Commercial rock lobster catch quotas for Otago and Southland will decrease by up to 8% this week.
Fisheries and Aquaculture Minister Phil Heatley announced the changes on Monday and they will apply from Friday.
In Otago (CRA7), the total catch limit will decrease by 8%, from 104.5 tonnes to 95.7 tonnes.
The decrease was decided on because of "large fluctuations in lobster numbers", Mr Heatley said.
"The catch-limit reduction is likely to quickly assist the stock to a stable situation that provides greater and consistent benefits for all fishery participants."
In Southland (CRA8), the total catch limit will decrease by 5%, from 1110 tonnes to 1053 tonnes, because of the "conservative" management regime, rather than sustainability concerns.
In both areas, the reduction will apply to commercial catches only and non-commercial allowances will be unaffected.
Otago rock lobster fishery CRA7 executive officer Simon Gilmour was "quite happy" with the decrease, as it was "basically what we caught last season".
He expected the fishery to rebuild over the next three years, thanks to recent recruitment.
Scientific and management information, as well as submissions from the public and customary, recreational and commercial fishers were used to reach the decisions.
"The Government wants to facilitate a responsive management regime that helps ensure sustainability and provides for appropriate levels of use of the highly valuable rock lobster fishery," Mr Heatley said.
Catch limits in the Wellington and Hawkes Bay spiny rock lobster fishery will increase 8%, from 610.625 to 661.9 tonnes for commercial fishers only.
No changes were proposed in the Canterbury and Marlborough spiny rock lobster fishery.
Penalties for fishing over the limit will increase for all spiny and packhorse rock lobster stocks.
The annual deemed value rate will increase from $100 to $110 a kilogram; the interim deemed value rate will increase from $75 to $99 a kilogram; and the differential deemed value rates will be adjusted accordingly.
