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This site contains documents relating to Fisheries New Zealand and predecessors’ funded research from 1988 to the current date. To find the documents applicable to you, please expand the filter and select the relevant search parameters. If you identify errors or inconsistencies in the categorisation of specific documents please advise us by emailing Science Officer.
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2445 items (1 to 50 shown)
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Title: AEBR 331 Assessing inter-annual variability in Antipodean albatross distribution
AEBR-331-Antipodean-albatross-distributions.pdf (7.5 MB)
Antipodean albatross breed on Antipodes Islands, to the south of New Zealand. They travel from there across the southern Pacific Ocean. The albatrosses have been tracked using tags that record their location. In this study, the tracking data were analysed. Males and females, and birds of different ages, tend to use different areas. Females travel more to the west, to the Tasman Sea, while males go further south. Young birds and breeding birds stay closer to New Zealand than non-breeding adults. The study found three places the birds consistently use a lot—the ocean east of New Zealand, the Tasman Sea between Australia and New Zealand, and an area off the coast of Chile in South America. By comparing the overlap between the distribution of the albatrosses and fishing activity, places were identified where albatrosses could accidentally get caught on fishing lines. This research could be used to help understand how fishing is impacting Antipodean albatross.
AEBR: 331;
ISBN: 978-1-991285-70-6;
ISSN: 1179-6480;
AUTHOR: Richard, Y.;; Tremblay-Boyer, L.;; Berkenbusch, K.;; Wilkinson, N.;; Walker, K.; Elliott, G.;
Title: FAR 2024/24 Simulation testing recruitment productivity shifts based on the 2021 SNA 8 stock assessment
FAR-2024-24-Simulation-Testing-Recruitment-Regime-Shifts-SNA8-2021-Stock-Assessment-4474.pdf (2.0 MB)
This project used simulation modelling to explore potential bias in snapper SNA 8 stock assessments when there has been a change in stock productivity (i.e., regime-shift), as may be expected under climate change.
Three SNA 8 stock productivity-change scenarios were investigated: the first assumed an upward shift in productivity after 2000; the second assumed a downward productivity shift after 2000; the third had no productivity shift.
Various SNA 8 stock assessment models were run under these productivity shift scenarios including one that explicitly allowed for a post-2000 productivity shift. Assessment bias was investigated specific to two important management metrics: current-stock-biomass; current-stock-status (being the ratio of current-stock-biomass to stock virgin (unexploited) biomass).
All assessment models produced unbiased estimates of current-stock-biomass under the no-regime-shift scenario. Only the post-2000 productivity shift model produced unbiased current-stock-biomass estimates under increasing and decreasing productivity scenarios.
All model current-stock-status estimates were biased under increasing and decreasing productivity scenarios. Although the post-2000 productivity shift model current-stock-status estimates were markedly less biased that those of the other models. An important finding from the study was all models were substantive
FAR: 2024/24;
AUTHOR: Marsh, C.; McKenzie, J.R.; Langley, A.D.;
ISSN: 1179-5352;
ISBN: 978-1-991285-45-4;
Title: FAR 2024/23 The 2023 stock assessment of red rock lobsters (Jasus edwardsii) in CRA 6
FAR-2024-23-The-2023-Red-Rock-Lobster-Stock-Assessment-For-CRA6-4477.pdf (20.8 MB)
The red rock lobster supports the most valuable inshore commercial fishery in New Zealand.

This fishery has been managed with catch quotas in nine Quota Management Areas (QMAs), which are usually treated as independent populations or stocks.

To estimate those quotas, a stock assessment is done for each QMA approximately every five years. These stock assessments include a review of the previous stock assessments and data inputs, the addition of new data, data processing, and development of a new stock assessment model.

This document describes the development of a new stock assessment model for the CRA 6 stock (the Chatham Islands).

The stock assessment estimated that since 1995, the stock size has steadily increased and is projected to increase over the next five years assuming current catches and recent recruitment patterns.
FAR: 2024/23;
AUTHOR: Rudd, M.B.; Webber, D.N.; Starr, P.J.; Roberts, J.O.; Pons, M.;
ISBN: 978-1-991285-41-6;
ISSN: 1179-5352;
Title: 2024/21 Recreational harvest of southern bluefin tuna in New Zealand, 2022–23
FAR-2024-21-New-Zealand-Southern-Bluefin-Tuna-Recreational-Harvest-2022-23-4447.pdf (752.7 kb)
This report estimates the total recreational catch of southern bluefin tuna in New Zealand for the 2022–23 fishing year.

Tuna numbers and weights are collected using a monthly telephone survey of South Island fishers and a boat ramp survey at Waihau Bay in the eastern Bay of Plenty where most of these fish are landed.

Catch records from fishing clubs, online reporting, and recreational charter boats are also used.

In 2022–23, the Total Allowable Catch of New Zealand southern blue tuna was 1102 tonnes. The Commission for the Conservation of Southern Bluefin Tuna requires member countries to report their total catch.

Overall the number of southern bluefin tuna caught in the rereational fishery was about 1500, which is more than in previous years, but the average weight was lower.

The total landed weight for the recreational fishery was estimated to be between 65 and 73 tonnes with a mi
FAR: 2024/21;
AUTHOR: Holdsworth, J.C.;
ISSN: 1179-5352;
ISBN: 978-1-991285-39-3;
Title: AEBR 330 Non-target fish and invertebrate catch and discards in New Zealand hoki, hake, ling, silver warehou, and white warehou trawl fisheries from 2002–03 to 2021–22
AEBR-330-Non-Target-Catch-In-Hoki-Hake-Ling-Silver-And-White-Warehou-Fishery-To-202122-4476-2024.pdf (16.4 MB)
Most fishing methods catch target and non-target (unwanted) species, and unwanted catch may be returned to the sea in some cases. Fishers and observers record catches of target and non-target species, and the amount of catch returned to the sea (discards).
Total non-target catch and discards for key species and species groups reported in the hoki, hake, ling, silver warehou, and white warehou (HHLSW) fishery from fishing years 2003 to 2022 were estimated with a statistical model.  
Hoki and other target species make up most of the catch in this fishery, and key non-target species inluded javenlinfish, rattails, and sharks. 
Gemfish showed a significant increasing trend in the amount of non-target catch reported, and sharks and slickheads showed significant decreasing trends. 
The amount of catch that is discarded compared with the target catch is lower for this combined fishery than for other fisheries that are monitored. 
Monitoring levels of catch and discards is important for understanding the impact of fishing on the environment.
AEBR: 330;
ISBN: 978-1-991285-38-6;
ISSN: 1179-6480;
AUTHOR: Finucci, B.; Anderson, O.F.; Edwards, C.T.T.;
Title: FAR 2024/22 Pāua population monitoring in areas affected by the November 2016 Kaikōura earthquake, November 2023 update
FAR-2024-22-Kaikoura-Paua-Population-Monitoring-Update-November-2023-4448.pdf (2.5 MB)
The 2016 Kaikōura earthquake caused significant coastal uplift resulting in high mortality of marine life, including pāua.

The pāua fishery is of high importance to customary, recreational, and commercial fishers in the region.

We undertook dive surveys to measure the recovery of the pāua populations on the affected coastline and have continued surveys since the fishery re-opening in 2021.

 This report provides an update of survey results that have now been undertaken annually over 6 years.

Surveys have shown a steady increase of pāua abundance across the fishery and an increasing abundance of smaller pāua suggesting successful post-earthquake recruitment (appearance of juveniles in the population). 

Data and outcomes from these surveys were used to inform the decision to
ISBN: 978-1-991285-40-9;
ISSN: 1179-5352;
FAR: 2024/22;
AUTHOR: McCowan, T.A.; Neubauer, P.;
Title: FAR 2024/20 Investigating monitoring and assessment approaches for oreo species
FAR-2024-20-Monitoring-And-Assessment-Approaches-For-Oreo-Species-4387.pdf (5.1 MB)
Two oreo species, black oreo and smooth oreo, are commercially important in New Zealand waters. 
Oreos are deepwater fish and so are not very productive which means they can be easily over-exploited.
Management is based on setting catch quota for each oreo management area, but some areas have localised fisheries which are assessed separately to avoid over-exploitation.   
To assess if catch quotas are sustainable, abundance trends are produced from acoustic surveys and/or catch per unit effort (CPUE) series from the commercial fisheries within a quantitative assessment. 
Reductions in fishing effort and quotas have made acoustic surveys too expensive to fund from a levy on catch quotas and CPUE series in several areas have gone from accepted to rejected as a reliable indication of stock abundance trend, so quantitative assessments have been curtailed.
This study considered a range of different assessment methods and their data requirements in anticipation of lower-level monitoring and, for each oreo fishery, presents the monitoring and assessment options.
For two management areas (OEO 3A and OEO 4), acoustic surveys are still considered feasible if redesigned to reduce costs. Quantitative assessments are also considered possible and a method to explicitly consider spatial variation of CPUE within the area is demonstrated in this work as a way to improve the CPUE input data.
For t
AUTHOR: Doonan, I.J.; Ladroit, Y.; Holmes, S.J.; Datta, S.;
FAR: 2024/20;
ISSN: 1179-5352;
ISBN: 978-1-991285-35-5;
Title: FAR 2024/19 Data for the 2023 stock assessment of red rock lobsters (Jasus edwardsii) in CRA 6
FAR-2024-19-Data-For-2023-Red-Rock-Lobster-CRA6-Stock-Assessment-4470.pdf (15.5 MB)
The red rock lobster supports the most valuable inshore commercial fishery in New Zealand. This fishery has been managed with catch quotas in nine Quota Management Areas (QMAs), which are usually treated as independent populations or stocks.
To estimate those quotas, a stock assessment is done for each QMA approximately every five years. These stock assessments include a review of the previous stock assessments and data inputs, the addition of new data, data processing, and development of a new stock assessment model.
This document describes the collation and review of inputs for the 2023 stock assessment of CRA 6 (the Chatham Islands).
FAR: 2024/19;
AUTHOR: Webber, D.N.; Roberts, J.O.; Starr, P.J.; Rudd, M.B.; Pons, M.;
ISSN: 1179-5352;
ISBN: 978-1-991285-30-0;
Title: AEBR 329 Spatially explicit benthic impact assessments for bottom trawling in New Zealand
AEBR-329-Spatially-Explicit-Benthic-Impact-Assessment-For-Bottom-Trawling-4430-2024.pdf (24.7 MB)
The trawl footprint describes how much seabed area has been contacted by trawling gear in New Zealand’s territorial sea (TS) and exclusive economic zone (EEZ), but it does not provide a measure of the effect of fishing on seabed communities. 
This project used the trawl footprint information, in addition to other sources of information on impacts of contact by trawl gear on seabed fauna, to quantify the potential impacts to seabed communities and habitats. 
Fishing gear types were first described and categorised, and footprints for each category of gear were produced. Two published impact assessment methods were applied to the TS and EEZ. The methods had different strengths and weaknesses and the outputs of the two methods were found to be complementary to one another. 
The first method applied, the MRSP approach, combines information on gear categories, expert opinion on the vulnerability of seabed fauna to trawl gear, and the bottom contact footprint of trawl fishing. This approach does not consider how the fauna recover over time. 
The second method, the relative benthic status (RBS) approach, uses information on the proportion of the seabed area swept by trawls and published information for depletion and recovery rates for seabed fauna considered to be particularly vulnerable to trawling. This method predicts a future state for th
AEBR: 329;
AUTHOR: Rowden, A.A.; Anderson, O.F.; Neubauer, P.; Hamill, J.; Bowden, D.A.; Tremblay-Boyer, L.; Charsley, A.; MacGibbon, D.;
ISSN: 1179-6480;
ISBN: 978-1-991285-28-7;
Title: FAR 2024/18 Inshore trawl survey off the west coast North Island, October 2022 (KAH2205)
FAR-2024-18-Inshore-Trawl-Survey-West-Coast-North-Island-October-2022-KAH2205-4446.pdf (13.8 MB)
This report presents results of the 2022 inshore trawl survey of the west coast North Island (WCNI), the 9th in a time series starting in 1989, but with a 19-year gap between 1999 and 2018 surveys.
The survey extends from Scott Point on Ninety Mile Beach to Mana Island covering a depth range from 10–200 m north of Cape Egmont and 10–100 m to the south. Since 2018, there has been no sampling within 2–4 nautical miles of the coast between Maunganui Bluff and the Waiwhakaiho River, New Plymouth, a no-trawl area established to protect the Māui dolphin.
Everything that is caught in the trawl is sorted, identified, and weighed, and length and maturity data are collected for selected species and otoliths (fish ear stones) for ageing the four main species of interest: snapper, red gurnard, John dory, and tarakihi. The trawl survey provides time series of relative biomass estimates and age, length, and maturity stage information used for stock assessments and fisheries management advice for key inshore species.
In 2023, 95 phase one stations were successfully completed followed by four phase two stations completed to improve the coefficient of variation for tarakihi.
There were 72 species recorded in total, with snapper by far the most abundant. Biomass estimates (in tonnes) for the key species across the whole survey were: snapper, 8396.3 t ; red gur
FAR: 2024/18;
AUTHOR: Jones, E.G.; Underwood, M.J.; Bian, R.; Walsh, C.; O’Driscoll, R.L.;
ISSN: 1179-5352;
ISBN: 978-1-991285-27-0;
Title: FAR 2024/17 Mortality rates of snapper released by recreational fishers
FAR-2024-17-Mortality-Rates-Of-Snapper-Released-By-Recreational-Fishers-4409.pdf (2.4 MB)
Snapper are the most important recreational fish species in New Zealand and are often released back to the sea after capture.
Little is known about the survival of fish after they are released.
NIWA conducted a study using volunteer fishers to catch 960 snapper at different depths and with different hook placements.
The captured snapper were kept in holding nets and monitored by NIWA divers over several days.
Fish hooked in the lip had a low chance of dying if caught at shallow depths, but the chance of dying increased as depth increased.
Fish hooked elsewhere on the body had a higher chance of dying, with those hooked deep in the gut having the highest chance of dying.
This study suggests that fishing practices can impact fish survival, but there are ways to potentially reduce post-release mortality.
Understanding how fishing affects fish survival is therefore an important consideration for catch and release fisheries and when setting catch limit regulations.
FAR: 2024/17;
ISBN: 978-1-991285-24-9;
ISSN: 1179-5352;
AUTHOR: Maggs, J.Q.; Hartill, B.W.; Evans, O.E.; Holdsworth, J.C.; Lumley, T.; Stevens, T.;
Title: FAR 2024/16 Catches and size and age structure of the 2021–22 hoki fishery and a summary of input data used for the 2023 stock assessment
FAR-2024-16-Catches-And-Size-And-Age-Structure-202122-Hoki-Fishery-Inputs-for-2023-Assessment-4424.pdf (20.2 MB)
This report updates and summarises the commercial catches, standardised catch per unit effort (CPUE), and observer and research data for hoki (Macruronus novaezelandiae) caught commercially during the 2021–22 fishing year.
These data include time series of length-at-age and catch-at-age from observer and land-based sampling of commercial catch. Length and age data from spawning and non-spawning fisheries are compared with those from previous years.
The overall catch in the 2021–22 fishing year was lower than the catch in 2020–21. Catches in 2021–22 decreased in most areas (west coast South Island, Cook Strait, Chatham Rise, Sub-Antarctic, and east coast North Island) and increased in the east coast South Island and Puysegur fisheries. The CPUE indices varied by area but were all at or above the long-term average.
Catch-at-age data are important for the assessment of fish stocks because they provide information on the year class strength of age classes caught and are used in analyses of trawl surveys and commercial fisheries. Most of the catch in 2021–22 was of fish 45–90 cm length from the 2006–2019 year classes.
The 2014 and 2015 year classes were important in all areas except for the Chatham Rise, and the 2016 and 2017 year classes were low in all the main fisheries. The 2018 and 2019 year classes appeared strong in
FAR: 2024/16;
ISBN: 978-1-991285-23-2;
ISSN: 1179-5352;
AUTHOR: Ballara, S.L.; O’Driscoll, R.L.;
Title: FAR 2024/15 Trawl survey of hoki and middle-depth species in the Southland and Sub-Antarctic areas, November–December 2022 (TAN2215)
FAR-2024-15-Hoki-And-Middle-Depth-Trawl-Survey-Southland-And-SubAntarctic-2022-TAN2215-4437.pdf (18.3 MB)
This report provides results for the 20th summer trawl survey of hoki, hake, ling, and associated species in the Sub-Antarctic carried out from 23 November to 23 December 2022. Seventy-four of the 80 planned phase one stations were completed; there was no time to carry out phase two.
When compared with the previous survey in 2020, biomass estimates in core strata (200–800 m depths) were up by 31% for hoki, up by 10% for ling, and down by 25% for hake. The precision target (coefficient of variation) of 15% was met for hoki and ling but slightly exceeded for hake.
The hoki length and age distributions were mainly adult fish with few 1+ fish (2021 year class, fish less than 45 cm) and few 2+ fish (2020 year class, 45–55 cm). The hake and ling length and age distributions were broad, with few juvenile fish. 
The acoustic estimate of midwater fish abundance was lower than that in 2020 but still above the average of the time series.
A total of 188 species or species groups were caught, of which 88 different species of fish and squid (29 560 fish) were measured, and 12 320 fish were individually weighed during the survey.
FAR: 2024/15;
ISSN: 1179-5352;
ISBN: 978-1-991285-12-6;
AUTHOR: Stevens, D.W.; MacGibbon, D.J.; Ballara, S.L.; Wieczorek, A.M.; Barnes, T.C.; Stevens, D.W.; MacGibbon, D.J.; Ballara, S.L.; Wieczorek, A.M.; Barnes, T.C.;
Title: FAR 2024/14 Catch-at-age from commercial fisheries and trawl surveys for hake (Merluccius australis) and ling (Genypterus blacodes) in 2021–22
FAR-2024-14-Commerical-Fisheries-And-Research-Surveys-Hake-And-Ling-Catch-At-Age-202122-4429.pdf (24.5 MB)
This report describes catch-at-age distributions for hake (Merluccius australis) and ling (Genypterus blacodes) from commercial fisheries for the 2021–22 (2022) fishing year, to update an ongoing time series.
These distributions are based on length data and otoliths (ear bones for ageing fish) collected by observers from commercial fishing and research trawl data.
Catch-at-age data are important for the assessment of fish stocks because they provide information on the year class strength of age classes caught and are used in analyses of trawl surveys and commercial fisheries.
The precision target (coefficient of variation) was met for analyses of hake commercial trawl Sub-Antarctic and west coast South Island fisheries but not for the Sub-Antarctic trawl survey. The target precision was met for the Chatham Rise and Sub-Antarctic ling commercial trawl fisheries, and the Sub-Antarctic trawl survey, but not for the west coast South Island commercial trawl fishery. The target precision was met for the west coast South Island and Sub-Antarctic ling longline fisheries analysed.
Further observer data collection in certain areas and months are recommended to improve the precision of the hake and ling time series in future analyses.
FAR: 2024/14;
ISSN: 1179-5352;
ISBN: 978-1-991285-07-2;
AUTHOR: Ballara, S.L.; Barnes, T.C.;
Title: AEBR 328 Recovery of rocky intertidal and subtidal communities affected by the 2016 Kaikōura earthquake and coastal uplift: 6-year assessment.
AEBR-328-6-Year-Assessment-Rocky-Intertidal-And-Subtidal-Communities-Post-Kaikoura-2016-Quake-2024-4435.pdf (14.1 MB)
 The Marine Ecology Research Group used detailed field surveys to assess the recovery of the inshore coastal ecosystem affected by the cataclysmic 2016 Kaikōura earthquake.
The earthquake caused seismic uplift from 0.5 to 6.4 m along 130 km of coastline and resulted in widespread die-offs of important flora and fauna and permanent losses to critical habitats.
There was much concern for the fate of diverse intertidal and subtidal communities, which include culturally and commercially important fisheries, such as pāua, and other habitat-forming species like bull kelp.
Shore-based and dive surveys tracked the abundance of over 120 marine species at 16 sites for more than six years. Findings depict major physical and ecological changes over time across sites.
The complex dynamics of recovery are described in detail in this report and clearly show that the effects from this disturbance to the Kaikōura coastal ecosystem are both significant and ongoing.
This long-term study is the first of its kind and provides a detailed data set and quantitative baselines that will help inform future coastal management decisions.
AEBR: 328;
ISSN: 1179-6480;
ISBN: 978-1-991285-06-5;
AUTHOR: Schiel, D.R.; Falconer, T.R.L.; Gerrity, S.; Dunmore, R.A.; Crossett, D.; Virgin, S.D.S; Alestra, T.; Orchard, S.;
Title: AEBR 327 Novel technologies to monitor Māui and Hector’s dolphins: DTAG feasibility trial
AEBR-327-Novel-Technologies-To-Monitor-Hectors-And-Maui-Dolphins-DTAG-feasibility-2024-4462.pdf (3.6 MB)
 With funding from Fisheries New Zealand and support from the Department of Conservation (DOC), we trialled attaching short-term (24 hours) suction-cup recording tags (DTAGs) to Hector’s dolphins in Te Koko-o-Kupe/Cloudy Bay. 
We wanted to determine if DTAGs are a possible tool for monitoring this endangered species and could help answer research gaps identified by DOC’s Threat Management Plan and Research Strategy.
We found these suction-cup DTAGs had little to no impact on Hector’s dolphin behaviour.
We tagged 11 dolphins, and their tags stayed attached for 1.5 to 24 hours.
We gathered over 83 hours of data on this species, including:
the first ever three-dimensional recordings of Hector’s dolphin underwater, 
their night-time movements, and 
recordings of the different sounds they make and hear during a typical day.
Overall, such insights about these dolphins can influence how we manage them in relation to their various threats.
AUTHOR: Clement, D.; Pavanato, H.; Belonovich, O.; Childerhouse, S.; Constantine, R.; Johnson, M.; MacKenzie, D.; Ogle, M.; van Helden, A.; Williams, R.;
AEBR: 327;
ISBN: 978-1-991285-05-8;
ISSN: 1179-6480;
326 15/03/2024
Title: AEBR 326 Cyclone impacts on fisheries
AEBR-326-Cyclone-Impacts-On-Fisheries-2024-4461.pdf (25.3 MB)
Increasingly frequent and intense extreme weather events such as Cyclone Gabrielle are likely to impact seafloor marine ecosystems by accelerating soil erosion and sediment transport to the ocean by rivers. 
The objective of this project was to understand sediment impacts from the February 2023 Cyclone Gabrielle event on marine environments of the Hawke’s Bay and Gisborne regions to enable rapid fisheries management decisions. 
We conducted two vessel surveys in June and October 2023 focusing on offshore seabed environments deeper than 15 metres. As part of these surveys we mapped selected areas of the seafloor, surveyed life on the seabed using a towed underwater camera, and obtained sediment core samples. 
An ocean current and sediment transport model was designed and implemented to investigate the transport and deposition of sediments after Cyclone Gabrielle. Concentrations of suspended sediments and other parameters in the surface ocean along the east coast of the North Island were estimated from satellite images. This satellite information was used to inform the sediment transport model and to characterise the spatial extent and longevity of the offshore sediment plumes generated by Cyclone Gabrielle. A Seafloor model was used to explore impacts and recovery of seafloor ecosystems following the cyclone.
The analysis of satellite image
AUTHOR: Leduc, D.; Collins C.; Gall M.; Lundquist, C.; Macdonald, H.; MacKay, K.; Mountjoy J.; Morrison, M.; Orpin, A.; Pinkerton, M.; Spain, E.; Barry, F.; Bodie, C.; Carson-Groom, E.; Connell, A.; Fenwick, M.; Frontin-Rollet, G.; Halliday, J.; Leunissen, E.; Madden, B.; Mason, G.; Maurice, A.; Nepia-Su’a, A.; Olsen, G.; Peart, R.; Quinn, W.; Stewart, R.; Toataua, N.;
AEBR: 326;
ISSN: 1179-6480;
ISBN: 978-1-991087-55-3;
Title: FAR 2024/13 Rapid updates for New Zealand rock lobster (Jasus edwardsii) stocks in 2023
FAR-2024-13-The-2023-Rapid-Updates-For-Rock-Lobster-Stocks-4454.pdf (10.8 MB)
The red rock lobster supports the most valuable inshore commercial fishery in New Zealand. This fishery has been managed with catch quotas in nine Quota Management Areas (QMAs), which are usually treated as independent populations or stocks.
To estimate those quotas, each population is fully assessed every five years, requiring a lot of time and effort by a team of at least five researchers working on the review of the previous assessments and data inputs, the addition of new data, data processing, and development of a new assessment.
Every year, instead of a full assessment, a rapid update assessment is done for each of the stocks that were not assessed that year.
A rapid update repeats the previous full assessment model, only updating data inputs, which significantly speeds up the required process to provide advice about stock status in the interim years between full assessments.
This document describes the operation of the stock assessment rapid updates completed in 2023 for six stocks that can be used to guide management decisions of New Zealand red rock lobster QMAs.
For the beginning of the 2023–24 fishing year, all red rock lobster stocks evaluated were estimated to be above sustainable levels.
AUTHOR: Pons, M.; Webber, D.N.; Rudd, M.B.; Starr, P.J.; Roberts, J.;
ISBN: 978-1-991087-54-6;
FAR: 2024/13;
ISSN: 1179-5352;
Title: FAR 2024/12 A 2020 preliminary stock assessment of ORH 7B
FAR-2024-12-2020-Preliminary-Stock-Assessment-ORH7B-4123.pdf (908.4 kb)
This report presents an assessment of the orange roughy stock off the west coast of the South Island (ORH 7B) in 2020. There was a fishery from 1985 to 1992, with the TACC peaking at 1708 t between 1989 and 1995, and the fishery was closed from October 2007. The assessment used two acoustic biomass estimates (2017, 2019) and a 2019 age frequency, completely rejecting the assumptions used in previous assessments that CPUE was directly proportional to biomass and that recruitment followed the assumed recruitment curve. This assessment is considered preliminary as work was stopped due to the conclusion that the acoustic surveys had probably missed a substantial proportion of the spawning biomass.
FAR: 2024/12;
ISSN: 1179-5352;
ISBN: 978-1-991120-96-0;
AUTHOR: Deepwater Group Ltd.;
Title: FAR 2024/10 Rock lobster catch and effort data: 1979–80 to 2022–23
FAR-2024-10-Rock-Lobster-Catch-And-Effort-Data-197980-To-202223-4455.pdf (5.6 MB)
 This report summarises commercial catch and effort statistics for rock lobsters, which are also known in New Zealand as “crayfish” or “kōura”. 
The summaries presented in this document cover the rock lobster legal fishing years (1 April–31 March) for April 1979 to March 2023.
There are nine Quota Management Areas (QMAs) that cover all inshore waters of the North Island, the South Island, and the Chatham Islands. There are 43 smaller statistical areas that lie within these nine QMAs. The summaries are ordered by QMA, with each QMA identified by a three-letter code and a number. The rock lobster code is CRA, so the nine QMAs are labelled CRA 1 to CRA 9. 
The first three tables for each CRA QMA summarise, by statistical area and fishing year, (1) number of vessels, (2) catch, and (3) effort. The last category is defined as the total number of rock lobster pots lifted within each fishing year and statistical area. The fourth table summarises catch by month and fishing year for the entire QMA, and a fifth table gives the monthly catch by statistical area for just the final fishing year, which is 2022–23 in this document. 
The sixth table for each QMA summarises catch-per-unit-effort (CPUE) by statistical area and fishing year. CPUE in this table is defined as the catch (in kilograms) from the second table div
FAR: 2024/10;
AUTHOR: Starr, P.J.;
ISSN: 1179-5352;
ISBN: 978-1-991120-94-6;
Title: FAR 2024/11 A 2020 Stock Assessment Update of ORH 3B East and South Chatham Rise
FAR-2024-11-2020-Stock-Assessment-Update-ORH3B-East-And-South-Chatham-Rise-4122.pdf (974.2 kb)
This report provides a 2020 update of 2014 and 2017 assessments of the East and South Chatham Rise orange roughy stock, to enable an HCR-derived recommended catch limit for 2020–21. Three age-structured Bayesian population models were fitted to biomass and composition data. Virgin biomass (B0) was estimated as 300 000–350 000 t and 2020 stock status from the base case model was 36% B0 (± 95% CIs of 30 to 41%). With a vulnerable biomass of 157 000 t, the HCR-derived recommended catch limit was 6348 t for 2020–21, with a slowing increasing population over future years.
FAR: 2024/11;
ISSN: 1179-5352;
ISBN: 978-1-991120-95-3;
AUTHOR: Deepwater Group Ltd.;
Title: FAR 2024/09 Estimation of finfish release survival from New Zealand inshore commercial fisheries
FAR-2024-09-Estimation-Of-Release-Survival-for-Inshore-Finfish-From-Commercial-Fisheries-4459.pdf (11.0 MB)
this study estimated the post-release survival of inshore finfish with current commercial minimum legal sizes—blue cod, blue moki, butterfish, kingfish, red moki, red cod, sand flounder, snapper, tarakihi, trevally, and yellowbelly flounder—and those currently allowed to be returned under disposal code X— kingfish, rig, sand flounder, school shark, rough skate, smooth skate, and spiny dogfish.
A questionnaire was developed and circulated to fishers, fishery observers, and scientists with knowledge of each species to obtain their estimates of at-release survival (i.e., the probability the fish/shark was alive when put back into water) and post-release survival (the probability an individual was both alive at release and survived following release). Estimates were obtained for each gear type as well as fishing categories within each gear type, e.g., duration, depth, and bag size. For some species, estimates of post- release survival were informed by literature on the survival of same or similar species.
These data were used with fishery characterisations to model the survival for each species. For species with a minimum legal size, both at-release and post-release survival estimates were used, whereas for those species released under disposal code X, which may only be released if alive and likely to survive, only the post-release survival estimates were used.
AUTHOR: McKenzie, J.R.; Underwood, M.J.; Jones, E.G.; Jordan, L.; Bian, R.;
FAR: 2024/09;
ISSN: 1179-5352;
ISBN: 978-1-991120-85-4;
Title: FAR 2024/08 Commercial catch sampling for species proportion, sex, length, and age of jack mackerels in JMA 7 in the 2021–22 fishing year, with a summary of all available data sets.
FAR-2024-08-Commerical-Catch-Sampling-of-Jack-Mackerels-JMA7-To-202122-4431.pdf (4.0 MB)
Jack mackerels (JMA) support significant commercial fisheries in New Zealand, with over 75% of the total jack mackerel catch taken by trawl fisheries off the west coasts of the North Island and South Island, in JMA 7. Three jack mackerel species are found in New Zealand waters, namely Trachurus declivis, T. murphyi, and T. novaezelandiae.
New Zealand commercial catches of jack mackerels have been recorded under the general code JMA. Therefore species-specific catch information is not available from the fishery data. Estimates of proportions of the three Trachurus species in the catch, based on observer data which includes separate codes for each species, are essential for assessment of the individual stocks.
This report updates the data collected by the New Zealand observer sampling programme from trawl landings of  jack mackerels in JMA 7 with the data collected during the 2021–22 fishing year, including estimates of species proportions and sex ratios in the landings, catch-at-length (fork length, cm), and catch-at-age for these species.
Estimated proportions of catch by species based on observer data have historically shown that T. declivis comprises 61–73% of the catch for all statistical areas, followed by T. novaezelandiae at 21–33%, and T. murphyi at 2–8%. In 2021–22, proportions of T. declivis, T. novaezelandiae, and T. murphyi were 77%, 23%, and le
FAR: 2024/08;
ISSN: 1179-5352;
ISBN: 978-1-991120-83-0;
AUTHOR: Moore, B.R; Ó Maolagáin, C.; Spong, K.; Barnes, T.;
Title: FAR 2024/07 Estimation of release survival of pelagic sharks and fish in New Zealand commercial fisheries
FAR-2024-07-Estimation-Of-Release-Survival-Of-Pelagic-Sharks-And-Fish-4445.pdf (9.7 MB)
 This project estimated survival of six pelagic species (southern bluefin tuna, Pacific bluefin tuna, swordfish, blue shark, mako shark, and porbeagle shark) following release from commercial fishing gear to inform a government review of their landing exceptions.
Fishery characterisations revealed that the main fishing gears responsible for discarded fish were surface longline (all species) and trawl (swordfish, mako, and porbeagle).
Literature reviews were conducted to document current knowledge on the status of an individual when brought to the vessel and ‘post-release’ survival (i.e., survival in the weeks to months following release) from these methods, as well as the factors that affect survival of each species. The key results were:
Bluefin tunas (including southern bluefin tuna and Pacific bluefin tuna) and swordfish typically have high post-release survival following capture by surface longline, with most studies reporting survival rates of 88% or greater for bluefin tunas and 50–88% for swordfish.
Blue shark have high at-vessel and post-release survival following capture by surface longline, with most studies reporting at-vessel and post-release survival rates of > 80%.
Mako have moderate to high at-vessel and post-release survival following capture by surface longline, with most studies reporting at-vessel and po
FAR: 2024/07;
ISSN: 1179-5352;
ISBN: 978-1-991120-82-3;
AUTHOR: Moore, B.R.; Finucci, B.;
Title: FAR 2024/06 Inshore trawl survey off the west coast South Island and in Tasman Bay and Golden Bay, March–April 2023 (KAH2302)
FAR-2024-06-Inshore-Trawl-survey-WCSI-And-Tasman-Bay-Golden-Bay-March-April-2023-KAH2302-4450.pdf (6.7 MB)
This report presents the results from the 16th inshore trawl survey in a time series started in 1992 along the west coast of the South Island, from Farewell Spit to the Haast River mouth, and in Tasman Bay and Golden Bay.
The survey covers depths from 20 to 400 m (core strata) and surveys many species but is mainly focused on giant stargazer, red cod, red gurnard, spiny dogfish, and tarakihi. Since 2017, two additional strata have been surveyed in 10–20 m in Tasman Bay and Golden Bay to cover the full distribution of snapper in the geographic area.
Data collected include length, weight, and maturity data for selected species, and collection of otoliths (fish ear stones) of the key species for ageing. The trawl survey provides time series of relative biomass estimates and age, length, and maturity stage information used for stock assessments and fisheries management advice for key inshore species.
In 2023, 58 phase one stations were successfully completed in the core strata and another six were carried out in strata 20 and 21. Four phase two stations were completed to reduce the coefficient of variation for spiny dogfish and snapper.
Biomass estimates (in tonnes) for the target species in the core strata were: giant stargazer, 915 t; red gurnard, 1498 t; red cod, 69 t; snapper, 3633 t; spiny dogfish, 3043 t; and tarakihi, 493 t.
FAR: 2024/06;
ISSN: 1179-5352;
ISBN: 978-1-991120-81-6;
AUTHOR: MacGibbon, D.J.; Walsh, C.; Buckthought, D. Bian, R.;
Title: FAR 2024/05 Review of photo calibration methods for scampi (Metanephrops challengeri) photo surveys
FAR-2024-05-Photo-Calibration-Methods-For-Scampi-Photo-Surveys-4428.pdf (4.8 MB)
 Photo surveys are used to estimate abundance of scampi in New Zealand and provide important information for stock assessments.
Readers identify features in the survey photos as burrows or scampi. A statistical model is applied to produce an estimate of abundance for each survey. The statistical model takes into account differences between readers’ interpretation of features (what looks like a burrow to one reader may not to another) and differences in interpreting features over time (e.g., a reader may become more skilled at interpreting features over time, or technology could improve).
This report provides a review of the statistical model applied to produce an estimate of abundance from scampi photo surveys. The review found no concerns with the model or how it is being applied. Two readers re-read images from recent survey years to test if the adjustment over time has been appropriate. The results of the re-reads supported the model results.
Further work is suggested, including contracting a specialist statistician to provide greater theoretical understanding of the model and assumptions.
AUTHOR: McGregor, V.L.; Holmes, S.J.; Underwood, M.J.;
FAR: 2024/05;
ISSN: 1179-5352;
ISBN: 978-1-991120-75-5;
Title: FAR 2024/04 Red rock lobster (Jasus edwardsii) settlement indices for the 2022–23 fishing year
FAR-2024-04-Settlement-Indices-For-Red-Rock-Lobster-For-202223-4451.pdf (2.7 MB)
The rock lobster fishery is one of New Zealand’s most valuable fisheries.

Understanding larval settlement processes can greatly assist the management of this fishery because they may explain changes in recruitment to the fishery (i.e., reaching legal size), which takes between four and eleven years. This report aims to determine trends in puerulus settlement at selected key sites around New Zealand.

Annual patterns of red rock lobster settlement are described for North Island and South Island coastal areas, based on monthly monitoring of puerulus (the post-larval stage of red rock lobster) settlement collectors.

The monitoring data for 2022–23 are described in this report and used to provide indices of puerulus settlement for 2022–23, and thus extend the time series used to identify annual trends of settlement (since 1979).

Puerulus settlement during the 2022–23 fishing year was above the long-term mean at Gisborne, Castlepoint, and Halfmoon Bay and below the long-term mean at Napie
AUTHOR: Forman, J.S.; McKenzie, A.; Stotter, D.R.;
FAR: 2024/04;
ISBN: 978-1-991120-66-3;
ISSN: 1179-5352;
Title: FAR 2024/03 Relative abundance, size and age structure, and stock status of blue cod in Foveaux Strait in 2023
FAR-2024-03-Foveaux-Strait-BCO5-Blue-Cod-Potting-Survey-February-2023-Results-4449.pdf (2.8 MB)

South Island recreational blue cod fisheries are monitored by Fisheries New Zealand using potting surveys to assess the status of the stocks. The results of the Foveaux Strait surveys are important inputs for full quantitative stock assessments conducted for BCO 5 every five years.

This report describes the results of the random-site blue cod (Parapercis colias) potting survey carried out in Foveaux Strait in February 2023—as well as for three previous surveys (2010, 2014, and 2018). Estimates are provided for population abundance, size structure from fish length, and age structure from otoliths (ear bones collected for ageing), as well as population sex ratio, total mortality, and fishing mortality.

The overall weighted mean length of blue cod in 2023 was 32.0 cm for males and 28.5 cm for females, and mean age was 5.9 years (1–11 years) for males and 6.2 years for females (1–16 years). There were no clear age class modes in 2023 and little evidence of spawning activity during the survey.

The scaled length frequency distributions and mean length of all blue cod were similar for all four surveys, although, in 2

FAR: 2024/03;
ISSN: 1179-5352;
ISBN: 978-1-991120-60-1;
AUTHOR: Beentjes, M.P.; Miller, A.;
Title: FAR 2024/02 The 2023 stock assessment of ling (Genypterus blacodes) off the west coast South Island (LIN 7WC)
FAR-2024-02-2023-Ling-Stock-Assessment-Off-West-Coast-South-Island-LIN7WC-4423.pdf (4.0 MB)
 Ling (Genypterus blacodes) is an important commercial fish species in New Zealand middle depths waters and is caught mainly by bottom trawls, bottom longlines, and increasingly by potting. 
This report summarises the 2023 stock assessment of one of the five main ling stocks managed under the Quota Management System: the ling stock off the west coast of the South Island (LIN 7WC).
A stock assessment model was carried out, based on commercial catches, information from the west coast South Island Tangaroa trawl survey biomass series, the commercial longline standardised catch per unit effort (CPUE) from 1991, and the commercial trawl standardised CPUE from 1997. 
The initial spawning stock biomass (B0) for both the base case model was estimated to be about 62 200 t and stock status in 2023 was estimated as 51% B0. An investigative model run provided a slightly lower initial biomass and stock status in 2023 of 52%.
Five-year projections were done using the base case model, resampling recruitment from the entire range of the model, and assuming future annual catch equal to the average catch in 2020–2022. Projected stock status in 2028 was expected to be 52% of B0. 
The probability that the stock status in 2028 will be above 40% B0 was 97%, and that of being less than 20%, was zero. This assessment was used t
AUTHOR: Mormede, S.; Dunn, A.; Webber, D.N;
FAR: 2024/02;
ISSN: 1179-5352;
ISBN: 978-1-991120-60-1;
Title: FAR 2024/01 Catch-at-age for barracouta (Thyrsites atun) in BAR 5 and gemfish (Rexea solandri) in SKI 3and SKI 7 for the 2021–22 fishing year
FAR-2024-01-Catch-At-Age-For-Barracouta-BAR5-And-Gemfish-SKI3-And-SKI7-2022-4440.pdf (1.6 MB)
Catch-at-age data are important for the stock assessment of fish species because they provide information on the strength and progression of age classes in the stock, including juveniles and fish that are large enough to be taken by commercial fishers. These data include information on fish length and age (from otoliths—the ear bones of fish) collected at sea by observers from the commercial catch.
This report provides analyses of catch-at-age from the bottom trawl fisheries for barracouta (Thyrsites atun, BAR) in BAR 5 (Southland) and for gemfish (Rexea solandri, SKI) in SKI 3 (southeast coast) and SKI 7 (Challenger) for the 2021–22 fishing year. These results are the second of a three-year catch-at-age series for these two species.
Data for the 2021–22 season included few barracouta under 60 cm, indicating either less fishing on smaller (and younger) barracouta, or a poor year class should be expected. Most of the barracouta were aged 2–5 years.
Gemfish from SKI 3 in the 2021–22 fishing year showed a range of fish sizes, with most between 45 and 52 cm, which corresponded to age 2 fish, and also at sizes that corresponded to ages 4–6.
Gemfish from SKI 7 were less variable in length and included some fish under 50 cm, mainly females, which corresponded to ages 0–1. Most of the gemfish in SKI 7 around 50 cm in length co
FAR: 2024/01;
ISSN: 1179-5352;
ISBN: 978-1-991120-59-5;
AUTHOR: Devine, J.A.; Sutton, C.; Hart, A.;
Title: FAR 2023/64 Stock survey of the Foveaux Strait oyster (Ostrea chilensis) fishery (OYU 5), population size structure, and Bonamia exitiosa prevalence, intensity, and disease mortality in February 2023
FAR-2023-64-Foveaux-Strait-Oyster-And-Bonamia-Survey-OYU5-February-2023-4417-combined.pdf (14.6 MB)
 A stock assessment survey of Foveaux Strait oysters (OYU 5) in February 2023 found numbers of commercial-sized, recruit, pre-recruit oysters, and small oysters had decreased by between 44.8% and 52.3% from 2022 numbers. Winter-spring disease mortality is the most likely cause. These decreases cannot be fully explained by fishery and survey data. Summer mortality from Bonamia increased from 5% in 2022 to 9% in 2023. Mostly large oysters died; 70% of oysters are below recruit-size. Spat settlement was high.
AUTHOR: Michael, K.P.; Forman, J.; Smith, L.; Brooks, A.R.; Moss, G.;
FAR: 2023/64;
ISSN: 1179-5352;
ISBN: 978-1-991120-56-4;
Title: AEBR 325 Novel technologies to mitigate the risk of dolphin capture in inshore trawl fisheries: field Implementation and data analysis
AEBR-325-Novel-Technologies-For-Inshore-Fisheries-Dolphin-Capture-Risk-Mitigation-4441-2023.pdf (7.8 MB)
 New Zealand’s Hector’s dolphins are an endangered species. A key threat to their survival is entanglement in fishing gear, including trawl nets. In this study, we report on a field trial where underwater microphones (hydrophones) were fitted to trawling equipment and the echolocation clicks naturally produced by Hector’s dolphins were localised to determine how the dolphins interacted with the trawling equipment as it moved through the water. The hydrophones were protected within custom-built cages to withstand the physical stress associated with being attached to fishing equipment that is dragged along the seabed. The field trial was conducted off the coast of Timaru, New Zealand, in September and October 2022. While the hydrophones recorded dolphin sound underwater, a Fisheries New Zealand observer on the boat also looked out for dolphins.
The protective cages around the hydrophones proved effective and we were able to successfully localise dolphins. Dolphins were localised moving towards the mouth of the fishing net from various approach angles, and, on several occasions, we were able to successfully distinguish multiple dolphins each moving along different paths. Even though we only analysed a subset of the acoustic data from each trawl, dolphin clicks were detected acoustically during trawls on more occasions than the observer on the fishing boat was able to see dolphins. Unfortunately silt from the seabed entered some of
AEBR: 325;
ISBN: 978-1-991120-52-6;
ISSN: 1179-6480;
AUTHOR: Warren, V.E.; Delarue, J.J.-Y.; McEachern, J.; Martin, S.B.; McPherson, C.R.;
Title: FAR 2023/63 Review and summary of the time series of input data available for the assessment of southern blue whiting (Micromesistius australis) stocks up to and including the 2022 season
FAR-2023-63-Southern-Blue-Whiting-Fisheries-Characterisation-Up-To-2022-4422.pdf (8.7 MB)
 This report updates and summarises the observational and research data for southern blue whiting from 1990 to 2022. These data include the time series of relative abundance from acoustic surveys, trawl survey indices, and updated time series of length-at-age and catch-at-age from observer sampling of commercial catch.
FAR: 2023/63;
ISSN: 1179-5352;
ISBN: 978-1-991120-41-0;
AUTHOR: Holmes, S.J.; Bian, R.; Doonan, I.J.;
Title: AEBR 324 Fishery-induced trophic cascades and sea urchin barrens in New Zealand: a review and discussion for management
AEBR-324-Fishery-Induced-Trophic-Cascades-And-Urchin-Barrens-Review-4426-2023.pdf (4.8 MB)
 Sea urchin barrens are sea urchin dominated areas of rocky reef that would normally support healthy kelp forest, but have little or no kelp due to overgrazing by sea urchins.
This review updates our understanding of sea urchin barrens in New Zealand and the role fishing plays in their establishment to date. It also identifies key work required to support management decisions, including collating data on the distribution of urchin barrens, reviewing information required to set catch limits for sea urchin predators, and developing regional management approaches.
We review published scientific literature on sea urchin barrens in New Zealand and the role of fishing in their development.
We also summarise results of a national workshop to support management of sea urchin barrens.
Research based on observations from marine protected areas suggests fishing of sea urchin predators is causing and/or maintaining sea urchin barrens in north-east New Zealand.
The extent of sea urchin barrens and contributing factors in other parts of New Zealand appear to vary, but there are few published studies on this. 
Workshop discussions indicated an urgent need to develop a suite of management options to address sea urchin barrens at regional scales in collaboration with tangata whenua and stakeholders.
AEBR: 324;
ISSN: 1179-6480;
ISBN: 978-1-991120-29-8;
AUTHOR: Doheny, B.; Davis, J.P.; Miller, B.;
Title: FAR 2023/61 Stock assessment of trevally (Pseudocaranx georgianus) for TRE 1 to 2021/22
FAR-2023-61-Trevally-Stock-Assessment-TRE1-To-202122-4432.pdf (4.4 MB)
For the Bay of Plenty base model run current biomass was estimated to be 68.4% B0 (median), with 95% credible interval 46.6–97.7% B0. For all five-year projection scenarios, there was a low probability that the target biomass would decline below the target level of 40% B0. A stock assessment was also attempted for a Ninety Mile Beach/East Northland/Hauraki Gulf stock, but was unsuccessful due to conflicts between the abundance and catch-at-age data.
FAR: 2023/61;
ISSN: 1179-5352;
ISBN: 978-1-991120-25-0;
AUTHOR: McKenzie, A.;
Title: AEBR 323 Habitat use and the impact of multiple stressors on blue cod populations in Canterbury and the Marlborough Sounds
AEBR-323-Habitat-Use-And-Impact-Of-Stressors-On-Blue-Cod-4425-2023.pdf (4.5 MB)
 Changes in blue cod populations off Canterbury and in the Marlborough Sounds has raised concerns about the impact of human stressors on these populations, but the relationship between most stressors and blue cod is unknown.
Information on blue cod abundance was matched with environmental data to understand the habitat characteristics important for blue cod adults and juveniles off three Canterbury sites; Banks Peninsula, Motunau, Kaikōura.
Changes in potential stressors to blue cod habitat were compared with blue cod population status over 20 years at the sites off Canterbury and in the Marlborough Sounds.
Blue cod were associated with areas where the seafloor is rough and complex (e.g., reef systems), where structural habitat was provided by plants and animals, and in areas with higher water clarity and lower temperature.
Blue cod population status was related to stressors from land use (e.g., coastal water quality), and increasing water temperatures in most locations, although the intensity of these stressors has varied substantially over time and among locations.
This information provides guidance on the scale and focus for future research and potential management opportunities to limit these stressors and ensure sustainability of the blue cod fishery.
AEBR: 323;
ISSN: 1179-6480;
ISBN: 978-1-991120-23-6;
AUTHOR: Brough, T.E.; Leunissen, E.M.; Beentjes, M.;
Title: FAR 2023/62 Pāua harvest estimates by land-based amateur fishers—Kaikōura Marine Area in 2023
FAR-2023-62-Paua-Harvest-Estimates-From-Land-Based-Amateur-Fishers-Kaikoura-2023-4438.pdf (2.7 MB)
This report describes the survey estimates for blackfoot pāua landed by amateur fishers from land-based access points in the Kaikōura Marine Area and Oaro during a two-month open season from 15 April 2023. This was the second survey conducted to estimate amateur harvest of pāua in the Kaikōura Marine Area and the first to provide cumulative harvest estimates weekly during the open season. Harvest numbers were estimated for rock lobster, yellowfoot pāua, and kina.
FAR: 2023/62;
ISSN: 1179-5352;
ISBN: 978-1-991120-26-7;
AUTHOR: Holdsworth, J.C.; Curtis, S.; Neubauer, P.;
Title: FAR 2023/60 Biomass survey and condition index for kina (Evechinus chloroticus) in SUR 7A
FAR-2023-60-Kina-Biomass-Survey-And-Condition-Index-SUR7A-4433.pdf (1.2 MB)
This report presents the results of a field survey made in December 2022 to estimate the abundance of kina in Tory Channel, Marlborough Sounds (SUR 7A). Kina densities were determined along with roe biomass from dive and camera transects, with estimates of abundance utilising high resolution bathymetry data. Total biomass of kina in the survey area was estimated to be 595 t, with a CV of 19%; the biomass of kina roe was estimated to be 62.9 t, most of which was in the highest quality category.
FAR: 2023/60;
ISSN: 1179-5352;
ISBN: 978-1-991120-24-3;
AUTHOR: Anderson, O.F.; Olsen, L.; Marriott, P.; Stead, J.; Hayden, M.; Olmedo-Rojas, P.;
Title: FAR 2023/59 Further development of models for arrow squid in New Zealand waters
FAR-2023-59-Further-Development-Of-Models-For-Arrow-Squid-4408.pdf (8.0 MB)
This report summarises population models for arrow squid in the Subantarctic. The models captured the main biological processes adequately. Recruitment estimates were robust to model assumptions and structure. However, absolute estimates of biomass were highly uncertain. The potential for in-season management was tested. Proxies that could be used to compare current relative exploitation rates with past conditions were also investigated; these could be used for hindcasting.
FAR: 2023/59;
ISSN: 1179-5352;
ISBN: 978-1-991120-22-9;
AUTHOR: Mormede, S.; Dunn, A.; Webber, D.N.;
Title: FAR 2023/58 The 2022 stock assessment for scampi (Metanephrops challengeri) in the Bay of Plenty (SCI 1) and Hawke Bay-Wairarapa (SCI 2) 1990–2022
FAR-2023-58-Scampi-2022-Stock-Assessment-For-SCI1-And-SCI2-To-2022-4348.pdf (7.5 MB)
Fisheries stock assessments were undertaken for SCI 1 and SCI 2. The SCI 1 assessment was rejected by the Fisheries New Zealand Deepwater Working Group due to sensitivity to the trawl survey catchability prior. The SCI 2 assessment was accepted, but with a lower quality rating due to unresolved conflicts in data inputs. For SCI 2 current status in 2022 was estimated to be 56% B0 and likely within 47–66% B0. Projections were not carried out with either assessment.
FAR: 2023/58;
ISBN: 978-1-991120-21-2;
ISSN: 1179-5352;
AUTHOR: McGregor, V.L.;
Title: FAR 2023/57 Climate impacts on fished populations. Part 2: Effects of climate and environmental variability on fishery stock assessment accuracy
FAR-2023-57-Climate-Impacts-On-Fished-Populations-Part2-Stock-Assessment-4178.pdf (9.5 MB)
 This study used a model of individual eco-physiological response to environmental and climate factors to derive population level outcomes of fish stocks. These simulations were used to investigate how fisheries stock assessments are influenced by climate and bottom-up variability in production parameters. The assessments generally provided unbiased estimates of stock status even though there were annual and decadal fluctuations in all production-related parameters.
AUTHOR: Neubauer, P. ; A’mar, T. ; Dunn, M.;
FAR: 2023/57;
ISSN: 1179-5352;
ISBN: 978-1-991120-15-1;
Title: FAR 2023/56 Climate impacts on fished populations. Part 1: Simulating bottom-up, physiological, and fishery-induced changes in production potential
FAR-2023-56-Climate-Impacts-On-Fished-Populations-Part1-4177.pdf (5.1 MB)
This study assessed the influence of climate on fish stocks by developing a model of individual eco-physiological response to environmental factors. The model was used to derive population level outcomes, and to investigate the response of fish stocks to climate variation at different levels of fishing intensity. The findings suggest that productivity parameters need to be considered in combination with density-dependent responses to determine the impact of climate change on fish stocks.
AUTHOR: Neubauer, P. ; A’mar, T. ; Dunn, M.;
ISSN: 1179-5352;
ISBN: 978-1-991120-14-4;
FAR: 2023/56;
Title: FAR 2023/55 A review of the Foveaux Strait oyster (OYU 5) stock assessment model and recommendations for future development
FAR-2023-55-Foveaux-Strait-Oyster-OYU5-Stock-Assessment-Review-And-Recommendations-4345.pdf (2.2 MB)
The Foveaux Strait oyster (OYU 5) stock assessment model was reviewed. Development of a disease sub-model to provide projections of future disease mortality will greatly improve assessments. B0 and stock reference points may be overestimated. Conceptual models of climatic, environmental, habitat, disease, and biological drivers of oyster production highlight several knowledge gaps. An understanding of disease processes and new time series data will underpin better stock projections.
FAR: 2023/55;
ISBN: 1179-5352;
ISSN: 978-1-991120-09-0;
AUTHOR: Michael, K.P.; Doonan, I.J.; Lane, H.S.; Datta, S.;
Title: FAR 2023/54 Drivers of long-term change in the Foveaux Strait oyster (Ostrea chilensis) fishery (OYU 5)
FAR-2023-54-Drivers-Of-Long-Term-Change-Foveaux-Strait-Oysters-OYU5-4346.pdf (4.5 MB)
Drivers of long-term change in the Foveaux Strait oyster fishery (OYU 5) including the effects of disease and dredging essential oyster habitat are investigated. High densities of oysters are determined by recruitment and mortality from Bonamia exitiosa. Regular recruitment to the population shows productivity of the oyster fishery is high and is not likely to have changed. Oyster factors, co-infections with other pathogens, and climatic variables may affect oyster mortality and recruitment.
FAR: 2023/54;
ISSN: 1179-5352;
ISBN: 978-1-991120-08-3;
AUTHOR: Michael, K.P.;
Title: FAR 2023/53 Stock assessment research in 2023 for silver warehou in SWA 3 and SWA 4
FAR-2023-53-Silver-Warehou-Stock-Assessment-Research-In-2023-SWA3-And-SWA4-4406.pdf (5.7 MB)
The silver warehou stock assessment conducted in 2023 is described. The assessment was ultimately rejected by the Fisheries New Zealand Deepwater Working Group. The data inputs and model assumptions are described. The main problems encountered, concerning stock structure, CPUE, age data, and model specifications, and their possible solutions, are discussed.
FAR: 2023/53;
ISBN: 978-1-991120-04-5;
ISSN: 1179-5352;
AUTHOR: Dunn, M.R.; McGregor, V.L.;
Title: AEBR 322 Desktop update of estimation of seabird cryptic mortality in trawls, via warp and net captures in the New Zealand domestic fleet using standard mitigation
AEBR-322-Desktop-Update-Estimation-Of-Seabird-Cryptic-Mortality-In-Domestic-Trawl-Fisheries-2023-4323.pdf (1.0 MB)
The study investigates cryptic mortality (i.e., deaths that are not observed) of seabirds in New Zealand’s trawl fisheries, separately for net captures and warp cable strikes. For net capture-related mortality, the results suggest that, on average, mortality was 2.5 times higher than when only based on observed captures. For warp strikes, estimates varied based on data sources, highlighting the need for tailored data collection due to uncertainties and sparseness in the current dataset.
AEBR: 322;
ISSN: 1179-6480;
ISBN: 978-1-991120-02-1;
AUTHOR: Meyer, S.;
Title: AEBR 321 Updated fisheries risk assessment framework for seabirds in the Southern Hemisphere
AEBR-321-Updated-Risk-Assessment-Framework-For-Southern-Hemisphere-Seabirds-2023-4407.pdf (6.1 MB)
The Spatially Explicit Fisheries Risk Assessment framework has recently been updated and applied to assess the fisheries risk to seabird populations within the New Zealand EEZ. In the current report, the approach is applied to seabirds globally in the southern hemisphere. Catchabilities were estimated from New Zealand captures. Then global fishing effort and species distributions were collated and used to assess the risk to seabirds from predicted fisheries captures throughout their range.
AEBR: 321;
ISSN: 1179-6480;
ISBN: 978-1-991087-93-5;
AUTHOR: Edwards, C.T.T.; Peatman, T.; Roberts, J.O.; Devine, J.A.; Hoyle, S.D.;
Title: FAR 2023/52 Recruitment of freshwater eels, 1995–2022
FAR-2023-52-Recruitment-Of-Freshwater-Eels-1995-To-2022-4434.pdf (9.3 MB)
Data on elver catches of longfin and shortfin eels from hydroelectric barriers were collected during the 2018–19 to 2021–22 seasons. Catches contained moderate shortfin numbers, but moderate-high longfin numbers. Combined recruitment indices from all sites and seasons showed that recruitment of both species is variable within and between sites but remained stable, consistent with previous studies, indicating that recruitment of elvers has remained stable within the time frames of the datasets.
FAR: 2023/52;
ISSN: 1179-5352;
ISBN: 978-1-991087-98-0;
AUTHOR: Crow, S.K.; Lambert, P.W.; Egan, E.M.; Bowman, E.;
Title: FAR 2023/51 Descriptive analysis of ling off the west coast South Island (LIN 7WC) up to 2021–22 and inputs for the 2023 stock assessment
FAR-2023-51-Descriptive-Analysis-Of-Ling-In-LIN7WC-To-202122-And-2023-Assessment-Inputs-4403.pdf (19.7 MB)
This report summarises the ling stock off the west coast South Island (LIN 7WC) and fishery. It describes the spatial structure of the stock, biological parameters, and trawl and longline standardised catch per unit effort (CPUE). Statistical Area 032 was reassigned to LIN 7WC based on the continuity of catch locations. The trawl and longline fishery CPUE and survey biomass showed similar patterns from 2000, with a decline from 2012. All three indices were considered in the stock assessment.
FAR: 2023/51;
ISBN: 978-1-991087-97-3;
ISSN: 1179-5352;
AUTHOR: Mormede, S.; Dunn, A.; Webber, D.N.;
Title: FAR 2023/50 Towards an assessment of arrow squid in New Zealand waters
FAR-2023-50-Towards-An-Assessment-Of-Arrow-Squid-In-New-Zealand-Waters-4391.pdf (12.5 MB)
This report investigated the spatial and temporal structure of arrow squid (Nototodarus sloanii and N. gouldi) in New Zealand. Five potential stocks were defined. Estimates of growth rate were consistent with previous estimates. Spatial-temporal standardised CPUE fortnightly indices were developed and could be predicted relatively well by environmental variables. Preliminary population models showed recruitment was well estimated but initial biomass was highly uncertain.
FAR: 2023/50;
ISSN: 1179-5352;
ISBN: 978-1-991087-95-9;
AUTHOR: Mormede, S.; Dunn, A.;