Stock assessment of east coast tarakihi (TAR 1,2,& 3)

Trophia was contracted by the New Zealand Ministry of Fisheries to develop a stock assessment model for Tarakihi (Nemadactylus macropterus) off the east coast of New Zealand. Specific objectives of the project were:

  1. To characterise the TAR 1 fishery and update the standardized CPUE indices for TAR 1 using data up to the end of the 2010/11 fishing year.

  1. To characterise the TAR 2 fishery and update the standardized CPUE indices for TAR 2 using data up to the end of the 2010/11 fishing year.

  1. To characterise the TAR 3 fishery and update the standardized CPUE indices for TAR 3 using data up to the end of the 2010/11 fishing year.

  1. Investigate stock relationships of east coast Tarakihi.

  1. To carry out a stock assessment of east coast tarakihi, including estimating biomass and sustainable yields.

Good correspondence between standardized CPUE trends for TAR 3 (Kaikoura setnet), TAR 2 (bottom trawl) and TAR 1 (Bay of Plenty) suggest that that tarakihi along the east coast north of Kaikoura comprise a single biological stock with an annual northward spawning migration. This is supported by the movement of tagged fish and temporal patterns of abundance off Kaikoura, in TAR 2 and in the Bay of Plenty. Consistent declines in CPUE since 2002/03 suggest that the stock is declining and that there is sufficient signal in the indices of relative abundance to achieve a stock assessment with reasonable certainty.