Shellfish harvested from moderately contaminated areas normally purge themselves of bacterial contaminants within forty-eight hours, but may be held for up to 72 hrs. Philosophic and practical conflicts surround depuration activities. It also represents a way of assuring consumers of a clean and safe product. Massachusetts has practiced depuration techniques for over sixty years. Depuration has been resisted on several fronts.
Commercial fishermen fear a loss of economic control over the product.
Scientists have retained certain reservations about the process. It has also been found that some shellfish, particularly if damaged during harvest, may not siphon during the depuration period at all. Finally, even if the shellfish can be purged of most of the bacteria contained in their gut, they may not be able to release viruses in their tissues. Others argue that depuration discourages solving the pollution problems which lead to shellfish bed closures. However, given that population models project that by the year 2000 half of the nation's population will be living within the coastal zone, the challenges toward coastal pollution abatement will continue to grow irrespective of practices such as depuration.