The mean annual volume of seawater pumped by Pacific oysters in Departure Bay, British Columbia is 1488 liters/g per year. The energy requirement for metabolism and pumping is 1.74 cal/liter, while the mean annual caloric content of the seawater is 60.4 cals/liter. Annual biodeposition is 8.9 g/g per year; these data applied to a mean biomass of 190 g/m2 for a mature oyster reef show that 22,052 kcal are theoretically available for ingestion, but only 11% are retained, mostly to be biodeposited. The biodeposits have a caloric value of 1545 kcal/m2 and furnish an important nutritional substrate. Another important contribution to the food web is the annual release of gametes, equivalent to 502 kcal/m2 reef.
Spatial variation of trace metals within intertidal beds of native mussels (Mytilus edulis) and non-native Pacific oysters (Crassostrea gigas): implications for the food web?
