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 to inform Fisheries New Zealand’s management of this ling stock.

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 corresponded to age 2; this was a strong cohort, particularly for males. Females were generally larger (and older) than males in the bottom trawl catch, with a strong mode at ages 5–8 for the females.

The aim of this project is to provide a pathway that enables New Zealand to implement the 2013 WS

methodology for drained Organic Soils. The objectives were to:

1 review spatial data to inform the current and 1990 extent of Organic Soils, and review classification

approaches and their implications

2 review approaches to estimating current and 1990 activity data for Organic Soil areas, including

nutrient status, drainage depth, and land-use class

3 review IPCC emission factors and existing greenhouse gas measurement studies from Organic Soils

in New Zealand, and examine the ability to derive New Zealand / region-specific emission factors

based on these data

4 provide recommendations to implement the 2013 WS at a minimum level and make recommendations

for where future research should be prioritised to improve emission estimates for drained Organic

Soils in New Zealand on the basis of the highest sources of emissions and/or the highest sources of

uncertainty

This report has two main objectives.

1) To present a new approach to documenting and predicting people’s willingness to manage invasive species and designing
appropriate public engagement strategies.

2) To present new simulation tools for modelling.

This Sustainable Land Management and Climate Change (SLMACC) project “Quantifying climate change adaptation plans” uses kiwifruit and avocado as exemplars of high-value crops. It aims to predict the performance of horticultural crops under climate change, to quantify growers’ exposure to climate change, and to model how this exposure is affected by adaptations designed to ameliorate climate impacts.

The impact of floods on the primary sector was first assessed nationally and then for the Awanui River Catchment in Northland. The analyses focused on the impacts of flooding on the primary sector, including changes in land uses as an adaption response to floods with climate change and subsequent changes in economic and environmental indicators. The specific objectives of the analysis are to:

1 quantify New Zealand’s primary sector exposure to flood hazards.

2 quantify the primary sector’s exposure and financial losses from floods in one catchment – the Awanui catchment.

3 analyse the impacts of flooding on land-use change and economic and environmental indicators.

4 evaluate economic and social welfare changes from floods-induced land-use change.