84 SCA7_09

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84 SCA7_09.pdf

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84 SCA7_09.pdf (194.0 kb)

Abstract
An estimate of current biomass is available for the SCA 7 fishery. Estimates of B0 and BMSY are not available, and are probably not appropriate reference points for a stock with highly variable recruitment and growth such as scallops.

There has been a substantial decline in the biomass of scallops in both Golden Bay and Tasman Bay since about 2002; current biomass is extremely low in Tasman Bay. In contrast, biomass in the Marlborough Sounds has remained relatively stable over the same period. The cause of the biomass decline in Golden Bay and Tasman Bay is unknown, but it is thought to be associated with factors other than simply the direct removals of scallops by fishing. Indirect effects of fishing and/or environmental factors could have influenced scallop abundance.

Recent SCA 7 landings have been low, and Tasman Bay has been completely closed to commercial harvesting since 2006. Catch has been consistently below the TACC, which is set at a relatively high level under section 14 of the Fisheries Act 1996 because of the rotationally enhanced management strategy. The intended strategy was to open sectors on a three yearly rotational basis, with reseeding at the end of the season. This has not always occurred however,particularly in recent years. It is thought now that the current practise of ‘rotational’ fishing on its own is probably not a sufficient strategy for the sustainable management of this fishery.

We do not understand the processes that result in large fluctuations in scallop abundance. To get sustainable yield from such a variable stock it is necessary to alter the catch every year. Management of the Marlborough Sounds region of the SCA 7 fishery and other New Zealand scallop fisheries (SCA1 and SCA CS) has been based on a Current Annual Yield (CAY) approach using F0.1 as an appropriate reference point, which is considered both appropriate andconservative.

Document date
Sunday, 31 May 2009

Document type
V 1.3

File format
Adobe PDF

File size
194.0 kb

Reference number
2009

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M:\SCIPOL\Working Groups 2009\Plenary 2009\FINAL\MFish 2009 May Plenary\May 2009 - PDF\84 SCA7_09.pdf

Uploaded date
Friday, 12 June 2009

Search tags

Species: SCA;
Stock: SCA7;

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