A Whangarei father and son have been fined almost $4,000 after being caught running an illegal black-market crayfish operation from their home.

David Vance Gavin, 48, and his son, Levi Rama Gavin, aged 28, were fined a total of $3,800 plus courts costs totalling $260 when they appeared in the Whangarei District Court for sentencing. A cellphone used in the pair's offending was also forfeited to the Crown.

Ministry for Primary Industries spokesman Steve Rudsdale said the pair was involved in catching and selling crayfish mainly from the Whananaki area on at least nine occasions between July and October 2015, selling around 20 crays.

"The crayfish were generally sold for $20 each for a 'just legal' sized crayfish, $30 for a reasonably sized one and $40 for a large one. Sometimes that price varied for bulk buyers and for close friends," Rudsdale said.


"There were multiple occasions over several months in 2015 where they arranged delivery and payment of crayfish, including for raffles," he said.

"When we questioned them on numerous occasions about their activities, they denied they were selling the crayfish. On one occasion, they claimed the crayfish were for a wedding, then said they were for a 50th birthday party. Obviously, this sort of offending is very disappointing."

Rudsdale said there are very good reasons why catch limits exist for New Zealand's various fish species, particularly high-value species like crayfish.

"New Zealanders need to respect this. We all have a responsibility to ensure our fishery is protected and remains sustainable for current and future generations," he said.

The sale of seafood taken recreationally is an offence under the Fisheries Act, and buyers are equally liable as sellers, with a maximum fine of up to $250,000 and confiscation of any gear used.