 Productivity of the Pacific oyster can be described as the amount of meat produced in relation to the amount of seed planted on cultch.The productivity of a farm also depends on the interaction of biotic factors, such as mortality, growth, and oyster size, as well as the quality of the seed and the growing technique used (off bottom, bottom, suspended or floating culture).The main causes of mortality in the Pacific oysters are natural mortality (age), predators, disease, environmental conditions (ice, freak winds), competition for space (crowding of cultch), silting (sediment runoff from land), and cluster separation (process of breaking up clusters of oysters into as many individual oysters as possible).