Benthic disturbance due to fish farming analyzed under different levels of taxonomic resolution

The multivariate patterns resulting from analyses of macrobenthic abundance data at different taxonomic levels are compared among different sites subject to a varying degree of disturbance due to sea bream and sea bass farming in 3 Mediterranean coastal areas. The results confirmed that there is little information loss with lower taxonomic resolution but showed no relationship between the level of pollution in an area and the correlations between similarity matrices at the species level and those derived from analysis of higher taxa. A cost/benefit ratio analysis, used for the selection of the optimal taxonomic level for the analysis of macrofaunal data, showed that the family level gives the best balance between precision of the results and decrease in taxonomic effort, therefore indicating that monitoring of fish farming effects could be carried out at the family level.