APPRAISAL OF WATERSHED PARAMETERS INFLUENCING THE MACROBENTHOS USING MULTIVARIATE STATISTICAL ANALYSIS, PRINCIPAL COMPONENT ANALYSIS

The present study employed multivariate statistical technique, Principal Component Analysis, to evaluate the physicochemical parameters affecting the density and distribution of two clam species in the estuary. Twelve physicochemical parameters were measured at Kayamkulam estuary for two years. Variations from 72.689% to 85.411% were observed during the study period. Factor loadings of more than 0.60 on significant variables were only considered for interpretation. The factor loadings on various factors affirmed that salinity, sediment texture and pH are major guiding factors that exert influence on the density of clams. From PCA four components were pooled out as principal factors in the estuary viz., sand, temperature, organic carbon, and salinity. PCA results expounded the environmental factors impacting the density and distribution of macrobenthos in the estuary.