Final answer:
There was a mix-up in the provided information. Shellstock tags should remain on shellfish containers until they are empty to ensure health and safety traceability. This is unrelated to the ballast water practices of container ships.
Step-by-step explanation:
The question appears to be about regulations related to shellfish and the tags that accompany them during transport and storage. However, the information provided mainly concerns container ships and ballast water management. As such, it seems there was a mix-up in the details provided, as they do not correspond to the question about shellstock tags. Shellstock tags are typically used to identify and provide traceability for shellfish, ensuring their source and harvest dates are recorded for health and safety reasons. These tags are meant to remain attached to the container of shellfish until the container has been emptied, or the contents are used up, to ensure that this critical information is available throughout the shellfish's journey from water to plate.
It's important to note that the practice of ballast water management mentioned in the information pertains to the shipping industry and is used to maintain the stability of ships and prevent the spread of invasive species, which is a separate issue from food safety and shellstock tagging.