Sediment-Free Myriophyllum spicatum Toxicity Test (OECD TG 238)
The Sediment-Free Myriophyllum spicatum Toxicity Test according to OECD TG 238 is designed to evaluate the effects of chemicals on aquatic vascular plants in a controlled, sediment-free environment. Myriophyllum spicatum (Eurasian watermilfoil) serves as a representative macrophyte species, important for primary production and habitat structure in freshwater ecosystems.
In this study, actively growing plant fragments are exposed to a range of concentrations of the test substance dissolved in water under controlled laboratory conditions for a period of typically 14 days. Growth inhibition is monitored by measuring endpoints such as increase in fresh weight, shoot length, or leaf area.
The test aims to establish concentration–response relationships and to determine key endpoints, including the median effective concentration (ErC₅₀) and the No Observed Effect Concentration (NOEC).
This assay provides essential data on the potential impact of chemicals on aquatic plant growth and productivity, supporting environmental risk assessment and regulatory decision-making for plant-protecting substances and other aquatic contaminants.
