Multivariate analyses of the role of environmental factors in seasonal and site-related growth variation in the Pacific oyster Crassostrea gigas

Abstract

Monthly increases in shell height were measured for 2 age classes (Years 0 and 1) of a common broodstock of oysters Crassostrea gigas in 10 locations in British Columbia, Canada, over 14 mo. Measurements were also taken of several environmental variables known to affect oyster growth. Based on comparisons of shell height growth curves, sites were grouped into low, medium and high growth categories which were similar for both age classes of oysters. According to discriminant function analysis, differences in salinity and particulate organic matter (POM) concentration distinguished low growth sites from medium and high growth areas. Medium and high growth areas were segregated solely on the basis of food-related variables: POM, carotenoid concentration and Secchi depth.