Rebuilding east coast tarakihi
Tarakihi, Nemadactylus macropterus, on the east coast of New Zealand appears to comprise a single biological stock. Tarakihi is a relatively long- lived species that reaches at least 40 years of age. Females mature at 6 years, after which they produce large numbers of pelagic (floating) eggs several times during each protracted summer/autumn spawning season. Following a 7 to 12 month pelagic phase, where the fertilised eggs, larvae and juvenile fish tend to remain in surface waters, east coast tarakihi mainly settle in nursery grounds off the east coast of the South Island, primarily the Canterbury Bight and Pegasus Bay. As they grow older, they move progressively further northward, with the highest proportions of older fish found off east Northland.
Research to monitor and rebuild tarakihi stocks
Stock assessments of east coast tarakihi are undertaken using a complex age- structured statistical model that accounts for gains and losses to the population, to provide an estimate of stock status in relation to the unfished level. The model is fitted to several sources of data, including annual landings, growth rates, age structure of trawl surveys, and commercial catches from different regions, indices of relative abundance based on trawl surveys and standardised commercial Catch per Unit of Effort (CPUE).
The first successful stock assessment for east coast tarakihi was completed in November 2017, and the assessment was updated in 2018, 2019, and 2022.
TACC reductions were implemented based on the stock assessment results in 2018, 2019, and 2022. The TACC reductions are predicted to rebuild the east coast tarakihi stock to the management target by 2037. In addition, a voluntary industry rebuilding plan is being implemented, which includes a number of additional measures:
- a move-on rule and research into mesh selectivity to avoid the capture of juvenile tarakihi
- voluntary closed areas
- limits on catches from the eastern parts of QMAs, TAR1, and TAR7.
Find out more about the rebuild of the east coast tarakihi fishery
The way forward for east coast tarakihi
The next stock assessment is scheduled for 2026. A national study of the age composition of the commercial catch in 2023/24 and 2024/25 will provide important inputs for the stock assessment model. East coast South Island trawl surveys, which also provide important information for the stock assessment, were conducted in 2022 and 2023 and are scheduled for 2025 and 2027.
The new stock assessment will be used to determine whether the stock is on track to rebuild to the target within the accepted time frame and whether further management intervention is required.
