U.S. Food and Drug Administration (FDA):  

The agency responsible for regulating and monitoring imports of seafood into the United States.

U.S. Department of Commerce - International Trade Administration: 

Import Administration is the U.S. government agency responsible for enforcement of trade laws and agreements.

NOAA Fisheries - National Marine Fisheries Service:  Promotes sustainable fisheries, recovery of protected species, and the health of coastal marine habitats in the USA.  In addition to its many duties relating to domestic fisheries, The National Marine Fisheries Service has a fish inspection division that can be a helpful resource for importers and exporters to the U.S.

Canadian Food Inspection Agency: 

CFIA, the Canadian Food Inspection Agency, is the department responsible for enforcing regulations relating to importation of Seafood into Canada.

U.S. Customs Service Official Web Site: 

The U.S. customs service is responsible for monitoring and enforcing U.S. import regulations relating to Tariffs, Duty , Quotas. If you are an exporter, this site can help with most information you might need relating to the above matters.

National Fisheries Institute (NFI):  

The NFI advocates the interests of the fish and seafood industry in Congress and before regulatory agencies. They also promote and defend the industry and its products to the media and consumers.

International Chamber of Commerce:

Excellent source for regulations governing some aspects of International trade and the use of Letters of Credit.

Uniform Code Council, Inc.:

Do you need to know more about UPC codes , Bar Coding, etc.? This is the place to start!

Generic HACCP Plans: 

HACCP, Hazard Analysis Critical Control Point plans are required for seafood imports by the U.S. Government.
If you are exporting seafood to the U.S. you need a HACCP Plan. This site will help you get started.

UNZ & Co. - Compliance Experts Since 1879:

Pro-Forma Invoices, Shippers Declarations and other forms related to International Trade are published by this company.