title: Benthic macroinvertebrates as indicators of environmental deterioration in a large microtidal estuary.
abstract: This study tested the hypothesis that, during recent years, the benthic macroinvertebrate fauna of the large basin of the Swan-Canning Estuary has changed in ways consistent with deteriorating environmental conditions in that estuary. Between 1986/7 and 2003/4, the compositions of that fauna altered markedly at the species and even family levels. Thus, the densities and number of species of molluscs, and especially of crustaceans, which are particularly susceptible to environmental stress, declined, while those of the more tolerant polychaetes increased. However, taxonomic distinctness declined consistently only at one of the four widely-spaced sampling sites and the dispersion of samples did not differ markedly between periods, indicating that the benthic fauna has not undergone such extreme changes as in the nearby Peel-Harvey Estuary. It is thus proposed that benthic macroinvertebrates can act as important indicators of the severity of environmental degradation in microtidal estuaries in regions where such perturbations are increasing.
authors.affiliation: Centre For Fish and Fisheries Research, School of Biological Sciences and Biotechnology, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia. michelle@oceanvision.com.au
authors.forename: M D
authors.initials: MD
authors.lastname: Wildsmith
authors.forename: T H
authors.initials: TH
authors.lastname: Rose
authors.forename: I C
authors.initials: IC
authors.lastname: Potter
authors.forename: R M
authors.initials: RM
authors.lastname: Warwick
authors.forename: K R
authors.initials: KR
authors.lastname: Clarke
mesh_terms: D000818:Animals; D044822:Biodiversity; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry; D007448:Invertebrates / Q000145:classification* / Q000254:growth & development; D011156:Population Density; D012621:Seasons; D012623:Seawater / Q000737:chemistry; D014876:Water Pollution / Q000706:statistics & numerical data