Which fish are low in mercury in Nigeria? A Safe Seafood Guide

January 9, 2026 •

3 min read

According to a 2017 medical advisory reported by The Guardian, a Nigerian doctor highlighted the neurological damage risk from high-mercury fish consumption. This guide helps you identify which fish are low in mercury in Nigeria, allowing you to enjoy the nutritional benefits of seafood without the risk.

Quick Summary

This article details safe, low-mercury fish options available in Nigeria, explaining why certain species accumulate less mercury. It provides crucial information for making informed seafood choices, especially for pregnant women, nursing mothers, and children.

Key Points

Choose smaller fish: Smaller, shorter-lived fish like sardines and tilapia accumulate less mercury than larger, older predators.
Favour Tilapia and Catfish: Popular Nigerian staples like tilapia and catfish are considered safe, low-mercury choices.
Prioritise Sardines: Canned sardines (Titus) and fresh sardines are excellent low-mercury options rich in Omega-3s.
Limit Large Predators: Avoid high-mercury fish such as shark, king mackerel, and swordfish, which accumulate toxins higher up the food chain.
Protect Vulnerable Groups: Pregnant women, breastfeeding mothers, and young children should strictly stick to low-mercury fish options for brain and nervous system safety.
Source Smart: Be mindful of the fish's origin, as local water pollution can affect mercury levels. Patronise reputable seafood vendors.

Understanding Mercury in Fish

Mercury is a naturally occurring element that enters water bodies through various sources. Microorganisms convert it into methylmercury, a toxic form that accumulates in the food chain. Larger, predatory fish accumulate higher concentrations by consuming smaller, contaminated fish.

While most adults can consume small amounts of high-mercury fish, vulnerable populations like pregnant women, nursing mothers, and young children face serious health risks from high mercury exposure, which can affect the developing brain and nervous system. Choosing low-mercury fish is therefore vital in Nigeria.

Low-Mercury Fish in Nigeria: Safe Choices for Your Plate

Many delicious and nutritious low-mercury fish are commonly found in Nigerian markets. These are typically smaller and lower on the food chain, accumulating fewer toxins.

Popular Low-Mercury Fish Options

Tilapia: A popular and widely farmed fish in Nigeria, known for its low mercury content.
Sardines (Titus): Fresh and canned sardines are low in mercury and rich in omega-3 fatty acids.
Catfish: Generally a low-mercury option in Nigerian cuisine, especially from freshwater sources.
Croaker: Atlantic Croaker is a low-mercury 'Best Choice', and a Nigerian study found 'croaker fish' to be relatively safe.
Shrimps and Prawns: These shellfish are low on the food chain and typically have very low mercury levels.
Atlantic Mackerel: The smaller Atlantic Mackerel is a safe, low-mercury option, unlike the larger King Mackerel.

High-Mercury Fish: Species to Limit or Avoid

Limit or avoid fish known for high mercury content, which are often large, long-lived predators.

Shark: Avoid due to very high mercury levels.
King Mackerel: This large species has significantly higher mercury than Atlantic Mackerel.
Swordfish and Marlin: Both are large predators with high mercury.
Tuna (Fresh/Large): Large, fresh tuna steaks, especially Bigeye, have higher mercury than canned light tuna. Limit canned albacore ('white') tuna.

Low vs. High Mercury Fish Comparison Table


Feature	Low-Mercury Fish	High-Mercury Fish
Examples	Tilapia, Sardines, Catfish, Shrimps, Atlantic Mackerel	Shark, King Mackerel, Swordfish, Bigeye Tuna
Trophic Level	Lower on the food chain	Higher on the food chain (apex predators)
Typical Size	Smaller	Larger
Life Span	Shorter	Longer
Consumption Frequency	Safe for regular, moderate consumption	Should be limited or avoided, especially for vulnerable groups
Best For Vulnerable Groups	Yes (pregnant women, children)	No
Local Availability	Common and readily available in Nigerian markets	Less common, but still found in some seafood markets

Special Considerations for Vulnerable Groups

Pregnant women, breastfeeding mothers, and young children are most at risk from mercury exposure. They should consistently eat low-mercury fish and completely avoid high-mercury species. Omega-3s in fish are crucial for development. Serve smaller, thoroughly cooked portions to children.

The Role of Location and Sourcing in Nigeria

Local environmental factors and industrial activities can influence mercury levels in specific waterways in Nigeria. Fish from industrial areas like Lagos Lagoon may have higher heavy metal concentrations. Inquire about the source and patronise reputable vendors.

Conclusion

Making informed seafood choices is vital for enjoying health benefits without mercury risk. In Nigeria, choosing low-mercury fish like tilapia, sardines, catfish, and Atlantic mackerel is safe and boosts protein and omega-3 intake. Avoiding large predators like shark and king mackerel safeguards health, particularly for vulnerable family members. Follow these guidelines to enjoy Nigerian fish dishes with peace of mind.

For more detailed nutritional information and safety guidelines, consult authoritative sources like the {Link: U.S. Food and Drug Administration https://www.fda.gov/food/consumers/advice-about-eating-fish}.

Additional Considerations for Safe Fish Consumption

Low-mercury fish offer nutritional benefits like protein and omega-3 fatty acids. Both fresh and canned sardines and light tuna are good low-mercury options. When buying fresh fish, look for clear eyes, bright red gills, and firm flesh. Fish size, age, position on the food chain, and environmental pollution all influence mercury levels. Making smart choices about the type and source of fish ensures safe consumption, especially for vulnerable groups.

Frequently Asked Questions

In Nigeria, popular low-mercury fish options include tilapia, catfish, sardines (titus), and smaller species like Atlantic mackerel and croaker.

Yes, it is safe and recommended for pregnant women to eat low-mercury fish in moderation. The omega-3s are beneficial for fetal brain development. However, they should avoid high-mercury species like shark and king mackerel.

No, cooking methods like frying, grilling, or poaching do not remove mercury from fish. Mercury is bound to the protein in the fish's muscle tissue.

Sardines typically have very low mercury levels because they are small, plankton-eating fish. While smaller Atlantic mackerel are also low, larger species like king mackerel have very high levels.

Farmed fish, such as most tilapia, are often lower in mercury than wild fish because their environment can be more controlled, reducing their exposure to pollutants. However, locally farmed catfish should be sourced carefully, as some local studies suggest potential contamination risks.

Look for clear, bright eyes, firm and shiny skin, and bright red gills. The flesh should be elastic when touched, and the fish should have a mild, clean smell. Cloudy eyes, dull skin, or a strong odor are signs of an old fish.

Yes, children can eat low-mercury fish as part of a healthy diet. Examples include salmon, tilapia, and canned light tuna. It is advisable to avoid high-mercury types and adhere to smaller serving sizes.