This project will build on the 2022 FRDC National Workshop on Shark Depredation (project number 2021-038) and have four complementary phases through: (1) a detailed review of the peer-reviewed and grey literature to identify and assess the efficacy of the most recently developed mitigation methods, (2) a survey of the scientific community and fishing-industry stakeholders (i.e. fishers, industry representatives, managers) to identify lesser known methods developed and/or used by fishers, (3) a series of workshops to identify the most promising approaches for mitigating depredation and plan the design of field trials, with a stop/go point occurring at the end of this phase based on whether suitable methods are found, and if so, (4) a robust experimental trial of the most promising mitigation method(s) to assess their effectiveness at reducing shark depredation. Phase 4 would be dependent on whether suitable methods can be identified through Phases 1–3. Stakeholder involvement and outreach will be a critical part of this project across all phases. The findings of this project will be widely disseminated via presentations to fishing clubs and industry members, written articles in the FRDC and fishing magazines, a final project report and subsequent peer reviewed publications. All off these outreach activities will be conducted in collaboration with the FRDC Extension Officer network. This will ensure broad adoption of the identified depredation mitigation measure(s).

Target species of Tasmanian scalefish fisheries (TSF) remain difficult to assess and manage due to the wide range of species (> 20 species) and variety of both commercial and recreational fisheries methods. TSF are currently assessed using commercial catch and effort data as well as age and length information. However, some key TSF species landings are increasingly greater in the recreational sector, with a comparatively low commercial catch. Therefore, due to the absence of regular and robust CPUE data, innovative fishery independent data collection programs are required to routinely monitor TSF species and provide adequate data for stock assessment models. This project will review and collate data from previous studies to design and test strategic and cost-effective novel fishery-independent survey methods that collect population dynamics data for a suite of key scalefish fisheries species, across both environmental and fishing intensity gradients in Tasmania. Outcomes will improve stock assessment methods by providing new and additional data for data-poor and undefined species, and, if proven cost-effective, establish an ongoing, long-term fishery-independent monitoring program to enhance the sustainability of TSF. We will collate historical data on Tasmanian scalefish abundance, biomass, distribution, and length-frequencies collected in previous research projects and collect and compare new data to fill current knowledge gaps about localised population depletion and population dynamics across different habitats. Many of the popular commercial and recreational scalefish fisheries are increasingly of concern, with southern sand flathead, southern garfish, and bastard and striped trumpeters all assessed as depleted in the most recent (2020/21) Tasmanian stock assessment (Fraser et al 2022), while others (such as flounder - Pleuronectidae family, longsnout boarfish, and barracouta) were assessed as undefined due to lack of available data for these species. Our results will better inform data-poor stock assessment approaches and will have implications for fisheries managers making critical management decisions for depleted, depleting, and undefined Tasmanian scalefish fisheries species.