Sediment Ecotoxicology

About Sediment Ecotoxicology Services:

Sediments play an important role in aquatic ecosystems since they serve as a source and sink for organic and inorganic materials. Sediment toxicity tests and bioassays are important tools for regulators and scientists researching toxicity, bioaccumulation and bioavailability of chemicals to benthic organisms. Sediment ecotoxicity testing is considered rather complex as the properties of both the sediment matrix and compound being tested can greatly effect bioavailability to benthic organisms. Benthic organisms include, aquatic insect larvae, amphipods, molluscs and aquatic worms. These organism groups are important links in the food web and also have the ability to affect the structure and biogeochemical processes of aquatic ecosystems. Consequently, an accurate assessment of a compound’s potential exposure and toxicity to benthic organisms is imperative for regulatory purposes.    

Smithers-lake reflecting mountains

Smithers Viscient’s Sediment Ecotoxicology Expertise:

Smithers Viscient has been successfully conducting both acute and chronic sediment toxicity testing following applicable OECD/EPA guidance for several decades, using both radiolabelled and non-radiolabelled study designs. As these test methods have evolved, senior scientists at Smithers Viscient have worked closely with both industry and government agencies on revisions to existing guidelines. Smithers Viscient has standard procedures in place for preparing, dosing and equilibrating sediment in order to consistently conduct exposures at the appropriate concentrations. Our group is experienced in working with benthic organisms during sensitive life stages in order to conduct exposures that meet all relevant guidance acceptability criteria. The analytical group at Smithers Viscient also has significant experience in quantifying materials at low levels in challenging matrices such as highly organic sediments and pore water.

Smithers Viscient has independently developed an optimized test method for conducting Leptocheirus plumulosus  28-day chronic sediment toxicity tests, resulting in a revised methodology capable of producing more reliable and robust data with fewer failures. This type of study, which historically has been known to pose challenges in terms of variability of growth and reproduction in the test amphipods, as well as achieving survival criteria, is one of the primary methods for testing sediment toxicity. View the full press release to learn more.

Smithers Viscient’s sediment testing development and validation experience includes:

  • U.S. EPA (1989). Developed and validated test procedures with the marine amphipod Ampelisca abdita for use in measuring sediment quality
  • BBA Guidelines (1994). Participated in an international ring-test to evaluate midge emergence in a long-term toxicity test with Chironomus riparius
  • Environment Canada (1996). Participated in an inter-laboratory ring-test to develop and standardize a 14-day sediment exposure with Hyalella azteca
  • U.S. EPA (1996). Participated in an inter-laboratory evaluation of U.S. EPA sediment acute toxicity test methods with Hyalella azteca and Chironomus tentans
  • U.S. EPA (1996-1997). Participated in development and evaluation of chronic test methods for Hyalella azteca and Chironomus tentans
  • OECD 225 Lumbriculus test methods
  • Long-term toxicity test with Chironomus riparius for validation of OECD 233 Guideline
  • Inter laboratory 42-day chronic Hyalella azteca testing


Sediment Ecotoxicology Guidelines:

  • OECD 218: Sediment-Water Chironomid Toxicity Using Spiked Sediment
  • OECD 219: Sediment-Water Chironomid Toxicity Using Spiked Water
  • OECD 225: Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment
  • OECD 233: Sediment-Water Chironomid Life-Cycle Toxicity Test Using Spiked Water or Spiked Sediment
  • OECD 315: Bioaccumulation in Sediment-dwelling Benthic Oligochaetes
  • Ecological Effects Test Guidelines OPPTS 850.1735 Whole Sediment Acute Toxicity Invertebrates, Freshwater
  • Ecological Effects Test Guidelines OPPTS 850.1740 Whole Sediment Acute Toxicity Invertebrates,Marine
  • EPA 600/R-99/064. March 2000. Test Method 100.4: Hyalella azteca 42-day (chronic) Test for Measuring the Effects of Sediment-associated Contaminants on Survival, Growth, and Reproduction
  • EPA 600/R-99/064. March 2000. Test Method 100.5: Life-cycle Test for Measuring the Effects of Sediment associated Contaminants on Chironomus dilutus
  • U.S. EPA Test Method 600/R-01/020. Method for assessing the chronic toxicity of marine and estuarine sediment associated contaminants with the amphipod Leptocheirus plumulosus


Sediment Ecotoxicology Equipment and Instrumentation includes:

Smithers Viscient’s sediment laboratory expansion project has increased capacity of flexible testing space by 30%.

We have custom built rollers to provide sufficient mixing and equilibration of materials in sediment matrices. Furthermore, we have standard procedures for preparation of formulated sediment and reliable sources of both natural freshwater and marine sediment for use in testing.