Evaluation of the applicability of a marine biotic index to characterize the status of estuarine ecosystems: the case of Mondego estuary (Portugal)

The need for new tools to assess the environmental status of coastal and estuarine systems encouraged Borja et al. [Mar. Pollut. Bull. 40 (2000) 1100] to develop a new index, the AZTI’s Marine Biotic Index (AMBI), which needs to be tested as much as possible in different geographical areas to assess its applicability. This index was applied in the Mondego estuary (western coast of Portugal) together with the Shannon–Wiener, Margalef, Simpson, and W-statistic indices, which are widely used in detecting the effects of marine pollution. Results show that, in some cases, the AMBI provides a more accurate assessment of environmental conditions than the other indices, which were influenced by the dominance of certain species, allowing us to consider it as a promising tool to characterize marine and estuarine environmental quality.