When Humans Eat Contaminated Fish?

So if fish eat plastic… what happens when we eat the fish?

Researchers around the world are racing to answer that question. While the full impact on human health is still being studied, early findings are enough to raise concern, especially regarding repeated exposure over time.

When we consume seafood that contains microplastics, we’re not just eating plastic fragments. We’re also potentially ingesting the chemical additives used in plastic production (like bisphenols and phthalates) and toxic substances that plastic absorbs in the water—think pesticides, heavy metals, or industrial chemicals like PCBs.

Some studies suggest these particles can pass through the gastrointestinal tract without absorption. But others have found nanoplastics—even smaller than microplastics—may be able to cross into human tissues and organs, including the liver, spleen, and bloodstream.³ That opens the door to possible immune responses, hormone disruption, and inflammation.

It’s not just about how much seafood you eat, but what kind. Whole organisms like mussels and oysters are more likely to carry microplastics in their edible portions. At the same time, filleted fish may contain less, depending on whether microplastics have migrated from the gut into other tissues.

We’re still missing long-term human studies, but lab research has linked plastic exposure to a variety of potential health concerns:

Endocrine disruption (hormone imbalance)
Oxidative stress
Changes to gut microbiota
Possible links to cancer or reproductive issues in animal studies

In short, eating contaminated fish may not cause immediate harm. Still, it adds to a growing body burden of plastic-related chemicals, especially concerning populations that rely heavily on seafood for protein.

Human Exposure and Consumption Risks

Eating fish and seafood is one of the most direct ways microplastics enter our bodies. But how much are we ingesting—and what does that mean for our health?

Recent research from Cornell University mapped microplastic ingestion across 109 countries and found that people in the United States consume around 2.4 grams of microplastics every month, mostly from seafood and other aquatic foods.⁴

That may not sound like much—until you realize it’s roughly the weight of a credit card. And that’s not a one-time thing. It adds up month after month, year after year, especially for people who eat more seafood or consume whole animals like oysters, sardines, or shrimp, where plastic particles are more likely to remain in the edible parts.

It’s not just the visible bits we’re talking about—many of these particles are microscopic or even nanoplastics, and they may be embedded in the meat of long-lived fish, stored in the gills, or passed along from prey species. Because plastic attracts other toxins, like mercury and persistent organic pollutants, the concern isn’t only the plastic itself and what it carries.

Top predators in the food chain tend to accumulate more microplastics and toxins over time, a process known as bioaccumulation. That means species like tuna, swordfish, and even some salmon may pose higher risks than smaller, short-lived species.

While the science is still evolving, current evidence suggests that frequent, long-term plastic exposure through seafood could contribute to health issues ranging from inflammation to hormone disruption. The routes of exposure aren’t limited to digestion—researchers are also exploring whether microplastics can enter the bloodstream, cross the gut barrier, or affect internal organs after consumption.

We don’t have definitive answers yet, but one thing is clear: plastic emissions are not just an environmental concern—they’re becoming dietary.

What the Science Says—And What We Still Don’t Know

The research on microplastics in fish and what that means for our health is growing fast. However, there are still many unanswered questions for every study that raises a red flag.

We know microplastics are present in marine food webs, including species we regularly eat. We know they can carry chemical additives and pollutants. Humans consume them through fish, shellfish, and other exposure routes. But what are the long-term risks of microplastics in our bodies? That part’s still unfolding.

A significant challenge in tracking microplastics in fish is the lack of a standard testing method. Labs use different approaches, which makes it difficult to compare results or understand where the plastic goes, whether it passes through the body, gets absorbed into tissue, or remains in organs.

Another gap is the role of nanoplastics. These are smaller than microplastics and far more likely to cross biological barriers. But because they’re so difficult to detect, most research still doesn’t account for them, meaning we may underestimate potential impacts.

Scientists are also calling for more clarity around chronic exposure. A single contaminated meal may not cause harm, but what about small doses over a lifetime? Especially when paired with other stressors like mercury, pesticide residues, or endocrine-disrupting chemicals?

Even the researchers publishing these studies are being cautious. They’re not saying we have all the answers yet—but they are calling on governments to cut plastic production and pollution now instead of waiting for more toxicology data to fill in the blanks.

The evidence is growing, but the science is still catching up to the scale of the problem. What we already know is reason enough to take this seriously—and start asking better questions about what we’re putting into the environment and, ultimately, into ourselves.

Can We Still Eat Fish Safely?

The short answer: yes—but with awareness.

Fish and seafood can still be part of a healthy diet, but knowing how microplastics affect them can help you make more informed choices. Not all seafood carries the same level of risk, and how it’s prepared matters, too.

Whole fish and shellfish—like mussels, clams, sardines, or anchovies—are more likely to contain microplastics in the parts we eat. That’s because the digestive tract (where most plastic particles are found) is often consumed along with the meat.

Filleted fish usually have the stomach and intestines removed before they’re sold, which reduces the chances of microplastic exposure. But it’s not guaranteed, especially with long-lived or top predator species like tuna or halibut, where plastic particles may build up in the muscle tissue over time.

If you’re trying to minimize your exposure, here are a few things to consider:

Choose smaller, short-lived fish—they accumulate fewer toxins and plastics.
Vary your protein sources, especially if you eat seafood frequently.
Pay attention to how your seafood is sourced. Some aquaculture operations are taking steps to reduce plastic exposure, while others rely heavily on plastic-based equipment.

Ultimately, the issue isn’t whether seafood is “safe” or “unsafe.” It’s about understanding the bigger picture: the more plastic we put into the environment, the more it finds its way back into the food chain. Being selective with what we eat helps, but reducing plastic pollution at the source protects long-term food safety.

What You Can Do

You can’t remove microplastics from the ocean yourself, but your choices still matter. While scientists and policymakers work on big-picture solutions, there are steps we can take to lower our exposure and reduce the demand for plastic in the first place.

1. Make informed seafood choices

When possible, opt for filleted fish over whole shellfish, especially if you eat seafood often. Smaller, short-lived species generally contain fewer accumulated pollutants than large, predatory ones. Diversifying your protein sources is another way to reduce exposure without giving up seafood entirely.

2. Reduce plastic in your daily life

Every piece of plastic we avoid is one less that could end up in the ocean. Look for plastic-free packaging, reusable containers, and natural materials instead of synthetics—especially for clothing, kitchenware, and personal care.

3. Support systems that make better choices easier

Many of the most impactful solutions are systemic, from reusable packaging startups to refill stations and extended producer responsibility (EPR) laws. Shop from companies that actively reduce plastic emissions and support policies that hold polluters accountable.

4. Wash your clothes more mindfully

Microfibers from synthetic fabrics are a significant source of microplastic pollution. Washing full loads in cold water, using a microfiber-catching laundry bag or filter, and skipping the dryer when possible can all help.

5. Stay informed and speak up

Policy change happens faster when people know the stakes. Follow research updates, share your learning, and encourage your community and local leaders to prioritize plastic reduction.

This Has Been About Microplastics in Fish

Microplastics in fish aren’t just an environmental issue—they’re a food issue, a health issue, and a systems issue. The research is still unfolding, but the message is already clear: plastic is showing up where it doesn’t belong, including in the seafood many of us eat.

While we can’t eliminate microplastics overnight, we can make choices that reduce exposure and push for change. Choosing seafood more carefully, cutting back on single-use plastic, and supporting policies that reduce plastic emissions all move us in the right direction.

Even small shifts—like choosing a plastic free dish soap or using a microfiber filter in your laundry—can move the needle when we’re all pulling in the same direction. It’s not about perfection. It’s about pressure, and enough of it in the right places can lead to real change.

The more we understand how microplastics affect our health and environment, the stronger the case becomes for rethinking how we use plastic—and how we let it shape our future.

References

Perkins, T. (2025, February 3). Study finds microplastic contamination in 99% of seafood samples. The Guardian. https://www.theguardian.com/us-news/2025/feb/03/seafood-microplastic-contamination-study ↩︎
Times of India. (2025, June 5). Study reveals widespread microplastic presence in seafood along Vizag coast. https://timesofindia.indiatimes.com/city/vijayawada/study-reveals-widespread-microplastic-presence-in-seafood-along-vizag-coast/articleshow/121629222.cms ↩︎
Traylor, S. D., Granek, E. F., Duncan, M., & Brander, S. M. (2024). From the ocean to our kitchen table: Anthropogenic particles in the edible tissue of U.S. West Coast seafood species. Frontiers in Toxicology, 6, 1469995. https://doi.org/10.3389/ftox.2024.1469995 ↩︎
Kacapyr, S. (2024, May 22). Study maps human uptake of microplastics across 109 countries. Cornell Chronicle. https://news.cornell.edu/stories/2024/05/study-maps-human-uptake-microplastics-across-109-countries ↩︎