50 CFR §635.41

1. (a)[Reserved]
2. (b)All shipments of tuna or tuna-like species, or their products, in any form, harvested in the ICCAT convention area by a fishing vessel that is required to be listed, but not listed on the ICCAT record of authorized vessels will be denied entry into the United States.
3. (c)All shipments of tuna or tuna-like species, or their products, in any form, harvested in the ICCAT convention area by a fishing vessel listed on the ICCAT record as engaged in illegal, unreported, and unregulated fishing will be denied entry into the United States.
4. (d)All shipments of tuna or tuna-like species, placed in cages for farming and/or transshipment, harvested in the ICCAT convention area and caught by a fishing vessel included on the ICCAT list as engaged in illegal, unreported, and unregulated fishing will be denied entry into the United States.
5. (e)For the purposes of this section, it is a rebuttable presumption that any shipment containing swordfish, bluefin tuna, bigeye tuna, or their products offered for entry into the United States has been harvested by a vessel or vessels of the exporting nation.