Spatial Heterogeneity of Phytoplankton in a Near-Shore Environment

An analysis of variance model for phytoplankton distribution is described, which allows the partition of the variance of chlorophyll observations into effects due to differences between stations, to differences between replicate samples at the same station, and to handling and analytical error. When the model was applied to observations of chlorophyll made in St. Margaret's Bay, N.S., it was found that, on the average, the variance between replicate samples on the same station was of the same magnitude as the analytical error variance. Significant differences were revealed between stations even at densities as high as 10 stations per 0.0625 sq miles. As the sampling area was increased (but the number of stations kept constant), the between-station variance rose rapidly, to a density of 10 stations per sq mile, after which it remained relatively constant. The maximum value of the between-station component of the variance was about 10 times the average for the between-replicate component. Heterogeneity of p...