Does Salmon Have High Microplastics? Investigating the Contamination

December 21, 2025 •

8 min read

Microplastics have been found in 99% of seafood samples tested in a recent Portland State University study. This alarming statistic has prompted many to question: does salmon have high microplastics, and if so, what are the implications for our health and the environment?

Quick Summary

Studies have consistently detected microplastics in salmon, but concentrations can vary. Factors like farmed versus wild sources and seafood type influence contamination levels. The research is ongoing, but consumers can take steps to mitigate their exposure.

Key Points

Microplastics are widespread: Microplastics have been found in both wild-caught and farmed salmon due to pervasive environmental contamination.
Levels vary by source: While some studies indicate higher microplastic levels in farmed salmon due to concentrated environments and feed, others find wild fish can have more overall contaminants, making the comparison nuanced.
Other seafood may have higher levels: Filter-feeders like mussels and shrimp often contain significantly higher concentrations of microplastics than salmon because their feeding methods directly ingest large quantities of particles.
Health risks are still being studied: The long-term effects of microplastic ingestion on human health are not yet fully understood, though potential risks from associated chemicals exist.
Practical steps can reduce exposure: Consumers can minimize intake by choosing sustainable sources, diversifying their protein, and limiting consumption of seafood where the entire organism is eaten.
Systemic change is needed: Individual actions help, but ultimately, addressing the problem requires broader policy changes to reduce plastic production and pollution at its source.

Understanding Microplastic Contamination in Salmon

Microplastics are tiny pieces of plastic, less than five millimeters in size, that result from the breakdown of larger plastic products. They are now ubiquitous in marine ecosystems, making their way into the food web and ultimately onto our plates. Research has confirmed that salmon, both wild-caught and farmed, are not immune to this contamination. Multiple studies in recent years have detected these pervasive particles within their tissues.

The most common microplastic found in fish is synthetic microfibers, shed from our clothing during laundering and entering waterways. Salmon can ingest these particles by mistaking them for food, and the microplastics can then move from the digestive tract into muscle tissue. The level of contamination can differ based on several key factors, which we will explore in detail.

Wild-Caught vs. Farmed Salmon: A Comparison

While both wild and farmed salmon contain microplastics, some evidence suggests varying levels of contamination. The source of the fish is a significant factor in its potential microplastic load.

Wild-Caught Salmon: These fish are exposed to the wide expanse of the ocean, where plastic pollution is a pervasive issue. They ingest microplastics from the water column or through the prey they consume. However, the specific location and migratory patterns can influence their exposure. For example, some studies have shown wild fish to have more overall contaminants than farmed fish, likely due to a different diet, but results can be variable depending on the study.
Farmed Salmon: Farmed salmon are raised in controlled environments like sea pens, where they are exposed to microplastics from the surrounding water, the feed they are given, and the gear used in aquaculture. Some research has indicated higher rates of microplastics in farmed fish compared to their wild counterparts, potentially due to these concentrated exposure points. Conversely, a 2019 Mowi study found no microplastics in its farmed salmon fillets, though it's important to note the industry origin of this study.

Comparing Microplastics in Salmon with Other Seafood

It's important to put the microplastic content of salmon into a broader context. Not all seafood accumulates microplastics equally. Shellfish, for instance, often exhibit higher contamination levels due to their feeding habits.

Filter-Feeders: Bivalves like mussels, oysters, and clams are filter-feeders, meaning they process large volumes of water and inadvertently filter out and accumulate high concentrations of microplastics. Since their entire bodies are consumed, including the digestive tract, humans ingest these particles directly.
Shrimp: Pink shrimp have also shown exceptionally high concentrations of microplastic particles, often mistaking them for food. This is another example of a species that can have a higher microplastic load than salmon.
Predatory Fish: Larger carnivorous fish higher up the food chain, such as tuna, may accumulate more microplastics and toxins through bioaccumulation. However, specific contamination levels vary by species and location.

The Health Implications of Ingesting Microplastics

The potential health risks of consuming microplastics via seafood are a growing area of scientific research. While much remains unknown, some potential concerns have been identified. Microplastics can carry harmful chemicals and additives used in their manufacturing process, such as PFAS and phthalates. These particles can also adsorb other pollutants from the surrounding water. When ingested, these substances could potentially interfere with hormones or accumulate over time.

However, some toxicologists believe the evidence indicates microplastic particles readily pass through the digestive tract and exit the body, and that seafood is a relatively small source of microplastic exposure compared to other sources like indoor air and bottled water. The scientific consensus is still developing, and more research is needed to fully understand the long-term effects on human health.

Table: Microplastics in Seafood (Comparative Concentrations)


Seafood Type	Typical Feeding Behavior	Potential for High Microplastic Concentration	Explanation
Farmed Salmon	Captive, fed commercial feed	Higher rates observed in some studies	Exposure from farm environment and contaminated feed.
Wild Salmon	Migratory, varied diet	Variable, but lower than filter-feeders	Wide-ranging exposure, but not a filter-feeder.
Mussels & Oysters	Filter-feeder (eats whole body)	Very High	Filter large volumes of water, consuming microplastics.
Shrimp	Bottom or surface feeder	High	Mistake microplastics for food; digestive tract often eaten.
Tuna	Predator, high trophic level	Moderate to High	Bioaccumulation from consuming smaller, contaminated fish.
Cod & Halibut	Bottom feeder	Moderate	Ingest microplastics from sediment.

Reducing Your Microplastic Exposure from Seafood

While avoiding microplastics entirely is impossible, consumers can take several proactive steps to minimize their exposure from seafood.

Best Practices for Consumers

Choose seafood carefully: Opt for species that are less likely to accumulate high levels of microplastics, such as larger fish where the gut is removed before eating. Whole fish, where the fillets are primarily what's consumed, often contain fewer microplastics in the edible portion compared to smaller seafood eaten entirely, such as mussels or shrimp.
Source sustainably: Supporting sustainable fishing and aquaculture practices can help address the root cause of ocean pollution. Some guides, like Seafood Watch, can assist in making informed choices.
Rinse seafood thoroughly: Since some surface-level contamination can occur during processing and packaging, rinsing fillets and whole fish before cooking may help.
Diversify your protein intake: Incorporating a variety of protein sources, including plant-based options, can reduce reliance on any single source of food.
Consider the source: Research suggests that wild-caught may have less microplastic than farmed, although this can be variable. Buying directly from trusted, local fisheries may reduce the risk of microplastic exposure related to industrial-scale processing.

Conclusion

In short, yes, salmon does have microplastics, as do most other types of seafood and food products. The concentration, however, is not as high as in filter-feeding shellfish or shrimp, and it can vary between wild and farmed fish. While the long-term human health impacts are still being investigated, experts agree that the best strategy is to reduce overall plastic exposure by making conscious choices. Consumers can help by choosing sustainable sourcing, diversifying protein intake, and supporting broader policy changes to address plastic pollution at its source. Despite the presence of microplastics, the nutritional benefits of seafood remain significant, and alarms should not deter people from eating a balanced diet.

How Microplastics Get into Salmon

Ingestion: Salmon consume microplastics directly from the water column or through their prey, which has also ingested plastic.
Feed Contamination: Farmed salmon may ingest microplastics from their feed, which can be contaminated with plastic particles.
Water Contamination: The water in which salmon live, whether wild or farmed, is contaminated with microplastics from various sources.
Processing Contamination: Post-harvest processing can also introduce microplastics from plastic containers, tools, and even airborne particles.
Bioaccumulation: Microplastics can move up the food chain, with larger predators like salmon accumulating particles from the organisms they consume.

What are Microplastics and Where Do They Come From?

Microbeads: Tiny plastic beads found in some personal care products, which are now being phased out but are a historical source.
Fibers: Synthetic fibers from clothing like polyester and nylon shed during washing and are a major source of microplastic pollution.
Fragments: The breakdown of larger plastic items like bottles, packaging, and fishing gear into smaller pieces.
Tire Dust: A less-known but significant source of microplastic pollution.
Pellets: Pre-production plastic pellets, known as nurdles, are often lost during transport and end up in the environment.

What Can We Do to Address the Problem?

Policy and Regulation: Support policies that regulate plastic production and waste management, such as single-use plastic bans.
Consumer Choices: Reduce personal plastic footprint by choosing sustainable options and avoiding excessive plastic packaging.
Support Research: Encourage further research to understand the full extent of microplastic contamination and health impacts.
Improve Waste Management: Advocate for better waste management systems and ocean cleanup efforts.
Filter Water and Air: Use water filters that can remove microplastics and consider indoor air filtration to reduce airborne particle intake.

The Evolving Science of Microplastics

Detection Methods: Scientists are developing new techniques to detect and quantify microplastics in seafood, including the use of nuclear technology.
Data Standardization: There is a push to standardize data collection methods to get a clearer picture of contamination levels and sources.
Toxicity Research: Ongoing research is exploring the toxicity of microplastics and their associated chemicals on both marine life and humans.

Seafood Recommendations

Prioritize Wild: Some studies suggest wild-caught salmon might have a lower microplastic load than farmed, but this can vary.
Eat Larger Fish: Consuming the fillets of larger fish, where the digestive tract is removed, can be a way to reduce microplastic intake compared to eating smaller seafood whole.
Choose Carefully: Be mindful of filter-feeding shellfish like mussels and clams, as they tend to accumulate higher levels of microplastics.
Diversify: A balanced diet with various protein sources is a good approach to minimize reliance on any single type of seafood.

Conclusion on the Microplastic Issue

Ubiquitous Problem: Microplastics are present in virtually all seafood, including salmon, due to widespread environmental contamination.
Variable Levels: The level of microplastic contamination varies significantly depending on the species, feeding habits, and whether the fish is wild-caught or farmed.
Health Concerns: While the long-term health effects are still under investigation, potential risks from both the plastic particles and associated chemicals exist.
Actionable Steps: Consumers can make informed choices about the seafood they eat, support sustainable practices, and reduce their overall plastic footprint.

Final Recommendations

Educate Yourself: Stay informed about the latest research on microplastics in seafood and other food sources.
Reduce Plastic Use: Minimize single-use plastics and support companies with eco-friendly packaging.
Advocate for Change: Support policies aimed at reducing plastic pollution at its source.

Final Thought

While the presence of microplastics in salmon is a real concern, the issue is part of a larger, systemic plastic pollution problem. Making informed choices and advocating for systemic change is the most effective approach.

Does Salmon Have High Microplastics? A Closer Look

Comparison to Shellfish: Salmon generally contains lower levels of microplastics in its edible flesh compared to filter-feeding shellfish like mussels and oysters.
Farmed vs. Wild Debate: While some studies show higher microplastics in farmed fish, other research presents a more nuanced picture, and industry-funded studies have found otherwise.
Edible Portions: The contamination often resides more in the gills and digestive tract of fish. Since fillets are commonly consumed, the direct intake may be lower than for seafood eaten whole.
Overall Context: It's important to remember that microplastics are in a wide range of foods and in our air, not just seafood.
Research Limitations: Standardized methods for testing and a full understanding of health impacts are still developing, making definitive comparisons challenging.

Conclusion on Salmon and Microplastics

In summary, salmon, like all seafood, contains microplastics, but its levels are generally lower than species like mussels or shrimp. Choosing wild-caught may offer some advantage, but both wild and farmed salmon are exposed to plastic pollution. The health risks associated with this intake are still under investigation, but prudent consumption and broader plastic reduction efforts are the best strategy.

Key Factors Influencing Microplastic Contamination

Feeding Habits: A species' feeding behavior significantly impacts its microplastic load. Filter-feeders and bottom-dwellers tend to have higher concentrations.
Habitat: The pollution levels in the water where the fish live are a primary determinant of contamination.
Processing: How the seafood is handled, processed, and packaged can introduce additional microplastics.
Size: Smaller fish that eat micro-organisms directly can be highly contaminated, while larger fish might accumulate plastics via the food chain.

Tips for Safer Seafood Consumption

Choose Local: When possible, buy seafood from local, reputable sources with sustainable practices.
Diversify: Mix up your protein sources to avoid excessive exposure from a single type of seafood.
Limit Shellfish: While nutritious, be mindful of intake, especially of filter-feeders eaten whole.
Support Regulation: Advocate for policies that address the root cause of plastic pollution in our oceans.

Final Word on Microplastics in Salmon

While microplastics are present in salmon, the concentrations may not be as high as in some other seafood. A balanced diet and supporting efforts to reduce plastic pollution are the most effective ways to manage this issue.

Frequently Asked Questions

There is conflicting information, but some studies have indicated that farmed salmon can have higher microplastic levels due to exposure in concentrated environments and contaminated feed. However, a 2019 Mowi study found no microplastics in their farmed salmon fillets, though this was from the industry itself.

Microplastics are most commonly found in the gills and digestive tract of fish. Since humans primarily consume the edible fillet, the direct intake may be lower than for species where the entire organism is eaten.

The long-term effects of ingesting microplastics on human health are still being investigated. While there are concerns about associated chemicals and potential accumulation, more research is needed to determine the full impact.

Salmon generally contains lower levels of microplastics in its edible flesh compared to filter-feeding shellfish like mussels and oysters, which process large volumes of water. Shrimp also have been found with high concentrations.

You can reduce exposure by diversifying your protein sources, opting for larger fish where the gut is removed, rinsing seafood thoroughly, and supporting sustainable fishing practices.

Yes, experts often emphasize the significant nutritional benefits of seafood, such as omega-3 fatty acids. Some toxicologists suggest that compared to other environmental sources, seafood contributes a relatively small amount of microplastics. The health benefits are widely considered to outweigh the currently understood risks, especially with careful sourcing.

Synthetic microfibers shed from synthetic fabrics during washing are a major source of microplastic contamination in salmon. These fibers enter waterways and are ingested by marine life.