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At a glance

Eco-rating Mercury Omega-3s
+-Catfish (U.S.)


The wild channel catfish resides in freshwater rivers and streams in North America and feeds on other small fish, insects and mollusks. Catfish sold in markets are usually farm-raised in ponds in the southeastern United States. A wild catfish can grow up to 4.3 feet (1.3 meters) in length and live up to 16 years.

Commercial Sources

Channel catfish are native to the rivers of central North America, from southern Canada to northern Mexico. However, they have been introduced into Europe, South America, Asia and Africa.

The main source of channel catfish is the United States.

Note: Vietnam is another important source of catfish for the United States. However, Vietnamese catfish are a different species.

Capture Methods

Channel catfish come from fish farms where they are raised in ponds.



Basa are a species of freshwater catfish native to the Mekong and Chao Phraya basins of southeast Asia. They are in the family Pangasiidae, or shark catfishes.

Commercial Sources

Basa are raised in Vietnam. The U.S. is importing an increasing amount of basa, as a less expensive alternative to channel catfish.

Capture Methods

Most basa are grown in cages suspended under barges in the Mekong River. Basa are also grown in earthen ponds.



Tra are a species of freshwater catfish native to large rivers in southeast Asia. They are in the family Pangasiidae, or shark catfishes. Tra are omnivorous and can grow to be 4 1/2 feet (1.4 meters) long.

Commercial Sources

The two main producers of tra are Vietnam and Thailand. Tra, formerly marketed as catfish, often goes by the market name basa in the United States.

Capture Methods

Most tra are grown in cages suspended under barges in the Mekong River in Vietnam. Tra are also grown in earthen ponds.

+-Pangasius (Farmed, Vietnam)


<p>Sutchi Catfish, aka Pangasius, raised in pond systems in Vietnam is a “worst” choice due to dumping of sludge from pond systems, contributing to cumulative level effluent impacts, and high use of antibiotics during production.</p>

Recommended servings per month

Contaminant Men Women Kids 6-12 Kids 0-5
Catfish (U.S.) Mercury 4+ 4+ 4+ 4+
Basa Mercury 4+ 4+ 4+ 4+
Tra Mercury 4+ 4+ 4+ 4+
Pangasius (Farmed, Vietnam) Unknown
Eco details: 
  • Native to the Southeast U.S., channel catfish are the most commonly farmed fish in the U.S., accounting for two-thirds of U.S. aquaculture in 2003.
  • They are raised in an eco-friendly way in ponds on converted agricultural land.
  • Basa and Tra, species not closely related to channel catfish, are being imported in increasing quantities from Vietnam, Thailand and China, where there is little government regulation of farming operations.