The improving state of our fisheries
Tuesday 11 August 2015
Each year the Ministry convenes a large number of Fisheries Assessment Working Group meetings, open to anyone who wants to attend. Presentations are made by researchers at these meetings, combining the results of scientific research with catch and effort reports from commercial fisheries, data from the on-board observer programme and other information sources. Detailed summaries are provided in a five-volume annual Fisheries Assessment Plenary report. Information on stock status is then further summarised and published by MPI as The Status of New Zealand's Fisheries. The report measures the status of New Zealand's fish stocks against the Harvest Strategy Standard (HSS) for New Zealand Fisheries (2008) - a standard aligned to the Fisheries Act. The HSS specifies four performance measures: the soft limit - a biomass (the total weight, in tonnes, of a particular species of fish in a defined area) level below which a stock is deemed to be "overfished" or depleted and needs to be actively rebuilt;
the hard limit - a biomass level below which a stock is deemed to be "collapsed", where fishery closures should be considered in order to rebuild a stock at the fastest possible rate;
the overfishing threshold - a rate of extraction (percentage of a stock removed each year) that should not be exceeded as it will ultimately lead to the stock biomass declining below management targets and/or biomass limits, if this hasn't already happened;
and the management target - usually a biomass level, but sometimes a fishing mortality rate, that stocks are expected to fluctuate around, with at least a 50 per cent probability of achieving the target. By the end of 2014, 83.6 per cent of our fish stocks of known status were above the "soft limit", 94.3 per cent were above the hard limit, 86.0 per cent were below the overfishing threshold, and 72.3 per cent were above their management targets. When considering the tonnage of landings of fish stocks of known status in 2014, 96.4 per cent of the landings was made up of stocks above the 'soft limit', 99.5 per cent was of stocks above the 'hard limit', 95.9 per cent was of stocks below the 'overfishing threshold', and 90.3 per cent was of stocks above their management targets.
HIGHLIGHTS FROM THE 2014 AND 2015 PLENARY REPORTS
As a consequence of substantial reductions in hoki quotas over the period 2001-2007, both stocks of hoki (eastern and western) increased in size for eight consecutive years, and have subsequently stabilised in 2015 at a level above the upper end of the management target range. As a result, the hoki TACC has been progressively increased from 90,000 metric tonnes to 160,000 metric tonnes over the period 2008-2014.
Four new stock assessments for orange roughy were completed in 2014, with three of the stocks - two on the Chatham Rise and one on the Challenger Plateau - showing moderate to substantial increases in biomass from the late 1980s to early 2000s, with the current biomass being near or within the management target range in all three cases. The fourth assessed orange roughy stock - on the mid-east coasts of the North and South Islands - appears to be rebuilding slowly but is below the management target. A TACC reduction for this stock was implemented in 2014.
The Campbell Island Rise southern blue whiting stock is estimated to be well above its management target and is currently near historically high levels.
An international assessment of yellowfin tuna in 2014 showed that it is performing well relative to all harvest strategy standard performance measures.
New assessments for almost all rock lobster stocks show that all are performing well relative to all harvest strategy standard performance measures. Rock lobsters in the Bay of Plenty are an exception as they are estimated to be below their management target (but well above biomass limits). The Chatham Rise rock lobster stock has not been assessed.
New assessments for three paua stocks along the east, south and southwest coasts of the South Island (areas PAU 3, PAU 5A and PAU 5B) show that all of these stocks are at or above their management targets.
New stock assessments in 2013-2015 show that red gurnard are at or above their management targets in virtually all areas where they occur (although overfishing may be occurring in some South Island areas).
Tarakihi on the west coast of the South Island were assessed to be performing well in 2014 relative to their management targets and biomass limits.
The biomass of stargazer (monkfish) on the west coast of the South Island has increased strongly over the period 2008-15 and was assessed to be performing well relative to all harvest strategy standard performance measures in 2015.
The biomass of snapper along the north and west coasts of the South Island was assessed in 2015 to have increased substantially from 2010 to 2014.
Trevally on the west coasts of both the North and South Islands was assessed in 2015 to be above the management target with overfishing very unlikely to be occurring.
Elephantfish around the east and south coasts of the South Island appear to have substantially rebuilt from the low levels experienced in the late 1980s.
RESPONSES TO STOCKS BELOW BIOMASS LIMITS
In all cases where stocks are below the soft or hard limit, measures have been, or are being, put in place to rebuild the stocks. For example, fisheries on two orange roughy stocks or sub-stocks have been closed (they effectively have a TACC total allowable commercial catch) or voluntary catch limit of zero) to maximise the rate of rebuilding.
A rebuilding plan was implemented for the orange roughy stock on the mideast coasts of the North and South Islands in 2014. The Tasman Bay scallop fishery has been voluntarily closed to all commercial fishing since 2006, and the Golden Bay scallop commercial fishery has been voluntarily closed since 2011. Bluenose stocks were identified in May 2008 as needing rebuilding. Three TACC reductions were implemented in 2008, 2011 and 2012 to ensure the stocks rebuild to target levels.
The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) has adopted a management procedure designed to rebuild the stock to interim and long-term target levels. Conservation measures have also been adopted for bigeye tuna by the Western and Central Pacific Fisheries Commission (WCPFC).
New Zealand is an active member of both of these Commissions. These changes demonstrate the responsiveness of New Zealand's fisheries management system to the intrinsic fluctuating nature of wild fish stocks and our contributions to the management of international fish stocks.
Friday 17 August 2018
The Chatham Islands paua fishery is leading the way in local fisheries management.
Friday 10 August 2018
The Tasman Sea is warming at one of the fastest rates on Earth, four times the global average.
Friday 3 August 2018
Cameras will not be introduced on commercial fishing vessels before other pressing issues are addressed, Fisheries Minister Stuart Nash confirmed yesterday.