UK Commercial Shellfish Harvesting Rules
What rules apply to commercial shellfish harvesting in the UK?
Commercial harvesting of bivalve shellfish (mussels, oysters, cockles, clams, scallops) in the UK falls under two sets of rules. Food hygiene law says you may only harvest from areas the regulator has classified (Class A, B or C, by E. coli level in the flesh). Each class decides whether the catch can be sold straight for eating or must first be purified, relayed or cooked, and it must meet the marine biotoxin limits. Fisheries law then controls who may fish, with what gear and where, through vessel licences and shellfish permits, several/regulating orders and minimum sizes.
Approach: I read the hygiene and official-controls regulations (EU Regulation 853/2004 Annex III Section VII, Implementing Regulation 2019/627) and the Food Safety Act 1990 in the datasets. I also read FSA, Food Standards Scotland, MMO and Defra guidance on GOV.UK and foodstandards.gov.scot. The datasets hold the EU consolidated text (dated 7 May 2026), not the GB-assimilated version, and I couldn't open the GB text on legislation.gov.uk. So where EU and GB differ, I give the UK regulators' guidance.
1. Who classifies and monitors
- England, Wales and Northern Ireland: the FSA is the Central Competent Authority for classification and official-control monitoring (GOV.UK, Shellfish controls information).
- Northern Ireland: you apply to FSA in NI for classification of a harvesting area (GOV.UK NI).
- Scotland: Food Standards Scotland classifies and monitors areas. Applications go through the Shellfish Monitoring and Classification (SMC) system (FSS).
- Before classifying an area, the authority "shall carry out a sanitary survey" of pollution sources [1]. In England and Wales, provisional classification needs 12 samples over 6 months, and full annual classification needs 12 months of data (GOV.UK, Shellfish classification).
2. Where you may harvest
- Gatherers "may only harvest" live bivalve molluscs from production areas with fixed boundaries that the competent authority has classified A, B or C [2].
- Operators "must not" produce or harvest in areas that are unclassified or unsuitable for health reasons. They must use own-check and authority information, including weather and environmental conditions, to decide how each batch should be treated [2].
| Class | E. coli standard (per 100 g flesh and intravalvular liquid) | What you may do with the catch |
|---|---|---|
| A | 80% of samples ≤230; the other 20% ≤700 [3] | Sell for direct human consumption if Chapter V health standards are met [2] |
| B | 90% ≤4,600; the other 10% ≤46,000 [4] | Sell only after purification or relaying [2]; FSA guidance also allows heat treatment |
| C | All ≤46,000 [5] | Sell only after long-period relaying [2] or approved heat treatment |
| Prohibited | Results above 46,000 | No harvesting (GOV.UK) |
Relaying periods differ by source:
- The EU text sets relaying of at least two months, unless the authority agrees a shorter period based on the operator's risk analysis [2].
- FSA guidance for England, Wales and NI is more specific. Class B can be relayed in a Class A area for at least 1 month. Class C needs 2 months' relaying in Class B plus purification, or 2 months in Class A, or heat treatment (GOV.UK).
- FSS says Class C must be relayed for at least 2 months or cooked by an approved method (FSS).
Approved heat treatments for unpurified B/C molluscs include sterilisation in sealed containers, or immersion in boiling water until the flesh reaches at least 90 °C, held for at least 90 seconds [2].
3. Harvesting, handling and relaying
- Harvesting must not cause extra contamination or excessive damage to shells. Operators must protect the molluscs from crushing and extreme temperatures, must not re-immerse them in contaminating water, and may use only Class A areas for conditioning in natural sites. Transport must drain well and protect against contamination [2].
- Relaying is allowed only in approved, clearly marked areas, on an "all in, all out" basis, with permanent records of source, period and destination [2].
4. Paperwork and routing to market
- Registration document: every batch moved between areas or establishments must travel with one. It must state the gatherer's identity and address, harvest date, production area location, the area's health status, species and quantity, and destination [2].
- Keeping copies: keep a copy for at least 12 months. Receivers must date-stamp it. It may be dispensed with only where the gatherer also runs the receiving establishment, one authority supervises everything, and that authority permits it [2].
- Dispatch centre: no retail sale is allowed "otherwise than via a dispatch centre", where an identification mark is applied. Dispatch centres may take molluscs only from Class A areas, relaying areas, purification centres or other dispatch centres [2].
- Labels: must be waterproof and show the species (common and scientific name) and the packing date. The retailer keeps the label for 60 days [2].
- Intermediary operators (traders between areas and establishments): the EU text now has registration and approval rules for them [2]. These came in by a later EU amendment, and I couldn't confirm that the GB text includes them.
5. Biotoxins, closures and reopening
- Limits: PSP 800 µg saxitoxin equivalents/kg; ASP 20 mg domoic acid/kg; okadaic acid and dinophysistoxins 160 µg OA equivalents/kg; yessotoxins 3.75 mg/kg; azaspiracids 160 µg/kg [2].
- FSA guidance gives the same figures, but its okadaic acid group also includes pectenotoxins. It also states that FBOs are responsible for making sure their products comply (GOV.UK, Biotoxin monitoring).
- Sampling: toxin sampling is weekly during harvesting periods, unless a risk assessment justifies a different frequency [6].
- Closure: authorities "shall close" an area where health standards are not met [7]. The FSA and the local authority act together to close areas (GOV.UK).
- Reopening: after a biotoxin closure, an area normally reopens only after two consecutive results below the limit, at least 48 hours apart [8].
- E. coli action states: for these (England, Wales and NI), two satisfactory samples at least 7 days apart restore the previous class (GOV.UK).
6. Scallops, gastropods and echinoderms harvested outside classified areas
These may be sold only through a fish auction, dispatch centre or processing establishment. They must meet the Chapter V standards, shown by own checks [2].
7. Food Safety Act 1990 (England, Wales and Scotland)
- Regulations under the Act may prohibit or regulate the sale of shellfish taken from designated beds or layings (Schedule 1, paragraph 2(2)) [9].
- Food authorities "may" provide tanks for cleansing shellfish (section 24) [10].
8. Fisheries rules
- Licences and permits: a shellfish permit "allows you to fish for shellfish". Vessels without one may land only up to 5 lobsters or crawfish and 25 crabs a day (pots or nets only), or shellfish bycatch from towed gear up to 10% of the catch by weight. Over-10 m vessels dredging for king scallops need a scallop permit. Mussel-seed dredging is limited to vessels registered with the MMO or the Welsh Government (MMO, Fishing vessel licence types).
- Several and regulating orders (Sea Fisheries (Shellfish) Act 1967; England and Wales): a several order gives an exclusive right to fish or cultivate named shellfish in an area. A regulating order gives the right to manage that fishery through licences (Defra).
- Minimum sizes and closures: the MMO's Blue Book lists the crustacean size orders and scallop orders. It says it is not comprehensive for Welsh, Scottish and NI waters (Blue Book). I did not open local IFCA byelaws, so I give no district size figures.
Current area lists for England and Wales are in the FSA Classification List of 1 October 2026 (xlsx). If you tell me the location and species, I can look up that area's class and recent biotoxin results.
How are harvesting areas classified and checked for biotoxins?
The competent authority classifies harvesting areas. It first runs a sanitary survey of pollution sources, then grades each area Class A, B or C by the E. coli level in mollusc flesh. Once an area is classified, the authority keeps monitoring it. It tests the water for toxin-producing plankton and tests the molluscs for biotoxins, normally every week during harvesting periods. If results fail, the area is closed, and it reopens only after clean results.
Approach: I read Commission Implementing Regulation (EU) 2019/627, Articles 52 to 66 and Annexes IV and V, which set out how areas are classified and monitored. This is the EU text as first adopted. I did not check the GB-assimilated version, so the UK regulators' guidance (FSA, Food Standards Scotland) covered in my last answer still governs local practice.
1. Classification
Step 1: sanitary survey. Before classifying an area, the authority "shall carry out a sanitary survey" that covers [1]:
- an inventory of human and animal pollution sources;
- the amounts of organic pollutants released at different times of year, allowing for seasonal population changes, rainfall and waste-water treatment;
- how pollutants move with currents, depth (bathymetry) and the tidal cycle.
Food business operators (FBOs) may help with the survey on the authority's terms [1].
Step 2: monitoring programme. The authority builds a sampling programme based on the survey. The number of samples, where they are taken and how often must make the results representative of the area [11]. The authority must also have a procedure to make sure the survey and the programme are representative [12].
Step 3: boundaries and grading. The authority fixes each area's boundaries and grades it by faecal contamination, judging the sampling data over a review period that it sets [13]:
| Class | E. coli per 100 g flesh and intravalvular liquid | Outcome |
|---|---|---|
| A | 80% of samples ≤230; the other 20% ≤700. One unusual result above 700 may be set aside after a risk assessment based on an investigation | Direct human consumption [3] |
| B | 90% ≤4,600; the other 10% ≤46,000 | Only after purification or relaying [4] |
| C | All ≤46,000 | Only after relaying over a long period [5] |
- Test method: the reference method for E. coli is the ISO 16649-3 MPN (most probable number) technique. Other methods may be used if they are validated against it under ISO 16140 [14].
- Public list: the authority must keep an up-to-date list of classified areas, with their boundaries and class, and share it with producers, gatherers, purification centres and dispatch centres. It must tell them "immediately" of any change or closure [15].
2. Ongoing monitoring of classified areas
The authority must check classified areas periodically for four things [16]:
- malpractice over where molluscs come from and where they go;
- microbiological quality;
- toxin-producing plankton in the water and biotoxins in the molluscs;
- chemical contaminants.
Sampling plans run at regular intervals, or case by case where harvesting is irregular [6].
3. Biotoxin and plankton checks
Article 61 sets these rules [6]:
- Plankton: water is sampled periodically to track toxic plankton species and where they occur. Results suggesting toxins are building up in the flesh "shall be followed by intensive sampling". Plankton samples must represent the whole water column.
- Toxicity tests: periodic tests on molluscs from the part of the area most likely to be contaminated.
- Frequency: toxin analysis in molluscs "shall be weekly during harvesting periods".
- The authority may reduce this where a risk assessment shows a very low risk of toxic episodes.
- It shall increase it where weekly sampling would not be enough.
- The risk assessment must be reviewed periodically.
- Early warning: if plankton changes could lead to toxin build-up, the authority must either sample molluscs more often or close the area as a precaution until toxin results are in.
- Indicator species: where several species grow in the same area, the one that accumulates toxins fastest may be tested for the whole group. If the indicator species is over the limit, the other species may be harvested only if their own tests come back below the limits.
Approved test methods (Article 60 and Annex V): authorities "shall use" these methods, and FBOs "shall use" them where appropriate. Methods that do not use live animals must be used where possible [17].
- PSP (paralytic shellfish poisoning) toxins: AOAC OMA 2005.06 (Lawrence method), the mouse bioassay, or another validated method. Lawrence is the reference method if results are challenged.
- ASP (amnesic shellfish poisoning) toxins: HPLC/UV, with ELISA (AOAC 2006.02) allowed for screening. HPLC/UV is the reference method if results are challenged.
- Lipophilic toxins: the reference method is the EU reference laboratory's LC-MS/MS method. It must cover the okadaic acid group, pectenotoxins, yessotoxins and azaspiracids, with total toxicity calculated using EFSA toxicity equivalence factors. Other methods may be used if they meet its performance criteria.
- New or emerging toxins: chemical methods, alternative methods or the mouse bioassay may be used under national control programmes.
All of these are in [18]. The legal limits the results are judged against (PSP 800 µg/kg, ASP 20 mg/kg and so on) are in Regulation 853/2004 Annex III, Section VII, Chapter V [2].
4. Closure, reclassification and reopening
- Closure: if monitoring shows the health standards are not met, or there is another risk to health, the authority "shall close" the area. Instead, it may move the area to Class B or C if the area meets those criteria [7].
- Temporary harvesting for E. coli failures only: where only the E. coli standard is failed, harvesting may continue without closure. This is allowed only temporarily and as a one-off, based on a risk assessment. The area and the establishments receiving its molluscs must be under the same authority, the molluscs must be purified, relayed or processed, and this must be recorded on the registration document [7].
- Reopening after a biotoxin closure: this needs at least two consecutive results below the limit, taken at least 48 hours apart. The authority may also consider plankton trends. Where there are robust data on how toxicity changes in that area, plus recent data showing it falling, a single sample below the limit can be enough [8].
- Speed of decisions: the authority "shall act promptly" on closing, reclassifying or reopening an area [19].
- Industry data: FBO test results count towards these decisions only if the laboratory is designated by the authority and the sampling follows a protocol agreed with it [19].
- End-product checks: the authority also runs a laboratory control system that verifies biotoxin and contaminant levels and microbiological quality at all stages of production, processing and distribution [20].
If you give me a specific area or species, I can look at how these rules play out there.