Finally! CEFAS referrred me to Food Standards, who have come back with a very comprehensive reply. The first part is the usual sort of recital about commercial produce, but then it directly answers as best they can about foraging. Put here in full, maybe worth a Sticky? Any further queries, please go directly to them, and post query and reply.
Thank you for your query. I am replying on behalf of the Food Hygiene, Foodborne Disease and Products of Animal Origins team. (
foodhygiene.policy@food.gov.uk)
In response to your first question, Shellfish such as mussels, clams and oysters may potentially be unsafe to eat as they are filter feeders and are susceptible to contamination with bacteria, marine biotoxins or viruses from their environment.
Food Safety and Hygiene legislation ensures that commercial harvesting of shellfish protects public health. This legislation does not apply to foraging of shellfish for private consumption.
Food Businesses placing shellfish on the market carry out appropriate risk-based testing to ensure that shellfish are safe to eat. They will gather shellfish from areas which are monitored for faecal contamination e.g. from sewage discharges and classified accordingly by the competent authority which determines the appropriate level of post-harvest controls that need to be applied:
- Areas which are Class A are fit for direct human consumption,
- areas which are Class B require depuration (a process to remove bacterial contamination from the shellfish) in an approved establishment, and
- areas which are Class C require processing using permitted heat treatments in an approved establishment.
Most classified harvesting areas in England and Wales are Class B.
Classified production and relaying areas are also monitored for the presence of phytoplankton which can produce marine biotoxins which can be taken up by shellfish. Shellfish flesh is also tested routinely for marine biotoxins on a risk basis. Eating shellfish contaminated with marine biotoxins can cause serious illness.
Where results of routine testing in classified areas are above trigger levels, immediate action is taken by the Local Authority to protect public health which may involve the closure of the affected bed or a temporary classification downgrade which would ensure additional product treatment prior to shellfish being placed on the market for human consumption.
Classified harvesting areas are either ‘open’ fisheries where the shellfish stocks are not owned by commercial producers or are farmed with the stock owned by aquaculture businesses.
Routine monitoring of shellfish is not undertaken outside of classified areas and therefore they may not be safe to eat.
If you are intending on coastal foraging for shellfish, our general advice is as follows:
- Before setting out, check your local authority website or contact your local authority for information on whether:
- permission is needed before harvesting,
- there are any closure notices in place for classified harvesting areas as this may indicate that there are potential risks to public health,
- Areas are closed to harvesting to everyone for conservation purposes,
- Some LAs may provide guidance on foraging shellfish.
- Do not forage from or around any trestles or ropes, which likely indicates that the shellfish are owned by an aquaculture businesses.
- Do not forage near to sewage outfalls or in places where there is visible pollution or presence of algal bloom.
- Always make sure that any shellfish foraged are alive and have an undamaged shell. The shell should remain tightly closed or close when handled. Any dead shellfish should be discarded.
- After foraging ensure that any containers used allow for drainage as shellfish should not be transported in water or other liquid. You should also avoid exposing shellfish to extreme temperatures and when transporting you should try to limit any damage to the shell.
- Shellfish should be cleaned and rinsed before being stored in the fridge as soon as possible after foraging. If foraging oysters, these should be stored cup-side down.
- Foraged shellfish should be thoroughly rinsed with tap water and thoroughly cooked before consumption.
Additional information to be aware of:
- Although thorough cooking will generally kill bacteria and viruses that may be present, cooking will not destroy any biotoxins which may have been taken up by the shellfish during a Harmful Algal Bloom as these are heat-stable.
- Biotoxins can cause a range of symptoms such as nausea, vomiting and diarrhoea to paralysis in extreme cases that can lead to death.
- Biotoxins may be present all year round, but these are often more prevalent in between February and October.
In regard to the second question, unfortunately, we don’t have specific information on the safety of foraging different seaweeds in particular areas in the UK, however we advise you to take care to make sure that foods are gathered sustainably and are safe to eat. Local authorities may have advice on seaweed on their websites, so you can check these in case they have relevant information for your specific area.
We have general foraging tips for you to follow on our foraging page
Guidance for safe foraging | Food Standards Agency which highlights ways to keep safe when foraging for different types of food. Some of these will apply to the foraging of seaweed.
You should also note that there are legal aspects when foraging. Make sure you understand the rights to forage in an area. Local/National Heritage sites can provide relevant information dependant on geographical location. Much of the coastline is owned by The Crown Estate and allows for personal foraging in most areas, but some areas do have restrictions or require permits, so check this beforehand.
You can find your Local Authority here -
Contact a local food safety team | Food Standards Agency
Contact Natural England here -
enquiries@naturalengland.org.uk
Crown Estate website can be found here -
Seaweed harvesting | The Crown Estate
We hope you find this information useful,
Sally
Foodborne Disease Policy Advisor
Foodborne Disease Branch
Food Standards Agency
6th Floor | Clive House | 70 Petty France | London | SW1H 9EX
