Annual Biodeposition and Gross Energy Budget of Mature Pacific Oysters, Crassostrea gigas

• Published in: Journal of the Fisheries Research Board of Canada
• Main Author: Bernard, F. R.
• Format: Article in Journal/Newspaper
• Language: French
• Published: Canadian Science Publishing 1974
• Subjects: General Medicine; Pacific; Crassostrea gigas
• Online Access: http://dx.doi.org/10.1139/f74-030; http://www.nrcresearchpress.com/doi/pdf/10.1139/f74-030

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/m 2 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/m 2 and furnish an important nutritional substrate. Another important contribution to the food web is the annual release of gametes, equivalent to 502 kcal/m 2 reef.