Investigations are continuing after four people were found with a total of 736 paua in the Taranaki last week, most of them undersized.
Traditionally large numbers of people have taken excessive amounts of shellfish, particularly paua, during this time of year on low tides.
In a joint operation on State Highway 45 near Okato, police and the Ministry of Primary Industries stopped and inspected cars over two days last week.
The checkpoint ran over two days and resulted in one set net being seized and a number of people given infringements and fines totalling $1750.
MPI spokesman Jason Howat said the south Taranaki coastline is a high-risk area of offending and said the discovery of hundreds of undersized paua was "staggering".