This article was featured in Eurofish Magazine 4 2026.
FAO, IOC-UNESCO and the IAEA have published new joint guidance on monitoring algal toxins in bivalve molluscs, covering harmful algal bloom surveillance and management of harvesting and production areas. Released in Rome, the document aims to help competent authorities, laboratories and food safety bodies build monitoring programmes tailored to each production area’s risk profile. The guidance arrives amid rapid growth in the bivalve sector, where global production rose 49% between 2011 and 2023, while international trade increased by around 41% over the same period. The Mediterranean, where mussels, clams and oysters underpin both local economies and export chains, is highlighted as particularly affected by harmful algal blooms linked to ocean warming, eutrophication and local oceanographic shifts.
The document points out that toxic algae don’t always provide reliable early warning, as bivalves can exceed legal toxin limits even when cell counts are low. The guidance therefore recommends combining water-based microalgae monitoring with toxin testing in shellfish flesh, alongside fixed sampling points, local risk profiling, and clear closure/reopening protocols. Areas closed for excessive toxin levels should reopen only after consecutive clean results at least 48 hours apart. The document reinforces operators’ responsibility for product safety, emphasising traceability and rapid communication, especially for shellfish destined for international markets with strict compliance requirements.
