Butter clams are marine bivalves, Saxidomus giganteus, found in middle to lower intertidal sediments along the Atlantic and Pacific coasts of North America. Smaller specimens are often eaten raw, while larger adults are usually steamed or fried, and they are highly prized for the production of clam chowders. As filter feeders they can accumulate algal biotoxins and contaminants from their environment, so they must be harvested from waters monitored under shellfish sanitation programmes and handled with rapid chilling to keep them safe and of good quality.