Company unlawfully moved 250,000kg of mussels from ‘infected’ zone to global supplier

Wednesday, 14 January 2026

A South Island company moved hundreds of tonnes of mussels from an infected area to an international supplier, risking the outbreak of a “decimating” disease with no proven method of eradication.

Green lipped mussel farmer Aroma Aquaculture was paid $500,000 to move its product to a Christchurch factory during 2024, but it never followed regulations established to manage an oyster-killing parasite that mussels can transmit.

The company pleaded guilty to a representative breach of the Biosecurity Act in the Christchurch District Court on Wednesday morning, and could be fined up to $100,000 at a sentencing scheduled for March.

Aroma Aquaculture operates in the Marlborough Sounds and Canterbury, farming and harvesting green lipped mussels for its sister company Aroma (NZ) and other suppliers, according to a summary of facts.

The company directors are father and son Bernardus Gerhard Winters and Benjamin Simpson Winters.

In a statement, Aroma Aquaculture said: “The matter is currently before the court and therefore we have no comment at this stage.”

On October 9, 2024, a biosecurity inspector became aware that international mussel supplier Ikana New Zealand had received live mussels at its Christchurch-based factory from Aroma Aquaculture farms in the upper South Island.

The Ministry for Primary industries has designated large parts of the upper south a ‘contained zone’ known to be “infected” with the flat oyster-killing parasite Bonamia Ostraea. Moving mussels from a contained zone to an ‘unaffected zone’, like Christchurch, requires a permit and strict treatment measures.

However, neither Aroma Aquaculture or Ikana held a relevant permit - prompting an examination of the Christchurch factory and Ikana’s historic mussel consignments.

The inspection revealed Aroma Aquaculture had moved about 250,000kg of mussels from the contained zone to Ikana’s factory across 27 shipments during 2024. On 16 occasions Aroma Aquaculture had provided an irrelevant permit to its transporter, but it never held the correct one.

“In total, the defendant company received $518,840 for the 27 movements,” the summary said. “A permit for these movements could have been sought by any one of the three parties involved. There is no cost for applying for a permit.”

Ikana had since obtained a permit for the relevant movement of green lipped mussels, which imposed strict biosecurity protocols on it, the supplier and Aroma Aquaculture.

“The defendant company held no records of evidence of having previously been adhering to these biosecurity operating protocols prior to this time.”

The summary said Bonamia Ostreae outbreaks have “severely damaged and in some instances entirely decimated oyster fishery areas” and “there are no proven methods for eradicaton” once the disease is established. Flat oysters are valued by iwi in both the upper and lower South Island.

Furthermore, by arranging the movement of mussels from a contained zone to Ikana, which exports all its product overseas, including to Asia and the USA, Aroma Aquaculture had risked impeding the green lipped mussel economy.

Industry export earnings were valued at $390 millon in 2023 and it was aiming for export value expansion to $1 billion by 2035. However, exports relied heavily on reputation and New Zealand’s “clean green” image, the summary said.