Using benthic recruitment to assess the significance of contaminated sediments: the influence of taxonomic resolution

The use of small-scale experimental units as a means of evaluating the ecol ogical effects of contaminated sediments was examined at the species, famil y, mixed and phylum levels of taxonomic resolution. Sediments were taken fr om various locations representing a range of contaminant loads. Containers with these sediments were placed in situ at a relatively uncontaminated loc ation for 90 days. The containers were retrieved and the abundance of the m acrofauna which recruited to the containers was estimated. The results show ed that the composition of the benthic communities in the more highly conta minated sediments differed significantly from those in less contaminated se diments. Analyses at the different taxonomic levels showed that all but the phylum level data showed some differences in community structure among sed iment types. The study showed that small-scale experiments are useful for e xamining the effects of contaminants and that higher levels of taxonomic re solution can be used to describe variations in the structure of benthic com munities at this spatial scale. (C) 2001 Elsevier Science Ltd. All rights r eserved.