The distinction is habitat-based: ocean perch refers to marine species (primarily Sebastes spp., including Acadian redfish and Pacific rockfish), while freshwater perch lines cover species from inland waters. Supporting documentation such as catch area certificates or species identification records helps establish the correct classification and avoids confusion between the two product types.

Yes. The NESOI designation means this line captures ocean perch not covered by a more specific HTS provision. Importers should confirm that the particular Sebastes or related species being imported does not have an enumerated line in the schedule before defaulting to this residual code. A licensed customs broker can assist with the species-level classification review.