A novel spatial risk assessment framework is proposed, based on the Spatially Explicit Fisheries Risk Assessment (SEFRA) and the Sustainability Assessment for Fishing Effects (SAFE). Risk is the probability that exploitation exceeds the Impact Sustainability Threshold (IST). Exploitation is estimated from the catchability and effort, using prior information on either the catchability or the population size. It is applied to shark and turtle species with different data characteristics.
This report documents the 2022 stock assessment of red rock lobsters in CRA 2. The model was fitted to length frequency data, sex ratio data, tag-recapture growth increment data, and standardised catch-per-unit-effort indices using the lobster stock dynamics model. This stock assessment estimated generally increasing exploitation rates throughout the stock’s history. Catch cuts and a period of improved recruitment have helped the stock rebuild since the 2017 stock assessment.
This report documents the data used by the 2022 stock assessment of red rock lobsters in CRA 2. The data sets described include: catch estimates from commercial, recreational, customary, and illegal components of the fishery; standardised catch-per-unit-effort indices; standardised catch length-frequency distributions and sex ratios; tag-based growth information; and the proportion of mature females that were in berry (egg-bearing).
A spatial analysis of catch and effort data from the SNA 1 bottom trawl fishery was used to refine the boundary of the East Northland and Hauraki Gulf snapper stocks. For the two stock units, bottom trawl CPUE indices were derived for the spring-summer period. The two sets of CPUE indices were included in the 2023 stock assessment of SNA 1.
A fully integrated stock assessment is presented for HOK 1 modelled with two stocks (western and eastern) and with fish residing in four regions. The western stock is estimated to be lower than the eastern stock, with biomass expected to be 25–43% B0 in 2027 under current catch levels for the western stock and 46–55% B0 for the eastern stock. A simpler model with one stock and one region estimated current biomass to be 37–45% B0 in 2022. Target range for hoki is 35–50% B0.
Characterisation and CPUE (catch-per-unit-effort) analysis for SCI 1 (Bay of Plenty) and SCI 2 (Hawke Bay-Wairarapa) scampi (Metanephrops challengeri). Scampi live in burrows and variability in emergence rates impact the relationship between CPUE and abundance. SCI 1 index increased from 2016 to 2021. SCI 2 CPUE generally declined from 2015 to 2021. The CPUE indices were accepted by the New Zealand Fisheries Deepwater Working Group as valid for tracking scampi biomass for use in the stock assessment.
For southern blue whiting on the Bounty Plateau (SBW 6B), a new Harvest Control Rule, HCR2022, was developed that allowed for consecutive years with no acoustic surveys. HCR2022 replaced the previous HCR which required an acoustic survey every year.