This report summarises MPI’s regulatory activities in the first quarter of the 2018 (1 January 2018 – 31 March 2018).

This report summarises MPI’s regulatory activities in the last quarter of the 2017 (1 October 2017 – 31 December 2017).

This report provides the results from the 2017 west coast South Island inshore trawl survey. It was the 13th survey in the series and continues to provide data to establish trends in biomass and length frequency distributions for the key species and other species which have been shown as being monitored. The consistence in design has enabled the results to be used as an important source for determining quotas for a range of species in the area covered.

Stock assessment of red rock lobsters in CRA 2 and management procedure evaluations current to 31 March 2017. The model was fit to standardised CPUE indices, size frequency, sex ratio, and tag-recapture data and used Bayesian inference to estimate parameter uncertainty. The assessment showed a stock depleted below BREF and low estimates of spawning stock relative to the unfished level. The assessment model was used as an operating model to evaluate the performance of alternative MPs.

This report updates the information on annual patterns of settlement for the red rock lobster (Jasus edwardsii) on crevice collectors at key sites in CRA 3 (Gisborne), CRA 4 (Napier and Castlepoint), CRA 5 (Kaikoura), CRA 7 (Moeraki), and CRA 8 (Halfmoon Bay and Jackson Bay). An annual raw and standardised index is produced from the groups of collectors at each site.

The fisheries taking snapper in SNA 2 were analysed from 1989–90 to 2015–16 based on commercial catch and effort data. SNA 2 is split into two areas (SNA 2N & SNA 2S) at the Mahia Peninsula, and combined CPUE indices created for each hypothesised sub-stock. The indices for both areas declined from 2001–02 to 2009–10. From 2009–10 the SNA 2N index displayed a slightly increasing trend, whereas the more volatile SNA 2S index had a decreasing trend.

This report presents additional assessments of hoki, hake and ling stocks using alternative catch histories. The assessments are for both hoki stocks (HOK 1 east, HOK 1 west), the three hake biological stocks (HAK 1 Sub-Antarctic, HAK 4 Chatham Rise, HAK 7 west coast South Island), and the three largest ling biological stocks (LIN 3&4 Chatham Rise, LIN 5&6 Sub-Antarctic, LIN 7 WCSI). Estimates of current stock status generally differed little from the base case model assessments.

A series of CPUE indices were compared with the available research trawl survey indices. Even when removing midwater trawl data, or using only data from the trawl survey area, or analysing separate fleets with consistent fishing gear and practice, the resulting CPUE trajectories were similar to that produced previously for the entire fishery. None of the series matched the research trawl survey indices. It is unlikely that any current WCSI hake CPUE series is a reliable index of fish abundance.
(Manuscript 3212)

An acoustic survey of spawning hoki abundance in Cook Strait was carried out from the research vessel Ikatere from 25 July to 27 August 2017 (IKA1701). The average abundance estimate over the six snapshots was 102 000 t, with a total CV of 36%. This was half of the equivalent estimate from 2015. Ikatere is not capable of mark identification trawling, so the only biological data available were from at-sea observers and land-based sampling of the commercial catch.

The FV Tomi Maru 87 collected acoustic data along 15 transects in one snapshot on the Bounty Plateau overnight on 5–6 September 2017. Spawning was very late in 2017, with running ripe females recorded northeast of the survey location on 1–4 September, and then close to the survey area on 7–9 September. The acoustic biomass estimate was 7719 t (CV 24%). This was 24% higher than the estimate from 2016, but still the third lowest in the industry acoustic time-series (which started in 2004).

The fisheries taking gurnard in GUR 2 were analysed from 1989–90 to 2015–16 using commercial catch and effort data. The majority of the GUR 2 catch was taken by the mixed species (gurnard, snapper and trevally) bottom trawl fishery within Hawke Bay and Poverty Bay. The accepted CPUE index using daily aggregated data gradually declined from 1989–90 to 2011–12 and then increased rapidly over the subsequent four years. This increase was corroborated by the recent, tow-based CPUE series.

The third fixed and second concurrent random site potting survey in the time series for Paterson Inlet. Sixty-three sites were surveyed (6 pots per site, 378 pot lifts) from 5 strata. Pot catch weighed, length and sex of blue cod recorded. Otoliths from random and fixed sites produced age-length keys applied to the scaled length frequency distributions to estimate the population age structures. Estimates of Z and F%SPR indicate that spawning biomass has been reduced to 30-39%.

Second random site potting surveys in the time series. Forty potting sites surveyed (6 pots per site = 240 pot lifts) from six strata. Pot catch weighed, length and sex of blue cod recorded. Otoliths age-length keys applied to the scaled length frequency distributions estimate population age structures. Estimates of Z and F%SPR indicate spawning biomass reduced to 57% (inshore) and 74% (offshore). Density/pot catch relationships differ among areas imply pot catchability is spatially variable.

Third fixed and first random site potting surveys in north Otago time series. Twenty-seven fixed and 40 random sites surveyed (6 pots per site, 402 pot lifts) from 4 coastal and 2 offshore strata. Pot catch weighed, length and sex of blue cod recorded. Otoliths from random and fixed sites produced age-length keys applied to the scaled length frequency distributions to estimate the population age structures. Estimates of Z and F%SPR indicate that spawning biomass has been reduced to 34-36%.