Contrary to the views of critics, New Zealand fish stocks are not in decline, writes Pamela Mace.
OPINION: In A recent Dominion Post column (Marine reserves too small to serve their purpose, March 26), Jay Harkness, of Forest & Bird, claims "the overall number of fish in New Zealand waters is in steep decline".
Nothing could be further from the truth. For example, our largest fishery, hoki, is thriving. Both the eastern and western stocks of hoki have shown six consecutive years of increasing abundance and are approaching the upper end of the target range that fisheries managers aim to keep the stocks within. As a result, since 2009, the quota for hoki has been progressively increased from 90,000 metric tonnes to 130,000 metric tonnes.
New information being analysed shows that both hoki stocks are continuing to grow even under the increased catch levels. (Most fish species are divided into several stocks, based on geographic areas for fisheries research and management purposes.)
It's not only hoki stocks that are doing well. Orange-roughy stocks have also been increasing. Several have rebuilt and two have been reopened after several years of closure.
In 2011, a new and substantial aggregation of orange roughy was discovered on the Chatham Rise. Southern blue whiting off Campbell Island is at a historic high. Research survey estimates for both gurnard and john dory off the West Coast in 2011 were the highest recorded over the period 1992-2011.
Elephantfish around the east coast of the South Island appear to have fully rebuilt and elephantfish around the south coast of the South Island have been increasing since the mid-1990s.
However, not all stocks are in an increasing phase. Fish stocks fluctuate naturally even in the absence of fishing. The status of these fish stocks is determined through a rigorous, transparent science working-group process with open participation by technical experts, stakeholders and any other interested parties, including environmental organisations.
Of the stocks of known status in 2012, 83.2 per cent were described as not overfished. These represented 96.6 per cent by weight of the fish brought to shore.
For stocks considered to be overfished, corrective management action has been or is being put in place to rebuild them.
For example, bluenose stocks were identified as being in need of rebuilding in May 2008, and quotas were subsequently reduced later in 2008, with further reductions in 2012.
To ensure transparency, the Ministry for Primary Industries has made all of this information available on its website for several years in both detailed and summary form.
In summary, New Zealanders can be assured that their fisheries as a whole are performing well, that the ministry is taking corrective action for the relatively few fish stocks where this is not the case and that a substantial proportion of our waters are protected from any potential adverse effects of fishing.
Dr Pamela Mace is the principal adviser for fisheries science at the Ministry for Primary Industries. Her career as a fisheries scientist spans more than 30 years, both in New Zealand and overseas.
- The Dominion Post
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