ISO 17244:2025

Overview

ISO 17244:2025 - Water quality - specifies a standardized embryo‑larval bioassay to determine the toxicity of chemical and aqueous samples on the early development of marine bivalves: the Japanese oyster (Magallana gigas) and the blue mussel (Mytilus edulis or M. galloprovincialis). The method measures concentration levels that cause developmental abnormalities and is suitable for routine marine toxicity testing across defined salinity ranges (20–40 PSU for mussels; 25–35 PSU for oysters). The 2025 second edition updates the 2015 protocol, adds a sediment direct‑contact protocol (Annex C), adopts the revised oyster nomenclature, and permits extending test duration up to 48 h.

Key Topics

• Test organisms and conditions
  • Use of mature bivalves for gamete collection; guidance on spawning and fertilization.
  • Acceptable salinity and temperature ranges for valid tests.
• Sample types covered
  • Chemical substances and preparations, marine/brackish waters, effluents, aqueous extracts (pore water, eluates, leachates), and contaminated sediments (Annex C).
• Test procedure essentials
  • Collection/preparation of samples, selection of concentration ranges, gamete collection, fertilization, incubation, and observation of embryo‑larval development.
• Endpoints and metrics
  • Developmental abnormalities as the primary endpoint; expression of results using effect concentrations (ECx) and LOEC.
• Quality and reporting
  • Validity criteria, analytical measurements during tests, and required contents of the test report.
• Normative and informative references
  • ISO 5667‑16 is referenced for sampling and biotesting guidance; performance data and intercalibration history are provided.

Applications

• Environmental monitoring of coastal and estuarine water quality using bivalve bioassays.
• Regulatory and compliance testing of industrial, agricultural, and municipal effluents discharged to marine environments.
• Risk assessment of chemicals, petroleum products, and sediment/dredged material that may affect early life stages of marine bivalves.
• Research and inter‑laboratory studies assessing acute teratogenic effects and deriving toxicity thresholds (EC10/EC25/EC50, LOEC).

Who should use this standard

• Environmental testing laboratories and aquaculture hatcheries
• Regulatory agencies and environmental consultants
• Researchers in marine ecotoxicology and sediment assessment
• Organizations performing compliance testing for effluent permits and dredging projects

Related Standards

• ISO 5667‑16 (sampling - guidance on biotesting of samples)
• Referenced ICES recommendations and ISO definitions (e.g., ECx, LOEC) are used for consistent reporting and interpretation.

Keywords: ISO 17244:2025, water quality, embryo‑larval toxicity test, Magallana gigas, Mytilus edulis, bivalve bioassay, marine toxicity testing, sediment toxicity, effluent testing.