Overview
ISO 17244:2015 - Water quality: Determination of the toxicity of water samples on the embryo‑larval development of Japanese oyster (Crassostrea gigas) and mussel (Mytilus edulis or Mytilus galloprovincialis) - specifies a standardized biotest for assessing the effects of chemical and aqueous samples on early life stages of marine bivalves. The method exposes fertilized eggs to test solutions under static conditions through the D‑shell larval stage to determine concentration‑response metrics (ECx, EC20, EC50) and effect thresholds (LOEC, NOEC). The test is suitable for coastal and brackish matrices and can be applied to chemicals, effluents, seawater, aqueous sediment extracts and petroleum product leachates.
Key topics and requirements
- Test organisms: Crassostrea gigas (Pacific/Japanese oyster) and Mytilus edulis or M. galloprovincialis (mussels).
- Salinity ranges: mussels 20–40; oysters 25–35 (salinity must be adjusted or dilutions limited accordingly).
- Exposure window: from fertilized eggs to D‑shell larvae - 24 h endpoint for oysters, 48 h for mussels.
- Endpoints assessed: abnormal larval development (shell deformation, hinge irregularities, mantle hypertrophy), developmental delay/arrest, and mortality. Results are reported as ECx (e.g., EC20, EC50), LOEC, and NOEC.
- Sample types: chemical substances/preparations, marine/brackish waters, streams and effluents (urban, agricultural, industrial), pore water, elutriates, eluates and leachates from sediments, and petroleum extracts.
- Method elements: gamete collection and spawning (thermal stimulation or stripping), reference seawater (natural or synthetic; hypersaline brine options noted), egg density measurement, fertilization/inoculation, incubation, microscopic observation, and analytical measurements.
- Quality/validity: prescribed validity criteria, performance data, and reporting requirements. Tests must be performed by suitably qualified personnel and follow laboratory safety practice.
Applications and users
- Environmental monitoring and compliance testing for coastal waters and effluent discharges.
- Ecotoxicology laboratories performing acute/sublethal toxicity screening using sensitive early life stages.
- Regulatory agencies, water quality managers, consultants and researchers conducting environmental impact assessments, sediment toxicity surveys, or assessing petroleum/product leachates.
- Aquaculture and hatchery facilities assessing water quality risks to bivalve production.
Related standards and context
- Normative references include ISO 5667‑16 (sampling guidance for biotesting) and ISO 14442 (algal growth inhibition test guidance). ISO 17244:2015 is aligned with historical ICES recommendations and adapts established embryo‑larval protocols for routine water quality assessment.
Keywords: ISO 17244, water quality, bivalve embryo‑larval toxicity test, Crassostrea gigas, Mytilus edulis, EC50, NOEC, effluent testing, sediment pore water, marine ecotoxicology.