The Fisheries Ministry says a man charged with gathering excess and undersized paua from a marine reserve can not use the excuse he was sorting which shellfish to take.
Russell Gibbs is on trial for taking 39 paua, including 19 smaller than the legal limit, from the prohibited Parininihi Marine Reserve north of New Plymouth.
The judge reserved his decision on Monday.
Mr Gibbs told the court that he and three children as young as five years old had collected paua for a hui and were sorting them to meet recreational limits when fisheries officers arrived.
However, a prosecutor for the ministry told the New Plymouth District Court that is not allowed.
Katy Martley said courts have ruled against what is known as high-grading - catching extra fish to keep the best ones.
Ms Martley says paua size can be assessed on the rock or when it is removed and undersized shellfish can be returned immediately.
Mr Gibbs told the court that the paua were being sorted in a traditional, practical and reasonable method.
Mr Gibbs said that he and the children were choosing their limit of 10 each from a collective pile on the reef so the children could not take too many or too small paua.
He told the court the children were learning how to look after visitors, the environment and their iwi, and the extra shellfish were to be returned immediately.
A chief of the Poutama iwi told the court on Monday that he asked his people to gather food for the hui.
Haumoana White said he is ashamed that the iwi can not put seafood on the table for visitors and disappointed that children had to witness fisheries officers confiscating paua gathered according to centuries-old practice.
Minister cited in defence
In court, Russel Gibbs cited former Fisheries Minister Jim Anderton in his defence and claimed that fisheries officers allowed his group to take other shellfish and an octopus from the reserve when they confiscated the paua.
Mr Gibbs said that he and the children were collecting food under recreational rules because fisheries officials had kept a customary permit book locked away from the Poutama iwi.
He argued the marine reserve was improperly established and therefore void and has lodged documents to build his case.
These included a letter from Mr Anderton stating that the Parininihi Marine Reserve was not intended to extinguish any customary rights.
Prosecutors sought to restrict the defendant's argument, saying the reserve was legal on the day of the incident.
