This is outlined in a Fisheries Assessment Plenary report, published on the internet. These annual reports, providing scientific information about fish populations and the impacts of fishing, are a key tool for managing fisheries.
"The reports are publicly available, so anyone can see what the science is showing about New Zealand's fish stocks," says MPI's principal fisheries science advisor Pamela Mace.
Dr Mace says the highlights in the report released this week include a new and substantial group of orange roughy on the Chatham Rise. "This has led to an upward revision of the status of this stock."
All stocks in New Zealand's Quota Management System are managed for long-term sustainability. If a fish stock is found to be declining, MPI fisheries managers may propose a change, for example reducing the catch limit.
The first part of the 2012 Fisheries Assessment Plenary, the May report, summarises fishery, biological, stock assessment and stock status information for 82 of New Zealand's commercial fish species or species groups.
A further report in November covers another 18 species, including highly migratory species.
The Plenary reports are based on science work commissioned by MPI.
MPI and its predecessors have been producing these reports for 28 years, Dr Mace says. "We have been striving to continually improve the information content and utility of the reports. For example this year a system ranking the quality of scientific information has been included for the first time."
Other key findings in the May Report are:
- Both stocks of hoki (eastern and western) have continued to increase in size over the past six consecutive years, and both are now well within their target range.
Southern blue whiting on the Campbell Island Rise is estimated to be well above its management target and is currently at an historic high.
Gurnard around the east and south coasts of the South Island was assessed to be very likely to be above its management target, and on the west coast of the South Island the trawl survey estimate for 2011 was the highest recorded since 1992.
The trawl survey estimate for John dory off the west coast of the South Island was also the highest recorded since 1992.
- Elephantfish populations around the east coast of the South Island appear to have fully rebuilt, and around the south coast of the South Island they have been continually increasing since the mid-1990s.
"There appears to have been a general increase over the past 1020 years for the snapper stock on the northeast coast of the North Island, but preliminary results this year indicate that further rebuilding is still needed," says Pamela Mace. "MPI is commissioning some further scientific investigation of this."
Also, the paua stock on the north coast of the South Island has been assessed as being in need of rebuilding, Dr Mace says.
MPI fisheries managers are now considering the status assessments and whether there is a case for proposing changes to management of some stocks.