29_SKI_09

Filename
29_SKI_09.pdf

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29_SKI_09.pdf (243.7 kb)

Abstract
A new stock assessment was completed for SKI 1 & 2 in 2008.

SKI 1 & 2
Virgin and current biomass for the northern gemfish stock were estimated assuming one stock (SKI 1 & 2). Year class strengths from 1989 to 2000 appear to have been low, except for one strong cohort in 1991. Three alternative model runs were presented, all using the assumption that the commercial CPUE data are relative abundance indices up to 2001, but only using catch and catch at age data since 2001. The first model estimated the stock size (B2006) to be about 32% of B0 assuming recruitment since 2000 has been at the long-term average level. The second model assumed that recruitment has been at the long-term average level since 2001 and estimated the stock size (B2006) to be 26% of B0. The final model incorporated new catch at age (from 2007) and estimated individual year class strength up to 2003. This model estimated that current biomass (B2007) was about 22% of B0. For all three models, projections at the current TACC levels suggest the stock may increase with average recruitment (long term mean from 1978 to 2000), but is likely to decline if recruitment remains at the levels seen in more recent years (from 1992 to 2000).

SKI 3 & 7
The assessment of the southern gemfish stock has not been updated since 1997. Landings from SKI 7 increased from 2000 to be a level over twice the TACC in 2004–05, but have decreased since then.

Document date
Sunday, 31 May 2009

Document type
V 1.3

File format
Adobe PDF

File size
243.7 kb

Reference number
2009

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Uploaded from
M:\SCIPOL\Working Groups 2009\Plenary 2009\FINAL\MFish 2009 May Plenary\May 2009 - PDF\29_SKI_09.pdf

Uploaded date
Wednesday, 10 June 2009

Search tags

Species: SKI;
Stock: SKI1; SKI10; SKI2; SKI3; SKI7;

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