Exploring the marine biotic index (AMBI): variations on a theme by Angel Borja.
The results of manipulating the input data to AMBI are explored using various transformations of numerical species abundance (NAMBI), biomass (BAMBI) and production (PAMBI) from a variety of stations on the NE Atlantic shelf at which the pollution/disturbance status is known. There is a close agreement between the proportions of species in the five AMBI ecological groups and a phylum level meta-analysis axis of increasing environmental impact. All AMBI measures provide a better monotonic relationship with the impact axis than do traditional species diversity measures, which show higher diversity at intermediate levels of disturbance. A marginally better relationship with the impact axis of the meta-analysis is achieved by a moderate (square root) transformation of the data. 'Production' data (an appropriate combination of abundance and biomass information) provide only a marginal improvement on abundance data, but are ecologically and functionally much more relevant. Severe transformation of the data, culminating in presence/absence, degrades the relationship with the impact axis, but if only simple species lists are available then these may still be useable in making an environmental assessment.
Warwick
Richard M
RM
Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK. rmw@pml.ac.uk
Clarke
K Robert
KR
Somerfield
Paul J
PJ
D001267:Atlantic Ocean; D018533:Biomass; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D008954:Models, Biological; D015999:Multivariate Analysis; D012722:Sewage; D014873:Water Pollutants
D012722:Sewage; D014873:Water Pollutants