New catch limits in Fiordland from 25 April mean recreational fishers will be only able to take smaller bags of finfish and shellfish.
The rule changes are in response to fish stock pressures of popular species in the area, including rāwaru/-lue cod, hāpuku-groper, pāua and scallops.
Government-appointed Fiordland Marine Guardians said new recreational fishing rules would address pressure on stock levels in the area.
A particular focus for the Guardians was to reduce fishing in the vulnerable inner fiords and also the entrances to them, where stocks appear depleted.
Fiordland Marine Guardians chair Rebecca McLeod told RNZ's Nine to Noon that reducing the overall level of fishing pressure ensured stocks could be rebuilt.
"We need the fishers out there to act responsibly and to follow the rules because they are invested in the future of Fiordland and the mission that the Guardians are on."
Fishers are being encouraged to move to the outer waters.
"They were able to take a bag limit of 30 finfish throughout Fiordland, and now we're reducing that to a total of 20 if you're on that open coast, and if you're inside the fiords, 10," McLeod said.
The daily limit for blue cod on the open coast is 10, and inside the fiords is one.
For pāua, the daily limit on the open coast is five, and inside the fiords is two.
The changes also include the closure of scallop and oyster fisheries throughout the Fiordland Marine Area, and of hāpuku/groper/bass fishing in the innermost parts of all fiords.
No changes have been made to rock lobster limits.
"Fiordland is a unique and treasured part of New Zealand and is home to many fish species. I want to keep it that way," Oceans and Fisheries Minister Shane Jones said.
"As well as catch limits being reduced for species such as blue cod, hāpuku/bass and pāua, the boundary line for lower daily limits for some species has been moved further out to shift fishing to more productive areas."
In the Chatham Islands, there will also be reduced recreational catch limits for most fish species from Thursday.
"The Chatham Islands are known for being rich in kaimoana, attracting fishers seeking some of New Zealand's most sought-after fish species," Jones said.
Also coming into effect on 25 April is the catch limit for quinnat salmon caught from the ocean - it will reduce to one fish per person per day, nationwide.
It was in line with the limit for rivers and freshwater, Jones said.
Jones said decisions were made based on local concerns.
"What's clear is that we all want our fisheries to be healthy and sustainable so they continue to provide now and in the future," Jones said.