Lit Review: Cyanobacterial toxins in fish arising from cyanobacterial bloom

This literature review being tendered links into the FSA Strategy 2022 – 2027. This strategy states that the FSA’s fundamental mission is food you can trust. The FSA will continue to protect consumers by ensuring that food is safe and is what it says it is. This proposed piece of work is part of a wider programme of work and will sit in the Chemical Hazards in Food and Feed research programme. This is one of the FSA’s Areas of research interest | Food Standards Agency (ARI) and sits under ‘Research priority two: chemical, radiological and food hypersensitivity risks–How will dietary and other consumer-driven shifts in the food system change chemical, radiological and allergen risk over the next 5 years and how can we better anticipate them?’. The main aim of the area of interest (ARI) is to provide evidence to support effective risk management decisions by ensuring the risk analysis process is informed by independent, science-led risk assessment and socio-economic analytical evidence. Research under this ARI, including surveys and other research projects, will provide FSA scientists and policymakers with current and reliable information on chemicals in food and feed.

Lough Neagh in Northern Ireland is the largest freshwater lake in Ireland and Britain, measuring 400 square km. During the summer and autumn of 2023, 2024 and 2025, Lough Neagh has been affected by cyanobacterial blooms. Cyanobacterial blooms are expected to continue to occur in Lough Neagh, resulting in the presence of cyanobacterial toxins in fish and possible other foods. The types of toxins detected, and their concentrations, are expected to vary over time.

The objectives of this literature review are to fill in the data gaps regarding occurrence and toxicity through food and feed of cyanobacterial toxins in fish and other foods arising from cyanobacterial blooms. This literature review will consider the toxins that are currently being tested for as part of the ongoing monitoring programme (free and total microcystins, anaxtoxins, cylindrospermopsins and saxitoxins) as well as any other potential toxins, including anabaenopeptins which have recently been detected in the water in Lough Neagh. This piece of work will also enable the FSA to ensure all relevant contemporary scientific evidence is taken into account during the completion of our risk assessments for food and feed.

This literature review is required to consider the most up-to-date scientific literature of the occurrence and toxicity through food and feed of cyanobacterial toxins in fish and other foods. As a part of this review, it would be critical to determine the latest knowledge on the toxicity of these toxins and the levels of their occurrence, sites of occurrence and bioaccumulation in fish species relevant to those found in Lough Neagh as well unidentifiable peaks which may contain other toxins. Information about the accumulation of toxins from year to year in fish within the same water body that is affected by recurring algal blooms would be useful as well as insights as to how toxin levels may vary by the age or size of the fish.

In addition, knowledge of their occurrence and/or combined toxicology in wildfowl, waterfowl and other food products, such as meat and milk from cows exposed by living on or around waterways affected by cyanobacterial blooms and/or consuming the blue green algae material would be beneficial.

Information on the susceptibilities of various animal species such as zoo animal species which consume fish from Lough Neagh would be very useful. Information in relation to the seasonal patterns of blue green algae (i.e. when they are most potent) will further help to support and inform future sampling monitoring programmes. An understanding of what other countries are detecting in relation to cyanotoxins in fish or other foods and what action they are taking in relation to this would be beneficial.

Other potential sources of contamination in these blue green algae affected waters and the extent to which cyanotoxins can accumulate in these sources such as sediments which when disturbed may release cyanotoxins in the water resulting in exposure by fish and other aquatic wildlife have not been considered previously and would be beneficial to be considered as part of this literature review.

Once a literature review has been completed, the FSA and a scientific advisory committee (SAC), the Committee on Toxicology of Chemicals in Food, Consumer Products and the Environment (COT), will evaluate the data gathered and use it to inform future risk assessments and risk management and wider regulatory policy decisions and guidance.