Benthic Invertebrate Bioassays With Toxic Sediment and Pore Water

Abstract

The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtoxa, a 15-min assay of Photobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magna lethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexugenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna in pore water was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.

Comparisons between microscale and whole-sediment assays for freshwater sediment toxicity assessment

“…rather than anthropogenic chemicals. Despite the results obtained here, it should be noted that other researchers have documented good correspondence between the ToxiChromoPad and solid-phase Microtox endpoints and whole-sediment benthic invertebrate Ž endpoints Giesy et al, 1990;Winger et al, 1993;Day . et al, 1995a . Pore waters are often used in toxicity testing to Ž .…”

Review and comparison of available testing approaches and protocols for testing effects of chemicals on sediment‐dwelling organisms with potential applicability to pesticides

“…A number of different experimental approaches are applied to the assessment of sediment toxicity including the preparation and testing of sediment elutriates (Buton et al 1989), pore waters (Giesy et al 1990) and whole sediments with the latter either spiked with a specific test compound of interest in a concentration series (Roman et al 2007) or used to compare the relative toxicity of different environmental sites that are subject to a gradient of contamination. Although some tests use addition of test substance to the overlying water in sediment tests as a simulation of the entry route to the aquatic environment for the purpose of pesticide risk assessment the use of whole sediments spiked with the test pesticide is the most relevant procedure.…”

Effect of Food and Light on the Sensitivity of Copper and Zinc to Freshwater Benthic Ostracod Heterocypris incongruens

“…Sediment bioassays have proven to be a powerful tool for assessing sediment-related toxicity in coast and estuarine system (Araújo et al, 2010). Direct contact assays with benthic species are needed for an ecologically meaningful evaluation of the overall effects of sediment pollution on biological communities (Giesy et al, 1990;Burton et al, 1996). Several studies have described whole-sediment toxicity tests using a variety of organisms including amphipods (Riba et al, 2003), bacteria (Libralato et al, 2008), clams (Chung et al, 2007), and midges and oligochaete worms (Airas et al, 2008).…”