ASC Shrimp Traceability: Blockchain Alone Proves Nothing

More and more Vietnamese processing plants now include blockchain-based ASC shrimp traceability in their offers. Yet since 1 January 2005, EU law has required something far simpler: knowing who supplied each lot and who it was delivered to (Regulation (EC) No 178/2002, Article 18). The question came up for me while reading offers that showed a QR code and the word "blockchain" but did not attach a single lot document. The short answer: neither the ASC logo nor a digital ledger proves anything until a lot file ties them to a specific carton.

This article is for the person who writes the purchasing specification and signs the order for a container. A single restaurant does not buy a 20-foot container, so this only applies to full-container volumes. Below you will find what each type of proof establishes, what it leaves out, and the four clauses to get the plant to sign.

What does an ASC certificate prove about your shrimp lot?

The ASC (Aquaculture Stewardship Council, founded in 2010 by WWF and IDH) runs a label for responsible aquaculture. An ASC certificate shows that a specific farm has passed an audit against the standard, and that a certified plant has handled the product according to the chain of custody rules. On its own, it does not identify the container arriving at Le Havre.

For a buyer, that distinction is expensive. The logo proves a system, not a lot.

What is the difference between a farm certificate and a chain of custody certificate?

The farm certificate covers the farming stage: ponds, inputs, water management and social conditions. The chain of custody (CoC) certificate covers every business that handles the product afterwards: the processing plant, the trader and the importer. If the plant does not hold a valid CoC certificate, shrimp from a certified farm cannot carry the logo.

Every certificate carries a number and a validity date. You can check both in the public database on asc-aqua.org, which many buyers never do. Our ASC vs BAP comparison explains what each standard covers.

Why is the ASC logo not enough to trace a lot?

A plant often processes shrimp from several farms, certified or not, on the same lines. The chain of custody standard requires certified volumes to be segregated or reconciled. That reconciliation is the proof, not the logo printed on the carton. A logo without a volume balance is a claim, not evidence.

In my own Search Console data on 9 September 2026, the query "asc crevette" had an average position of 11 and zero clicks. The volume is small, but it confirms that buyers are looking for what the logo means and finding few practical answers.

What does blockchain change for ASC shrimp traceability?

A blockchain is a shared, timestamped ledger whose entries cannot be changed once written. For shrimp, it records events (harvest, receipt at the plant, freezing, shipment) that each party signs. What it really adds is timestamping and tamper-resistance after the fact. It does not make the entered data true.

The idea is not new in seafood. Provenance ran a traceability pilot on tuna in Indonesia in 2016, and IBM launched IBM Food Trust for food retail in 2018. These projects showed that the technology works. They did not solve the underlying problem.

Why does false data stay false on a blockchain?

Because the ledger does not check what gets written into it. If an operator enters "harvested at farm X on 12 March" when the shrimp actually came from somewhere else, the blockchain faithfully preserves that lie with a flawless timestamp. This is the classic input data problem: the chain guarantees integrity after entry, never before it.

A blockchain secures the archive, not the input. Only physical checks (an inspector at the farm, weighing at receipt, lab testing) bring the data closer to reality.

When does blockchain actually help the buyer?

In three specific cases. It replaces an editable Excel file with a dated history that the plant cannot quietly rewrite. It lets someone scan a QR code on the carton and trace it back to the lot. And it speeds up the response to a product recall.

None of these benefits replaces the lot file. The ledger is a container, and it is only as good as what goes into it. After an alert like the one described in contaminated shrimp: traceability makes the difference, you open the source documents, not the interface.

What proof can you audit before shipment?

Four documents can be cross-checked without any special tools: the farm's ASC certificate, the plant's chain of custody certificate, the lot file and the lot-level lab tests. Each one answers a different question. The table below compares what each one establishes, what it does not prove and how to verify it, including the blockchain ledger.

Read the table from left to right: the closer a proof is to the carton, the more useful it is. The certificate is far from the carton, while the lot file and the lab tests are close to it. The blockchain ledger is only useful if it reproduces those last two.

How can you link a carton lot code to a farm in one afternoon?

Photograph a master carton taken from the container or from the product at the plant. Note the lot code and the identification mark (the country code followed by the establishment's approval number on the European Union list). Ask for the matching harvest record: farm, pond and date.

Then check three things. Is the farm's number in the ASC database? Was the certificate valid on the harvest date? Does the volume bought from that farm cover the tonnage sold under the logo? Our supplier verification checklist places this test right after the plant visit.

On arrival, the SIVEP border check at Le Havre or Antwerp cross-checks the official health certificate and takes samples. The process is described in what happens to your container at Le Havre. A consistent lot file saves you from discovering a discrepancy once the container is already on the quay.

What to write in your specification for verifiable ASC traceability

The specification turns a sales promise into a documentary obligation. The four clauses below are the ones we get the plant to sign before opening an order, for a container shipped FOB Ho Chi Minh City.

Which clauses should you require from the supplier, with figures?

1. Certificates. A dated copy of the farm's ASC certificate (valid on the harvest date) and of the plant's CoC certificate, with their numbers, sent no later than 5 working days before shipment.
2. Lot file. For each lot code printed on the master cartons: farm, pond, harvest date, receipt date, production date and origin of the post-larvae. The file is supplied before shipment and kept by the plant for 24 months.
3. Volume reconciliation. A balance in kilos: certified volume bought from the farm, volume processed and volume shipped under the logo. The volume shipped must never exceed the certified volume bought.
4. Lot-level lab tests. An antibiotic residue report issued by a laboratory accredited to ISO/IEC 17025 and linked to the lot code. The residue control plan lists the molecules to target.

Payment is where you enforce this. With a 20% deposit and the remaining 80% by CAD (cash against documents), add the lot file and the CoC certificate to the list of documents required to release the balance. A plant that objects to this clause is telling you what it cannot prove. For the full timeline, see ordering a container of shrimp from Vietnam.

Want to price these clauses for your sizes? Request an FOB quote by size within 48 hours, based on this specification, and state that you require the lot file.

How much does a blockchain option add per delivered kilo?

I have no reliable public price to quote. Providers charge by subscription or by volume, and plants may or may not pass the cost on. So the calculation has to be done on your own quote. Purely as an illustration, a surcharge of €0.01/kg on 10,000 kg comes to €100 per container, which is negligible against the delivered cost but not free.

The real question lies elsewhere: who enters the data, who checks it and who pays for the audit. Ask for the surcharge as a separate line, so you can drop it without touching the product price. If the supplier offers a ledger, add a clause requiring a raw export of the records on request, with the identity of the entity that entered each data point.

Verdict: should you require blockchain for your ASC shrimp?

No. Require the lot file, the volume reconciliation and the lab tests, then treat blockchain as a nice-to-have. Approve without conditions: a plant that supplies all four documents before shipment. Test on a single container: a supplier whose blockchain is included but whose lot file is missing. Avoid: a supplier who offers a QR code in response to your request for documents.

My position is firm because it rests on how the mechanism works, not on fashion. An unalterable ledger does not correct a wrong entry, and the entry is exactly what your specification can control.

When is it worth testing the blockchain option?

When your annual volume justifies several containers from the same supplier, when a retailer further down your chain requires a searchable history, or when you want to shorten product recalls. In all three cases, test it on a single container and compare the ledger data with the paper lot file. If the two diverge, you know where the error lies before volumes increase.

For reference figures on the market and labelling rules, the European Commission publishes the requirements of Regulation (EU) No 1379/2013 (commercial designation, production method, country of farming) on oceans-and-fisheries.ec.europa.eu. The EUMOFA observatory publishes market data for seafood products.