The Use of Multivariate and Graphical Methods in Assessing Environmental Disturbance: Temperate versus Tropical Regions

Abstract

This study is aimed to assess the effectiveness of multivariate analyses and distributional/graphical techniques in assessing the response of macrobenthic assemblages to environmental disturbance caused by fish farming, comparing temperate and tropical regions. The biotic datas were used from samples taken under southern bluefin tuna farms in southern Spencer Gulf, South Australia, and under fish impoundment at coastal region of Demak District, Central Java, Indonesia. Principal Component Analysis (PCA) and Non Metric Multi-Dimensional Scaling (NMDS) were used for analysis the abiotic and biotic datas, respectively. Abundance-Biomass Comparison (ABC) curves were employed to detect the level of disturbance. The results showed that the use of multivariate analyses and distributional/graphical techniques are effective to assess the severity of disturbance, owing to sensitive response of macrobenthic assemblages to environmental disturbance that made it possible to detect the effects of farming activities. The ordination of the MDS and ABC curves showed consistently with Wstatistic and H’ index values in assessing the status of the area in both tropical and temperate regions. They clearly separated the disturbed and undisturbed areas, whether in spatial and temporal, thus the methods may be applied for the datas taken from temperate and tropical regions.