Legacy and Current‐Use Contaminants in Sediments Alter Macroinvertebrate Communities in Southeastern US Streams

Abstract

Sediment contamination of freshwater streams in urban areas is a recognized and growing concern. As a part of a comprehensive regional stream‐quality assessment, stream‐bed sediment was sampled from streams spanning a gradient of urban intensity in the Piedmont ecoregion of the southeastern United States. We evaluated relations between a broad suite of sediment contaminants (metals, current‐use pesticides, organochlorine pesticides, polychlorinated biphenyls, brominated diphenyl ethers, and polycyclic aromatic hydrocarbons), ambient sediment toxicity, and macroinvertebrate communities from 76 sites. Sediment toxicity was evaluated by conducting whole‐sediment laboratory toxicity testing with the amphipod Hyalella azteca (for 28 d) and the midge Chironomus dilutus (for 10 d). Approximately one‐third of the sediment samples were identified as toxic for at least one test species endpoint, although concentrations of contaminants infrequently exceeded toxicity benchmarks. Ratios of contaminant concentrations relative to their benchmarks, both individually and as summed benchmark quotients, were explored on a carbon‐normalized and a dry‐weight basis. Invertebrate taxa measures from ecological surveys tended to decline with increasing urbanization and with sediment contamination. Toxicity test endpoints were more strongly related to sediment contamination than invertebrate community measures were. Sediment chemistry and sediment toxicity provided moderate and weak, respectively, explanatory power for the similarity/dissimilarity of invertebrate communities. The results indicate that current single‐chemical sediment benchmarks may underestimate the effects from mixtures of sediment contaminants experienced by lotic invertebrates. Environ Toxicol Chem 2020;39:1219–1232. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.

Characterisation of Benthic Macroinvertebrate Communities in Small Watercourses of the European Central Plains Ecoregion and the Effect of Different Environmental Factors

“…This may be the cause of the observed differences in the environmental conditions among the watercourses we studied. Changes in environmental conditions as a result of land use may lead to a decrease in biodiversity, biomass, and density of sensitive species of aquatic animals, thereby leading to changes in the biotic composition [ 47 , 49 ]. Small watercourse ecosystems are especially sensitive to the anthropopressures noted above [ 50 ].…”

Streambed pollution: A comprehensive review of its sources, eco-hydro-geo-chemical impacts, assessment, and mitigation strategies

“…One such study attempted in several Danish lowland streams discovered considerable concentrations of pesticides and heavy metals in the streambed sediments [53]. In Gasconge region of France, enrichment of several heavy metals including Copper, Lead, Cobalt and Zinc have been reported in both the forested and in the downstream of the cultivated catchments due by the deposition of industrial and petrochemical combustions and fertilizer usage, respectively [54].…”

“…Similarly, pesticide and sewage pollution of streams has been observed to alter the community structure of macroinvertebrates with reduction in biodiversity as the marked feature [143,144,145]. Toxic inorganic and organic substances associated with fine sediments have been also demonstrated to negatively influence the macroinvertebrates species in streams [54,138,144]. Further, the heavy metals and hydrocarbons attached with the deposited sediments could also be transported to overlying water and can influence the non-benthic species such as fish or vegetation.…”

Traffic-related sources may dominate urban water contamination for many organic contaminants

“…Stormwater runoff is more associated with nonpoint contaminant sources and can be responsible for the transport of diverse groups of contaminants including nutrients, bacteria, metals, microplastics, and organic contaminants to streams during runoff events [4][5][6][7]. Legacy contamination and wet and dry atmospheric deposition, though less important, have also been associated with urban stream contamination for metals and organic pollutants [8][9][10][11].…”