Scoping current and future genetic tools, their limitations and their applications for wild fisheries management

The overarching goal of this project was to prepare a document that summarises past, present and emerging ways in which research using genetic technology can assist the Australian fishing industry to maintain productive and sustainable harvests. The project achieved the following specific objectives: 1. Documented existing and prospective biotechnologies and genetic analysis tools that are relevant to wild fisheries management, and their availability and application at a national and international level; 2. Documented the FRDC’s past and current investment in biotechnology and genetic tools used in wild fisheries management research; 3. Documented the different biotechnology and genetic tools that are being used in wild fisheries management research in Australia, and the nature and location of key research groups; 4. Described what management question each tool has been used for (e.g. stock structure, biomass estimation, product provenance, disease monitoring); 5. Identified those tools and approaches (existing and future) most likely to deliver significant advances in fisheries management; 6. Identified the potential for collaborations which could improve the focus and impact of work in this area

Torres Strait Finfish Fishery: Spanish Mackerel stock assessment, with data to June 2021. Year one report.

Spanish mackerel, Scomberomorus commerson, sustain an important finfish line fishery within the Torres Strait and are managed as a single stock. In these waters the species have been recorded to live for up to 13 years, weigh in excess of 20 kg and mature from two years of age. The Australian Fisheries Management Authority (AFMA) commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This was to monitor biomass estimates that were close to the 20 percent limit reference point for declaring an overfished stock. Across analyses of different fish natural mortality and harvest, the median estimated spawning biomass of Spanish mackerel in 2020 was 29 percent of unfished estimates at the start of the fishery in 1940. The low biomass result was due to the high harvests between 1980 and 2006 and the downturn in Spanish mackerel catch rates 2010–2019. The 2022–2023 recommended biological catch (RBC) of Spanish mackerel for all fishing sectors in the Torres Strait was 95 t based on the median forecast estimate (Table 1). This RBC was forecast to build Spanish mackerel towards a target biomass of 48% within 12 years, and have less than 10% risk of reducing to the 20% biomass limit reference point. The assessment work also initiated the first comparison of the packaged stock assessment software stock synthesis (SS), which was used for assessing Australian east coast and Gulf of Carpentaria Spanish mackerel. The SS estimate of spawning biomass ratio in 2020 was similar compared against the current model developed by the Department of Agriculture and Fisheries and reported herein. SS performance and results will be further tested in years two and three of this AFMA project, noting that future provision of a streamlined stock assessment is to transition to stock synthesis after TSFFRAG review

Torres Strait Finfish Fishery: Spanish mackerel stock assessment, with data to June 2022. Year Two Report.

The Torres Strait Spanish mackerel fishery commenced in 1941. The fishery for Spanish mackerel is by line fishing only and managed as a single stock. Spanish mackerel are important to the Torres Strait people and fishing culture. They are an economic and traditional food source. The Australian Fisheries Management Authority commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This is to support quota management and to monitor spawning biomass estimates. This stock assessment, the year-two project report, analysed data up to June 2022. The assessment was overseen by the Torres Strait Finfish Fishery Resource Assessment Group (TSFFRAG). Across analyses, the median estimated spawning biomass of Spanish mackerel in the 2021–2022 financial year (labelled the 2022 fishing year) was 31 percent of unfished estimates at the start of the fishery in 1941

Torres Strait Finfish Fishery: Spanish mackerel stock assessment, with data to June 2023. Year Three Report.

The Torres Strait Spanish mackerel fishery commenced in 1941. The fishery for Spanish mackerel is by line fishing only and managed as a single stock. Spanish mackerel are important to the Torres Strait people and fishing culture. They are an economic and traditional food source. The Australian Fisheries Management Authority commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This was to support quota management and to monitor spawning biomass estimates. This stock assessment analysed data up to June 2023. The assessment was overseen by the Torres Strait Finfish Fishery Resource Assessment Group (TSFFRAG). Across analyses, the median estimated spawning biomass of Spanish mackerel in the 2022–2023 financial year (labelled the 2023 fishing year) was 41 percent of unfished estimates at the start of the fishery in 1941

Torres Strait Finfish Fishery: Spanish Mackerel stock assessment, with data to June 2021. Year one report.

Spanish mackerel, Scomberomorus commerson, sustain an important finfish line fishery within the Torres Strait and are managed as a single stock. In these waters the species have been recorded to live for up to 13 years, weigh in excess of 20 kg and mature from two years of age. The Australian Fisheries Management Authority (AFMA) commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This was to monitor biomass estimates that were close to the 20 percent limit reference point for declaring an overfished stock. Across analyses of different fish natural mortality and harvest, the median estimated spawning biomass of Spanish mackerel in 2020 was 29 percent of unfished estimates at the start of the fishery in 1940. The low biomass result was due to the high harvests between 1980 and 2006 and the downturn in Spanish mackerel catch rates 2010–2019. The 2022–2023 recommended biological catch (RBC) of Spanish mackerel for all fishing sectors in the Torres Strait was 95 t based on the median forecast estimate (Table 1). This RBC was forecast to build Spanish mackerel towards a target biomass of 48% within 12 years, and have less than 10% risk of reducing to the 20% biomass limit reference point. The assessment work also initiated the first comparison of the packaged stock assessment software stock synthesis (SS), which was used for assessing Australian east coast and Gulf of Carpentaria Spanish mackerel. The SS estimate of spawning biomass ratio in 2020 was similar compared against the current model developed by the Department of Agriculture and Fisheries and reported herein. SS performance and results will be further tested in years two and three of this AFMA project, noting that future provision of a streamlined stock assessment is to transition to stock synthesis after TSFFRAG review

Sustaining productivity of tropical red snappers using new monitoring and reference points

OBJECTIVES: 1. Analyse current monitoring and logbook data sets, as well as survey and other information,to establish whether these data provide sufficient power to develop critical indicators of fishery performance. 2. Provide a risk analysis that examines the use of age structure and catch rate information for development of critical indicators, and response rules for those criteria, in the absence of other fishery information. 3. Develop a monitoring program that uses commercial vessels from the fishery to provide independent data

Development of a trawl efficiency device (TED) for Australian prawn fisheries. II. Field evaluations of the AusTED

Concerns about Australian bycatch issues lead to the development of an innovative bycatch reduction system designed for Australian trawling conditions. The system, known as the Australian trawl efficiency device (AusTED), incorporates features of previous TEDs, but includes a flexible grid. The AusTED was tested at five selected locations, which ranged from shallow, estuarine, mud-bottom sites to deep-water, oceanic, sand-bottom sites. No significant differences were observed in prawn catch rates between control and AusTED equipped nets. Sea turtles and large stingrays were excluded from the AusTED equipped net and non-commercial bycatch was significantly reduced at most sites trawled. The AusTED system has the potential to be developed to suit the bycatch exclusion requirements of prawn trawl fisheries around Australia. Its acceptance by the fishing industry will depend upon the minimisation of prawn losses