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Using a modified dredging elutriate testing approach to evaluate potential aquatic impacts associated with dredging a large freshwater industrial harbor
Author(s) -
WatsonLeung Trudy,
Graham Matt,
Hartman Erin,
Welsh Paul G
Publication year - 2017
Publication title -
integrated environmental assessment and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 57
eISSN - 1551-3793
pISSN - 1551-3777
DOI - 10.1002/ieam.1790
Subject(s) - dredging , daphnia magna , environmental science , hyalella azteca , benthic zone , pimephales promelas , contamination , environmental chemistry , minnow , environmental engineering , fishery , toxicity , ecology , biology , fish <actinopterygii> , chemistry , organic chemistry , crustacean , amphipoda
Potential adverse impacts to the aquatic environment should be minimized whenever possible during an environmental dredging project by selecting realistic and technically feasible environmental targets. These targets need to balance short term impacts with the longer term benefit of removing contaminated sediments from the environment. Environmental dredging is part of the planned remediation of Randle Reef (a 60 hectare zone of mostly PAH‐contaminated sediments) in Hamilton, Ontario, Canada. In this study, we describe the results of dredging elutriate toxicity testing (DETE) to assess the potential risks from dredging this PAH contaminated site. A modified elutriate preparation method intended as an alternative measure of conditions within the dredging plume was assessed with both standard water column species ( Daphnia magna and fathead minnow [ Pimephales promelas ]) and alternative benthic and epibenthic test organisms ( Chironomus dilutus and Hyalella azteca ). The standard DETE test was also conducted with H. azteca to compare with the modified DETE results. The greatest toxic response was seen in the alternative test species; however, the modified DETE method resulted in less toxicity than the standard protocol. The relationship between toxicity results and chemical and/or physical characteristics of the samples was examined, but differences in toxicity could only be explained by differences in the total suspended solids concentrations in the elutriate samples. Challenges associated with DETE assessment of PAH‐contaminated sediments and the implications for establishing dredging benchmarks are discussed. Integr Environ Assess Manag 2017;13:155–166. © 2016 SETAC