Ministry of Primary Industries Fishery officers caught two recreational fishers with over five times the limit of kahawai on Saturday.
The daily bag limit for kahawai is 20 per person. The pair were caught with 211.
Someone tipped MPI off on the breach at Karioitahi Beach, Port Waikato. The fishers' catch was inspected in Auckland.
MPI Regional Manager Fisheries Compliance Phil Tasker said: "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,"