; or (B) navigable waters (as defined in section 502 of the Federal Water Pollution Control Act ( 33 U.S.C. 1362 )); and (3) if the fish is caught, taken, or harvested by a vessel, that vessel is a vessel of the United States (as defined in section 3 of the Magnuson-Stevens Fisheries Conservation and Management Act ( 16 U.S.C. 1802 )). (b) Method of notification (1) In general The information described in subsection (a) may be provided to consumers by means of a label, stamp, mark, placard, or other clear and visible sign on the fish, or on the package, display, holding unit, or bin containing the fish, at the final point of sale to consumers. (2) Labeled commodities If fish is already individually labeled for retail sale with the label described in subsection (a), the retailer shall not be required to provide any additional information to comply with this section. 298C. Enforcement (a) Warnings If the Secretary determines that a retailer of fish or person engaged in the business of supplying fish to a retailer is in violation of section 298B, the Secretary shall— (1) notify the retailer or person of the determination of the Secretary; and (2) provide the retailer or person a 30-day period, beginning on the date on which the retailer or person receives the notice under paragraph (1) from the Secretary, during which the retailer or person may take necessary steps to comply with section 298B. (b) Fines (1) In general The Secretary may fine a retailer or person under paragraph (2) if, on completion of the 30-day period described in subsection (a)(2), the Secretary determines that the retailer or person— (A) has not made a good faith effort to comply with section 298B; and (B) continues to willfully violate section 298B with respect to the violation regarding which the retailer or person received a notification under subsection (a)(1). (2) Notice and hearing