Response of macroinvertebrates to copper and zinc in a stream mesocosm

Abstract

Metal pollution of streams and rivers is recognized as one of the major concerns for management of freshwaters. Macroinvertebrate communities were established within 12 artificial streams and exposed to three replicated concentrations of a metals mixture (copper and zinc) for 34 d. The cumulative criterion units (CCU = sigma[metals]/hardness-adjusted U.S. Environmental Protection Agency [U.S. EPA] 1996 chronic criterion value) of total metals in the low, medium, and high treatments were 2.4, 5.9, and 18 CCUs. Zinc comprised approximately 75% of the CCUs in each of the treatments. Effects on taxa richness and the number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) were moderate at the high exposure concentration (-23% and -26% respectively, p < 0.05). All of the five major mayfly species showed near extinction, whereas four of the seven caddisflies showed stimulation (up to +121%) and three were reduced (up to -76%). Redundancy analysis for this metal gradient indicated that 94% of the variance in community structure was explained by three quantitative variables: total mayfly abundance, a mollusk (Potamopyrgus antipodarum) abundance, and the number of EPT individuals, indicating that multiple indices do provide improved predictors of metal stress. Most species showed a threshold response relationship, whereas some community indicators showed apparent hormetic responses (e.g., number of mayfly taxa, total taxa, and number of EPT taxa). Model concentration-response relationships with generalized linear models were used to provide threshold of 20% effective concentration values for species and community metrics. Threshold effect values ranged upwards of 1.4 CCUs, indicating that U.S. EPA chronic criteria would be protective of species and community responses.

An integrative assessment of environmental degradation of Caveira abandoned mine area (Southern Portugal)

“…This criterion has been already applied to analyse the response of different organisms to metals in streams (Clements et al, 2000;Hickey and Golding, 2002;Hirst et al, 2002). The authors have followed the USEPA chronic criterion values for Al (87 μg L −1 ), Fe and Mn (1000 μg L −1 ), whilst the criterion values for Ag (1.…”

Ffectiveness of Using River Insect Larvae as an Index of Cu, Zn and as Contaminations in Rivers, Japan

“…Many papers concerning metal concentration in river insect larvae and the high concentration factor of heavy metal found in many kinds of insects have been published [1], [2], [3]. In particular, the influence of metal from waste water or mine tailings on river insects and the relation between metal concentrations in soil and water and metal concentration on insects have been studied [4], [5].…”

Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms

“…The use of controlled semi-field exposures, such as mesocosms, provides an opportunity to perform ecosystem-level research that can complement laboratory bioassays and, therefore, better predict effects of ecological relevant exposures of different types of anthropogenic substances to natural communities (Fairchild et al, 1992;Culp et al, 2003;Hickey and Golding, 2002;Van den Brink, 2006;Van den Brink et al, 2005). Mesocosms are smaller and less complex than natural ecosystems, yet they allow the use of relevant biological conditions (ambient abundance of natural biota), while maintaining the statistical power through replication of treatments and precise regulation of pesticide concentrations and other physico-chemical variables (Baird et al, 2001;Crane, 1997).…”