Specialty Toxicity Testing
EnviroScience biologists have extensive experience with culturing and examining many different species of freshwater, saltwater, and sediment test organisms. EnviroScience toxicologists can customize study plans to meet numerous requirements for specialty projects that can be successfully utilized to meet the needs of each individual client. Contact our Bioassay Laboratory in order to develop testing designed to address the specific needs of non-standard projects.
Sediment Toxicity Testing
Aquatic sediments at the bottom of lakes, streams and rivers can act as sinks for chemical compounds such as nutrients, metals, PAHs (polynuclear aromatic hydrocarbons) and PCBs (polychlorinated biphenyls). Sediments from many streams and rivers have received high concentrations of chemical contaminants, which over time present unacceptable risks to humans and aquatic biota. Many aquatic organisms are benthic (bottom-dwelling), meaning that they dwell in or on top of the sediments, and therefore come in direct contact with contaminants bound in the substrate. Whole sediment toxicity testing can be used as a tool to predict whether sediments will have adverse effects on benthic biota.
Whole sediment testing utilizes the sediment-dwelling organisms, Chironomus dilutus and Hyalella Azteca, to establish sediment quality from areas of ecological concern. These test organisms are exposed to field-collected sediments in the laboratory under controlled conditions. Artificial sediment is used as a laboratory control, thereby creating a standard against which test quality and test organism response can be compared.
The behavior of the organisms, including sediment avoidance and mortality, is monitored on a daily basis (USEPA 2000). In order to measure toxicity, a specific biological endpoint (mortality, reduction in growth) is used to assess the response of the organisms to contaminants in the sediments. Whole sediment testing integrates the effects of all sediment contaminants and any synergistic, additive or antagonistic interactions that occur between them.
Elutriate Testing
Elutriate bioassays provide another method for assessing the potential toxicity of sediments in aquatic systems. Elutriate testing identifies harmful toxins within the sediment that can ultimately affect aquatic organisms living in the water column. ES biologists follow the procedures for elutriate testing outlined in US EPA 503/8-91/001, in which site sediments are combined with laboratory water to solubilize components present in the sediment. Test organisms are exposed for a specified amount of time, depending on whether acute or chronic endpoints are required.
Product Testing
Product testing is a useful tool to obtain aquatic toxicity data to be included on a Material Safety Data Sheet (MSDS). Product testing is also used to obtain an EcoLogo. An EcoLogo is a seal of approval that is printed on a certified product’s label, designating the product as eco-friendly. Numerous methods and species can be utilized depending upon your required endpoints. Common product testing species include Ceriodaphnia dubia (water flea), Daphnia magna (water flea), Pimephales promelas (fathead minnow), Oncorhynchus mykiss (rainbow trout), and Selenastrum capricornutum (green alga).
Brine Studies
Brine water is a by-product of hydraulic fracturing or “fracking”, which is a way of extracting oil and natural gas from shale deposits. Brine Studies provide a method for determining the level of toxicity that brine water, discharged by a treatment plant or major discharger, may have on an aquatic environment. A brine study is designed to determine at what concentration the brine water may be discharged to minimize the effect on the receiving water quality. These studies additionally ensure that the aquatic organisms are not affected by the addition of brine water into the water system.
7 day Ceriodaphnia dubia Chronic Bioassay
Please contact janderson@enviroscienceinc.com for more information on any specialty testing that you may need.
