Fisheries officers will not conduct inspections or patrols on Friday as part of a strike over pay negotiations.
Secretary of the National Union of Public Employees Janice Gemmell today announced urgent mediation had failed to avert the nationwide strike of about 75 officers planned to begin on Friday.
Fisheries officers inspect the catch of both commerical and recreational fishermen to make sure size and quota limits are adhered to.
Last week fisheries officers gave the Ministry of Primary Industries notice of the strike action which would see striking members fail to work outside the employer's premises.
"This will mean they will not conduct patrols and inspections," Gemmell said.
"MPI are failing to value the flexible role they need to protect fisheries and this industrial action is a last resort.
"MPI confirmed its position that every day has the same value and that there would be no additional payment for weekend work going forward".
A statement from the Ministry for Primary Industries (MPI) said it was "disappointed" the strike was going ahead. Around 96 of its 2600 employees were NUPE members.
The strike would mainly see fisheries officers doing only office-based work, including investigations.
"We have plans in place to manage the impact of this limited industrial action and keep our fisheries protected," MPI human resources director Erina Clayton said.
Non-union fisheries officers would carry out patrols, with honorary fishery officers and other authorised personnel picking up the slack.
"The ministry has put a very fair offer on the table," Clayton said.
"The pay and conditions for these fisheries officers have always reflected the Monday to Sunday nature of the work and this will still be the case under the new agreement."