A field‐based microcosm method to assess the effects of polluted urban stream sediments on aquatic macroinvertebrates

Abstract

A method using field-based microcosms was developed to determine the effects of contaminated sediments on aquatic macroinvertebrates. Fine sediments from nonpolluted, moderately polluted, and severely polluted bodies of water were placed in microcosms positioned within the littoral zone of a nonpolluted wetland near Melbourne (Victoria, Australia). In three experiments, 47 taxa, including 18 Chironomidae, 6 taxa from other Diptera families, and 7 Hemiptera taxa, colonized the microcosms, mostly via eggs deposited by flying adults. The effects of sediment type on the presence and abundance of common taxa were considered statistically. Pollution levels in sediments (indexed either by a principal components analysis or by the concentration of zinc, the predominant metal) resulted in reduced occurrence and abundance of eight taxa but had no effect on another five taxa. These findings were validated with an extensive field database for the distribution of macroinvertebrates and associated concentrations of zinc in sediments from streams and wetlands in the Melbourne region. The occurrence of eight taxa and the abundance of two taxa varied at similar zinc concentrations in sediments from both the microcosms and the field. Patterns for another two species did not match the microcosm results, but these groups contained multiple species with potentially diverse responses. The present results suggest that contaminant levels in sediments probably have a direct effect on the occurrence and abundance of macroinvertebrates in bodies of water in urban areas. The microcosm method can be used to gather information regarding the effects of sediment quality on macroinvertebrates in lentic habitats, particularly for indigenous species that cannot be easily reared or tested in laboratory conditions. Because almost all macroinvertebrates in microcosms develop from eggs, the most sensitive life stages (i.e., first and second instars) are exposed to polluted sediments.

Phylogenetic signals and ecotoxicological responses: potential implications for aquatic biomonitoring

“…Species may be better indicators of potential stressors and underlying causal mechanisms than families, if they show specific responses to their environment (Resh and Unzicker 1975;Riva-Murray et al 2002;Pettigrove and Hoffmann 2005;Carew et al 2007b). Species-level identification can yield substantially more information when sites are dominated by speciose families, like the Chironomidae (King and Richardson 2002) or in urban areas where there are only few speciose families (Beavan et al 2001).…”

The Parthenogenetic Cosmopolitan Chironomid, Paratanytarsus grimmii, as a New Standard Test Species for Ecotoxicology: Culturing Methodology and Sensitivity to Aqueous Pollutants

“…To initiate stocks for culturing trials, P. grimmii larvae and eggs were collected from Glynns Wetland, Warrandyte, Victoria, Australia (-37.739869°latitude, 145.195388°l ongitude) which is unpolluted (Pettigrove and Hoffmann 2005). Plastic tubs, containing water and sediment from Glynns Wetland, were set up following Pettigrove and Hoffmann (2005).…”

“…Plastic tubs, containing water and sediment from Glynns Wetland, were set up following Pettigrove and Hoffmann (2005). Chironomids were allowed to oviposit in these tubs for 1 month, after which the tubs were returned to an outdoor shade house and covered with stockings.…”

“…Toxicity results obtained with P. grimmii, unlike endemic species, are likely to be relevant to aquatic ecosystems around the world. This species is also relatively easy to source in the field, as it often dominates in terms of abundance in sediment microcosm experiments within Australasia (Pettigrove and Hoffmann 2005;Sharley et al 2008) and Europe (Colombo et al 2013). In addition, P. grimmii only consist of females (Porter 1971), meaning toxicity results cannot be confounded by sex-specific differences in pollution sensitivity as in Chironomus spp.…”

A preliminary study into the potential of mayflies (Ephemeroptera: Baetidae and Caenidae) as bio-indicators of stream health in Fiji

“…Experimental approaches of assessing direct effects of stream properties on mayfly growth and survival might involve standard laboratory multiple dose assays or an extended eco-toxicological 'semi-field' approach where nymphs captured at one site are maintained in mesh-bag mesocosms at another stream (e.g. Pettigrove and Hoffman, 2005). Future studies on the distributions of macroinvertebrate abundance and stream parameters in Fiji could be combined with laboratorybased toxicity tests in order to better understand the mechanisms behind any observed field associations (e.g.…”