Spatial distribution of Champsocephalus gunnari in Subarea 48.3. Some implications for parameter estimation

Results of the analysis of three consecutive cruises to subarea 48.3 are analyzed. A significant variance component associated with the formation of clusters of stations was found as well as a general trend for increasing densities since 1994. The significant variance component obtained for clusters formed with stations at 8.0 nautical miles implies that considering all stations as independent (as in the estimation of the variance of the mean density) might result in a gross underestimation of the variance. The spatial pattern of density across years might be applied to construct a model of density variability to minimize the variance of estimates of regional parameters.