MSC Chain of CustodyMarine Stewardship Council Chain of Custody

MSC operates two distinct standards. The Fisheries Standard is assessed against a fishery — its stock status, ecosystem impact and management system — by an accredited certification body. The Chain of Custody (CoC) Standard is assessed against every business along the supply chain that takes ownership of certified product: processors, distributors, packers, traders, and in some cases retailers and food-service operators.

The MSC blue label on a finished product requires both halves: a certified fishery at the origin and an unbroken CoC chain through every link to the labelled SKU. Break the CoC chain at any link and the product loses the right to the label.

The Fisheries Standard assesses three principles: sustainable fish stocks (stock status, recovery if needed), minimising environmental impact (bycatch, habitat, ecosystem), and effective management (governance, compliance, monitoring). Certification is delivered by accredited third-party assessors against a published evidence framework, with full public consultation during assessment.

Fisheries are recertified on a five-year cycle with annual surveillance audits. Conditions imposed during certification are tracked and must be closed within agreed timeframes; failure to close conditions can suspend certification.

The CoC Standard applies to every business that takes ownership of MSC-certified product where the certified status is to be carried through. Five core requirements run through the standard:

• Certified product is purchased only from certified suppliers.
• Certified product is identifiable through every step.
• Certified and non-certified product is segregated.
• Certified product is traceable and volumes are recorded for mass-balance reconciliation.
• The CoC management system is audited annually with sites selected on a sampling basis for multi-site operations.

For UK food manufacturers handling wild-catch seafood, CoC certification is the operational requirement. A manufacturer must hold its own CoC certificate covering the sites that take ownership of MSC product, must verify supplier CoC certificates at goods-in, and must run mass balance per certified species/product per period.

The most common failure mode at manufacturer level is mass-balance reconciliation between certified material in and certified product out. Mixed-stream lines (certified and non-certified product on the same line) need segregation and identification evidence that lands cleanly during the annual CoC audit.

Every major UK retailer — Tesco, Sainsbury's, M&S, Waitrose, Morrisons, Asda, Aldi, Lidl, Co-op — requires MSC certification for sustainable wild-catch claims on own-brand seafood. Many retailers have specific commitments around what proportion of their wild-catch range is MSC, and category technologists track movement against those commitments.

• Operating without a manufacturer CoC certificate and assuming the supplier's certificate is sufficient.
• Mixing certified and non-certified product on the same line without documented segregation.
• Letting the annual CoC audit slip past the renewal window.
• Buying certified material from a supplier whose own CoC has lapsed.
• Mass-balance variance exceeding tolerance without a documented investigation.