Statistical verification of the Chesapeake Bay benthic index of biotic integrity

摘要: The benthic index of biotic integrity (B-IBI) developed for the Chesapeake Bay was statistically verified using simulations and a suite multivariate statistical techniques. B-IBI uses simple scoring system community metrics to assess health infer environmental quality habitats in Bay. Overall, as being sensitive, stable, robust sound. Classification effectiveness increased with salinity, from marginal performance tidal freshwater ecosystems excellent results polyhaline areas. greater classification uncertainty low salinity may be due difficulties reliably identifying naturally unstressed areas or regional ecotones created by stress gradients. Pollution-indicative species abundance, pollution-sensitive diversity (Shannon's index) were most important discriminating between degraded non-degraded conditions majority habitats. Single often performed well multi-metric correctly classifying relative sites. However, redundancy provided stable 'weight evidence' which confidence general conclusions. Confidence limits scores used distinguish among that degraded, non-degraded, intermediate quality, indeterminate condition.