A spokeswoman for the Southern Shrimp Alliance, Deborah Regan said: "The US shrimp industry is in dire straits due to unfair imports."

The petitions seek to restore fair trade by imposing anti-dumping tariffs against countries that sell shrimp at "dramatically lower prices than they sell in their home countries and third countries," Regan charged.

Potential duties range from 30% to more than 200%, she said.

The six petitions were being delivered to the Commerce Department and International Trade Commission on Wednesday, she added.

Low prices

Regan said overproduction around the world meant larger amounts entering US at lower prices, and low dockside shrimp prices meant closing businesses and rising unemployment in the United States.

Yet, quoting a Wall Street Journal report, she said "Consumers are not benefiting from low dockside prices."

Some producers have argued their farming methods cut costs to make them more competitive than trawling, the main US production method.

But "I think it's legally irrelevant whether farming is more efficient," Regan said.

"Fishermen today should understand that we have taken legal action, the only thing that we can do to offset unfair trade...  and what the industry has said it needs to remain viable."