Objective Selection of Sensitive Species Indicative of Pollution-Induced Change in Benthic Communities. I. Comparative Methodology

Abstract

Isolation of groups of species indicative of pollution-induced effects on benthic communities has traditionally been based on subjective ecological expertise. A review of more general methods covering the use of diversity indices, computer based multivariate analyses is glven. The conclusion drawn is that there are many drawbacks with these methods too and their so-called 'objectivity' is questioned. Using a modification of the log-normal distribution of individuals among species a new method is proposed which can be used to isolate objectively groups of species sensitive to pollution effects. An example is drawn from a time-series study on effects of organic enrichment on a soft-sediment community. The method suggested has a sound theoretical base, is simple to plot, utilizes all the data on individuals and species in a community and identifies groups of species that can be used in reduced scale monitoring programmes.