Four fishers are facing prosecution after they were caught with large, illegal hauls of seafood.
The Ministry of Primary Industries (MPI) said it was tipped off by a member of the public who helped them catch two fishers with 211 kahawai on Saturday after they'd been fishing at Karioitahi Beach, Port Waikato.
The daily bag limit for kahawai is 20 per person and the people involved had more than five times the limit each.
"The public are our eyes and ears and MPI is grateful to the person who provided solid information that led to us stopping these people and inspecting their catch when they returned to Auckland," MPI regional manager fisheries compliance Phil Tasker said.
"The rules are there for a reason - to protect fishing resources to ensure there are enough fish in the water for generations to come."
In a separate incident on Sunday, MPI, with the help of Auckland Police maritime unit, caught two men fishing in the Hauraki Gulf with a haul of 117 undersize pāua, seven undersize snapper and one undersize packhorse lobster.
"This was a lot of undersize fish, threatening the sustainability of our shared fishing resources," Tasker said.
All of the fishers involved in these incidents are likely to face prosecution as MPI considers this "serious fisheries offending".
One of the men involved who MPI considered a "recidivist fisheries offender" was also arrested by police for breach of his bail conditions.
