New report urges food safety guidance on seaweed

FAO and WHO released a report today that reviews the food safety information currently available about seaweed harvested from both wild stocks and aquaculture and recommends further discussion as well as international guidance. The document reports that morbidities and mortalities linked to the consumption of seaweeds are rare, but cautions that the limited data raise concerns that certain hazards may be present in seaweed. These include: chemical hazards such as heavy metals (principally inorganic arsenic and cadmium), persistent organic pollutants (e.g. dioxins and polychlorinated biphenyls), radionuclides and pesticide residues; microbiological hazards (e.g. Salmonella spp., Bacillus spp., and norovirus); physical hazards (e.g. metal pieces, glass splinters, crustacean shells, micro- and nanoplastics); and allergens.

The Report of the Expert Meeting on Food Safety for Seaweed – Current status and future perspectives was consolidated during a joint FAO-WHO Expert Meeting on Seaweed Safety, which was held virtually on 28 and 29 October 2021. FAO and WHO developed this report to identify food safety hazards (microbiological, chemical and physical) linked to the consumption of seaweed and aquatic plants.

Among the recommendations are:

• the collection and evaluation of seaweed consumption data at national and regional levels;
• the monitoring of seaweed food and feed products for food safety hazards; and
• a risk assessment/risk profiling of the relevant seaweed hazard groupings to ascertain their public health significance.

FAO Fishery Officer Esther Garrido Gamarro explained that following these recommendations could support the development of Codex guidelines or standards at the international level as well as regional and/or national legislation. “In turn, the standards and policies would safeguard the production, processing and utilization of seaweed for food and feed while protecting the health of consumers,” she said, explaining that this analysis could provide a basis for undertaking further work in this area.

The production of seaweed, or marine macroalgae, has more than tripled in the past two decades -- increasing from 10.6 million tonnes in 2000 to 32.4 million tonnes in 2018. Global trade in seaweed and seaweed products amounted to USD 5.6 billion in 2019 alone. The demand for seaweed is expected to continue as the population grows and sustainable ways of producing food are sought. Seaweeds have long been used as foods in different parts of the world.

Many factors can affect the presence of hazards in seaweed, including: the type of seaweed, its physiology, the season in which it is produced, production waters, harvesting methods and processing.

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