96_STA_09

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96_STA_09.pdf

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96_STA_09.pdf (384.0 kb)

Abstract
No estimates of current and reference biomass are available.
STA 1
The TACC for STA 1 was increased from 21 t to 50 t in the 1991–92 fishing year under the AMP. In 1997, the TACC was reduced to 21 t upon its removal from the programme. Recent catches have exceeded this level. It is not known if recent catch levels and current TACC are sustainable. Thestatus of STA 1 relative to BMSY is unknown.

STA 2
The TACC for STA 2 was increased from 37 t to 100 t in the 1991–92 fishing year under the AMP. Landings in the early 1990s peaked in the range of 105–125 t, but have subsequently declined. Recent relative abundance indices from both the ECNI inshore trawl survey and the ECNI scampi trawl survey are lower than those in 1993. The 1997 assessment suggested that the exploitation rate was very high, but the model results were determined by the choice of maximum allowable exploitation rate. An upper bound of 80% for the catch/biomass ratio was used in the base case, but this wasconsidered unrealistically high.

The TACC was reduced back to 38 t in the 1997–98 fishing year, upon the removal of STA 2 from the programme. Landings have been slightly above the TACC in recent years. It is not known whether recent catches and the current TACC are sustainable. The status of STA 2 relative to BMSY is unknown.

STA 3
STA 3 is being managed within an AMP. Based on the reinstated winter ECSI trawl survey and an overall review of a range of available information pertaining to stock status. The TACC for STA 3 was increased from 734 t to 900 t in the 1991–92 fishing year under the AMP.

The reinstated ECSI trawl survey returned a biomass estimate that was slightly above the 5 indices observed in the early 1990s. This biomass estimate was also consistent with the CPUE series developed for the bottom trawl fishery targeted at red cod, stargazer and barracouta within the context of the STA 3 AMP. On this basis, the Working Group concluded that current catches have been sustainable over the 18 years of the CPUE series, although it is not known if the TACC is sustainable, given that the average catches over this period have been about 15% below the TACC. Relative biomass indices for stargazer from the annual trawl survey of the western end of the Chatham Rise have remained stable. It is not known if recent catch levels and the current TACC are sustainable inthe long-term. The status of STA 3 relative to BMSY is unknown.

STA 4
Stargazer in this Fishstock occur mainly on the Chatham Rise and on the shelf around the Chatham Islands, but are sparsely distributed over the rest of the Rise. In most of this Fishstock they may not be economical to target. However, if fishing is overly concentrated in those areas where stargazer can be targeted, such as close to the Chatham Islands, there are concerns that local depletion may occur.

The current TACC of 2014 t for STA 4 was based on a yield estimate from a single trawl survey in 1983. This method is now considered obsolete. Recent catches have been substantially less than the TACC; the stock appears to have been lightly fished and is still likely to be in the fishing down phase. It is not known if catches at the level of the current TACC would be sustainable. The status of STA 4 relative to BMSY is unknown.

STA 5
The TACC for STA 5 was increased from 1239 t to 1500 t in the 1991 92 fishing year under the AMP. Landings increased to 1327 t in 1993–94, declined to 544 t in 1997–98, but have subsequently increased. The TACC was reduced to 1264 t in 1997, upon the removal of STA 5 from the AMP. This new TAC is at the level of recent catches, and is probably sustainable. The status of STA 5 relative to BMSY is unknown.

STA 7
The TACC for STA 7 was increased from 700 t to 997 t from 1st October 2002. STA 7 is being managed within an AMP based on the WCSI trawl survey and an overall review of all available information, including commercial catch data, and supplemented by a preliminary quantitative stock assessment. The WCSI trawl survey indices have increased from a low observed in 2003 to the highest in the series in 2009 (preliminary estimate). The results of the quantitative stock assessment suggested that stock biomass during the 2004–05 fishing year was unlikely to be below the biomass required to support the maximum sustainable yield. . The range of model results for STA 7 west coast stock assessment suggests that, given the assumptions about recruitment, the stock size on average should increase under current catch levels and suggests that the stock size is Likely to be above BMSY.

STA 8
The TACC for STA 8 increased from 22 t to 50 t in the 1993–94 fishing year under the AMP. Landings increased to 18 t in 1991–92 but have since declined to less than 5 t. The TACC was reduced back to 22 t in 1997, upon the removal of STA 8 from the programme. It is not known if recent catch levels and current TACC are sustainable. The status of STA 8 relative to BMSY is unknown.

Document date
Sunday, 31 May 2009

Document type
V 1.3

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Adobe PDF

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384.0 kb

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2009

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M:\SCIPOL\Working Groups 2009\Plenary 2009\FINAL\MFish 2009 May Plenary\May 2009 - PDF\96_STA_09.pdf

Uploaded date
Friday, 12 June 2009

Search tags

Species: STA;
Stock: STA1; STA10; STA2; STA3; STA4; STA5; STA7; STA8;

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