The Ministry for Primary Industries (MPI) says zero tolerance will be given to people who fish in areas that have been closed to protect threatened marine life like Hector's dolphins.

The ministry says the warning follows the conviction of 45-year-old Christchurch man Jason Hutton, who was fined $1,000 and ordered to pay courts costs of $130 in the Christchurch District Court.

MPI spokesman Howard Reid says Hutton's offending was uncovered in late December 2018 when MPI fishery officers responded to sightings of two buoys in the Akaroa Harbour.

"Our officers were keen to see what was going on because set netting is banned in this particular area from 1 October to 31 March every year to help protect the endangered Hector's dolphins," says Mr Reid.

"The officers were able to get a close look at the buoys and establish that they were attached to a set net. They seized the net for evidential purposes. The next day, the officers saw a boat in the banned set netting area. Once the boat came to shore, the driver of the boat, Mr Hutton, admitted to the officers that he was looking for his set net.”

Mr Reid says Mr Hutton said he was unaware of the set net prohibition in the area, however, he had been inspected numerous times in the past when fishing in the area for crayfish and had received advice about recreational fishing rules in the area.

"All fishers must make an effort to be aware of the limitations for use of set nets. These rules are in place to help protect these particular dolphins. Our fishery officers are happy to help people to understand the rules and to make sure they are ready to go fishing in line with the rules.”

MPI and the Department of Conservation are currently consulting on a range of options to improve the way threats to Hector's and Māui dolphins are being managed by the Hector's and Māui Dolphin Threat Management Plan.