Complex relationships between shallow muddy benthic assemblages, sediment chemistry and toxicity in estuaries in southern New South Wales, Australia. Issue 2 (April 2018)

• Record Type: Journal Article
• Authors: Birch, G.F.; O'Donnell, M.A.; McCready, S.
• Is Part Of: Marine pollution bulletin. Volume 129:Issue 2(2018)
• Page Start: 573
• Page End: 591
• Publication Date: 2018-04
• Subjects: Sediment quality guidelines -- Contamination -- Impaired sediments -- Sydney estuary -- Biologic response -- Diversity; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2017.10.033
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Synoptic sediment quality triad (contaminants, benthic assemblages, toxicity testing) data were collected for sites in Sydney estuary, adjacent Cooks River and five less-modified southern estuaries. Matching data tested relationships between contaminants and benthic assemblages, correlations with specific contaminants, and the ability of sediment quality guidelines to predict the risk of adverse effects. Significant but weak relationships occurred in complex patterns between assemblages, contaminant concentrations and environmental variables. Maximum benthos abundance occurred where sediment contamination was high and was dominated by polychaetes. Spionidae (polychaete) and Galeommatidae (mollusc) abundances were strongly correlated with site environmental characteristics and with varying mixtures of metals and organic contaminants. The risk of adverse effects on benthic assemblage structure increased with increasing sediment toxicity except for areas of very high contamination and for non-bioavailable anthropogenic chemicals. The overall weight-of-evidence scores differentiated the highly modified sites from less-contaminated southern estuaries, where toxicity scores were higher than predicted. Graphical abstract: Non-metric MDS plot of relationships between benthic biotic samples and contamination categories showing replicate benthic samples. Large abundances of polychaetes in the families Spionidae, Capitellidae and Hesionidae and the bivalve mollusc families Galeommatidae and Semelidae contributed to significant differences in community composition in most contamination categories. Highlights: A rare, large synoptic set with matching sediment chemical concentrations, toxicological data and benthic assemblages. Muddy estuarine sediments classified post hoc into four categories based on overall concentration of contaminants. Benthic abundance dominated by polychaete worms and increased with increasing sediment contamination, but not monotonically. Number of taxa did not differ, taxa responded differently to differing magnitude and combinations of sediment contaminants. Sediment quality guidelines predicted increased risk of sediment toxicity but weight-of-evidence approach less accurate.