All boats used for harvesting or transporting shellfish, including “buy” boats, and all trucks used for hauling bulk, bagged, containerized, or otherwise packaged shellstock shall be constructed, operated, and maintained so as to prevent contamination, deterioration, or decomposition of the shellfish, and shall be kept clean. Adequately refrigerated trucks shall be used to transport shellstock when the ambient air temperature is such that unacceptable levels of bacterial growth may occur in the shellstock species to be transported.