An 11.8-tonne reduction in the amount of rock lobster able to be caught this season is estimated to cost the Otago commercial fishery about $660,800.
With the rock lobster fishing season to begin tomorrow, the Ministry of Fisheries has announced decreasing Otago's total catch limit from 95.7 tonnes to 83.9 tonnes.
Ministry fisheries management director James Stevenson-Wallace said the catch changes were based on the best available scientific and management information, as well as submissions from customary, recreational and commercial fishers and the public.
"Rock lobster fisheries are closely managed to ensure long-term sustainability, as well as securing benefits for all fishery sectors."
The industry group representing Otago rock lobster fishery CRA7 supported the reduction and was committed to building a sustainable fishery, he said.
The Rock Lobster Management Group final advice paper said CRA7's stock size had shown a 56% decline in 2009, then recovered slightly before decreasing 31% in 2011.
The report estimated the decrease had the potential to reduce earnings of the commercial fishers by about $660,800.
CRA7 executive officer Simon Gilmour said the group supported the reduction because the fishery was in a rebuilding phase.
"There is a large number of small lobsters that will grow up and the fishery will come back in two to three years."
That was the downside of a migratory fishery, that every few years a rebuilding period was needed, he said.
It would mean a shorter season for the 12-14 boats that crayfished each year, but the financial effect was not as great as it could be, because the boats also fished for other species, Mr Gilmour said.
"All those involved here fish for other species."
Customary and recreational takes were not affected and remained the same.
