11_BNS_09

Filename
11_BNS_09.pdf

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11_BNS_09.pdf (468.2 kb)

Abstract
CPUE has previously not been considered to be a reliable indicator of abundance of BNS stocks. However, close coincidence observed in declining trends in most CPUE indices in recent years has increased confidence in their value as indices. Standardised CPUE series, based on data from six fisheries which span most of major fisheries taking BNS in the NZ EEZ, have declined an average of 64% over the period 2001–02 to 2006–07 (Table 3).

If this decline is indicative of the overall abundance of bluenose in these areas, then BNS abundance could have declined by more than 50% across all areas over these six years. If there has been replenishment of the features being fished in the period prior to the decline, the overall decline in abundance could be even larger. Although factors other than abundance may have contributed to the declines in CPUE and catches, current BNS catches and TACCs do not appear to be sustainable.

There is currently no stock assessment available for any BNS stock to allow estimation of BMSY and BCURR. Further, uncertainty regarding the extent of the stock which is contributing to the bluenose fisheries in the various QMAs makes it difficult to estimate BMSY for these stocks. The current status of the bluenose populations in each of the BNS QMAs relative to BMSY is unknown.

The concurrent decline of six independent CPUE series covering all the main NZ EEZ bluenose fisheries may indicate that there is a single New Zealand stock of bluenose. The Plenary noted that declines in CPUE have been observed even in areas that are relatively lightly fished such as BNS 7 and BNS 8. The existence of a single NZ-wide bluenose stock declining in all areas would imply not only that current catches are unsustainable, but that the overall combined TACC is also unsustainable.

Document date
Sunday, 31 May 2009

Document type
V 1.3

File format
Adobe PDF

File size
468.2 kb

Reference number
2009

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M:\SCIPOL\Working Groups 2009\Plenary 2009\FINAL\MFish 2009 May Plenary\May 2009 - PDF\11_BNS_09.pdf

Uploaded date
Wednesday, 10 June 2009

Search tags

Species: BNS;
Stock: BNS1; BNS2; BNS3; BNS7; BNS8;

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