75_RCO_09

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75_RCO_09.pdf

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75_RCO_09.pdf (412.0 kb)

Abstract
Yearly fluctuations in red cod catch (t) reflect changes in recruitment. Trawl surveys and catch sampling of red cod have shown that the fishery is based almost exclusively on two and three year old fish and is highly dependent on recruitment success.

The disparity between the TACC and reported landings indicates that the TACC is not generally attainable. The rationale for introducing and retaining a TACC of this magnitude was to provide the fishing industry with the flexibility to capitalise on years when red cod are plentiful. TACCs were exceeded in 1994–95 and 1998–99, when total catches were the highest since the introduction of the QMS. However, since then total landings have declined and recent catches in the major Fishstocks have been lower than the YAV and MIAEL method MCY estimates.

RCO 1 & RCO 2
For RCO 1 and RCO 2 it is not known if the current TACCs and recent catch levels are sustainable or if they are at levels that will allow the stocks to move towards a size that will support the MSY.

RCO 3
An analysis of recruitment–environment relationship showed that in RCO 3 there is a strong correlation between recruitment and environmental variables with a periodic 14 month time lag. The stock assessment model was sensitive to inclusion of the environment abundance index which predicts a sharp decline in recruitment in recent years. However, the predictive power of the environment– abundance model in RCO 3 proved to be poor for the most recent years (i.e., YCS estimates low and landings high). For RCO 3 a constant catch at the level of the current TACC is unlikely to be attainable or sustainable in most years. Catches and the winter East Coast South Island survey biomass index in 2006–07 were at their lowest recorded levels. These low catch and biomass estimates are likely a function of a depressed population, rather than from recruitment failure. This conclusion is based on the similarity of the size distribution of red cod in the recent winter survey compared to that of previous surveys (Figure 2).

Stock Structure Assumptions
Stock boundaries are unknown, but for the purpose of this summary RCO 7 is considered to be a single management unit.

Document date
Sunday, 31 May 2009

Document type
V 1.3

File format
Adobe PDF

File size
412.0 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\75_RCO_09.pdf

Uploaded date
Thursday, 11 June 2009

Search tags

Species: RCO;
Stock: RCO1; RCO10; RCO2; RCO3; RCO7;

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