Nematode biomass and allometric attributes as indicators of environmental quality in a Mediterranean harbour (Ligurian Sea, Italy)

Nematode biomass and allometric attributes (size spectra, body length and width, morphotypes) were measured and related to the environmental quality of sediments of the Genoa-Voltri commercial harbour (Ligurian Sea, NW Mediterranean) to investigate their possible use as ecological indicators. The sediment quality was defined by measuring the level of organic enrichment (quantity and biochemical composition of sedimentary organic matter) and oxygen stress (redox potential). de biomass spectra (NBS) proved to be extremely valuable in determining differences in the environmental quality of sediments on a hundred-metre spatial scale. High peaks of the NBS were observed in the more organic-rich and oxygen-stressed stations probably in relation to a lower diversity of the nematode communities in these stations, with the predominance of tolerant genera such as Paracomesoma and Sabatieria. Among allometric variables, the length was found to be negatively correlated with oxygen concentrations and positively with TOM percentages, whilst the morphotype length/width ratio (L/W) resulted negatively related to oxygen concentrations and organic matter quality (protein:carbohydrate ratio), suggesting that these allometric attributes represent indicators of the functional adaptation of nematodes to the changing environmental conditions. gest that in contrast to time-consuming and expertise-requiring nematode taxonomic analysis, biomass and allometric attributes analysis can provide a simpler but comparable tool to assess sediment quality and environmental heterogeneity of harbour ecosystems.