The Status of New Zealand’s Fisheries report for 2016 released this week shows a record percentage of the tonnage and value of landings of scientifically evaluated stocks have no sustainability issues.
Highlights from recent assessments indicate strong performance for:
*all stocks of hoki
*most stocks of rock lobster
*most stocks of gurnard
*four stocks of rig
*three stocks of orange roughy
*two stocks each of blue cod, scampi and barracoota
*snapper in Tasman and Golden bays
A total of 160 stocks were evaluated, with 133 showing no sustainability issues.
Ninety seven percent of scientifically evaluated landings were from stocks above or well above sustainable levels.
Of the remaining 27 stocks, corrective management action is in place for all of them to enable rebuilding.
So how do we know this?
Each year MPI convenes a large number of Fisheries Assessment Working Group meetings that are open to anyone who wants to attend.
Those meetings evaluate evidence from scientific researchers, catch and effort reports from commercial fisheries, data from on-board observers and other relevant information to produce assessments of the status of New Zealand’s fish stocks.
That information is summarised in two annual plenary reports, a massive 2000-page document comprising five volumes.
That information, too, is public.
There are currently 98 species divided into 642 fish stocks in the Quota Management System. Nearly half – 292 – are considered to be nominal stocks, leaving 350 that are in the QMS. Fish stocks fluctuate due to a number of environmental factors that include water temperature, available feed, breeding conditions, and predation as well as fishing. While the numbers cannot be absolutely defined, well informed estimates of stock size, as well as their levels of uncertainty, are presented.
Four performance measures are used to guide the management of each stock, consistent with the Fisheries Act 1996, the 2008 Harvest Strategy Standard and various fisheries plans.
This is where it gets complicated but the essence is the measures are a soft limit (a biomass level below which a stock is deemed to be overfished or depleted and needs to be rebuilt); the hard limit (a biomass level below which a stock is deemed to be collapsed and closures may be required); the overfishing threshold (a rate of extraction that should not be exceeded); and the management target (a biomass level or mortality rate that stocks are expected to fluctuate around).
Like Forest & Bird, MPI uses colour coding to rate stock status but its green, yellow, orange and red palate is scientifically based rather than emotionally driven and is therefore a good deal more accurate and reliable.
Where stocks are deemed to be overfished, in all cases corrective action is in place.
This includes closure of the Tasman and Golden bay scallop fisheries, bluenose catch reductions, closure of two orange roughy stocks, and bluefin and bigeye tuna rebuilding in the Pacific.
Hoki quotas were substantially reduced from 2001-07 and as a result both major stocks to the east and west of New Zealand have increased in size for the last consecutive eight years.
The stocks are currently at their highest levels this century.
Overall, this latest stock status report is good news, confirming this country is at the forefront of fisheries management, and will no doubt be hailed as such by recreational fishing and environmental lobby groups as well as the commercial sector.