Fisheries Management

Assessing the biology and connectivity of deep-water finfish on Australia’s east coast and the impact of fleet dynamics

Project number: 2022-152

Project Status:

Current

Budget expenditure: $433,228.00

Principal Investigator: Matthew McMillan

Organisation: Department of Primary Industries (QLD)

Project start/end date: 30 Jun 2023 - 19 Dec 2025

Contact:

FRDC

Need

Deep-water finfish are an increasingly important fisheries resource on Australia's east coast that has been subjected to recent and rapid growth in fishing pressure across commercial, recreational, and charter sectors. Drivers of increased targeting of deep-water species likely include depletion of inshore stocks leading to effort shifts to deeper areas, advances in technology facilitating more effective targeting of deep-water species and changing market dynamics leading to increased profitability. However, sustainable management of deep-water finfish stocks requires species-specific information on fundamental life history characteristics and stock structure to inform evidence-based management that is currently lacking.

Deep-water species are often characterised by slow growth, late maturity, and clustered distributions around pockets of suitable habitat that leave them vulnerable to overfishing. It is necessary to determine how such traits and connectivity among populations affect the sustainability of fisheries for key deep-water species on Australia's east coast. Management of deep-water species is also complicated by cross-jurisdictional distributions including Queensland, New South Wales, and Commonwealth managed fisheries.

Currently, due to the lack of fundamental biological information, key deep-water species are managed using basic harvest strategies set to trigger enhanced management and scientific focus when such need arises, which is now occurring. For example, the 2021 commercial harvest of Bar Cod (Epinephelus ergastularius) in Queensland exceeded double the mean harvest from 2011-2015, triggering a requirement for the first stock assessment of this species. Anecdotally, recreational catches in Queensland of other key species including Flametail Snapper (Etelis coruscans) and Goldband Snapper (Pristipomoides multidens) have substantially increased in recent years, with the latter given priority status for future stock assessment. New South Wales DPI has indicated a particular need for research focus on Bass groper (Polyprion americanus) and Hapuku (Polyprion oxygeneios) due to the complete lack of biological information required for fisheries management of these species, both of which are now quota managed. Recreational fishing effort is important to quantify because this sector has come to dominate the deep-water fishery in some areas where commercial fishing effort is sparse. Changing fleet dynamics and the uptake of technological advances in fishing gear have also increased fishing power for deep-water species in ways that are poorly understood.

This project aims to address these issues with a cross-jurisdictional collaboration between Qld DAF, NSW DPI, and AFMA supported by the University of Queensland providing fundamental information on the biology and population connectivity of key deep-water species. Project staff are well placed to leverage their existing networks and will also build new relationships with stakeholders throughout the deep-water fishery to pursue sample collection from all available sources including commercial fishers, processors, and recreational and charter fishers. Archived samples and targeted fishery-independent sampling will also be employed to secure sufficient samples to provide confident estimates on life history parameters and population connectivity to inform stock assessment. Additionally, we aim to develop novel methods to improve recreational reporting of deep-water catches and improve estimates of fishing power effects on catches of deep-water finfish.

Objectives

1. Describe the life history characteristics of key deep-water species, e.g., Bar Cod, Flametail Snapper, and Goldband Snapper

2. Understand the stock structure and connectivity of deep-water species in Queensland and New South Wales

3. Investigate and implement novel methods for improving recreational catch reporting of deep-water species

4. Improve estimates of fishing power in the deep-water line fishery by reviewing (as opposed to trialling) historic and current fishing technologies

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PROJECT NUMBER • 2022-152

PROJECT STATUS:

CURRENT

Assessing the biology and connectivity of deep-water finfish on Australia’s east coast and the impact of fleet dynamics

1. Describe the life history characteristics of key deep-water species, e.g., Bar Cod, Flametail Snapper, and Goldband Snapper

ORGANISATION:

Department of Primary Industries (QLD)

PROJECT NUMBER • 2017-100

PROJECT STATUS:

COMPLETED

Status of Australian Fish Stocks (SAFS) reports 2018, and further development of the SAFS production and dissemination system

1. Continue to develop a set of robust and consistent national stock status reports and a strong sense of report ownership by jurisdictions

ORGANISATION:

Fisheries Research and Development Corporation (FRDC)

PROJECT NUMBER • 2015-034

PROJECT STATUS:

COMPLETED

Status of Australian Fish Stocks (SAFS) reports 2016, and further development of the SAFS production and dissemination system

1. Continue to develop a set of robust and consistent national stock status reports and a strong sense of report ownership by jurisdictions

ORGANISATION:

Fisheries Research and Development Corporation (FRDC)

Developing a Kimberley Aboriginal Mud Crab Fishery

Project number: 2022-138

Project Status:

Current

Budget expenditure: $736,621.00

Principal Investigator: Danielle Johnston

Organisation: Department of Primary Industries and Regional Development (DPIRD) WA

Project start/end date: 30 Jun 2023 - 29 Jun 2026

Contact:

FRDC

Need

The commercial mud crab fishery in WA has yet to develop to its full potential due to a limited understanding of the mud crab resource, a lack of capacity, isolation from markets, and the logistical constraints of the remote and challenging environment of the Kimberley region. The development of Aboriginal fisheries is a high priority for DPIRD and FRDC, and this proposal to promote the Kimberley Aboriginal mud crab fishery aligns directly with this strategic objective. The project also addresses key priorities adopted by the WARAC and WAFIC, such as the development of Aboriginal and under-utilised fisheries in WA. The project represents a 2-way capacity building opportunity between Aboriginal people and DPIRD staff, with data generated during this project on species biology, spatial distribution and relative abundance informing future stock assessments to improve certainty around the sustainability of the WA mud crab resource. Specifically, the project will:

• use applicable and demonstrative scientific outcomes to develop participative management approaches for the Kimberley mud crab fishery that aim for fairness through prescribed fishery controls (trap allocations, harvest
strategies etc.) (Fair and secure access to aquatic resources).

• increase learning and sharing between Traditional Owners and DPIRD through identifying, documenting and promoting Aboriginal fisheries management systems and fishing practices. Identify a suitable working model for the
Indigenous mud crab fishery in the Kimberley which is culturally informed and reflects the relative abundance of the available mud crab resource. (Best practises and production systems).

• improve connection of Traditional Owners in the Kimberley region with mud crab fishing initiatives that promote economic opportunities (Growth for enduring prosperity).

• strengthen the association across Traditional Owner groups, commercial and recreational mud crab fishers, FRDC and DPIRD to maximise cooperative partnerships that promote greater inclusiveness, creative thought and solution
seeking to support the economic viability of the Kimberley mud crab fishery (A culture that is inclusive and forward thinking).

• promote relationships and communications between stakeholders and the Kimberley community through transparent decision-making tools and best practice fisheries management that ensures a fair distribution of economic and
societal benefits from the Kimberley mud crab resource (Community trust, respect and value).

Objectives

1. Determine the biology and distribution of mud crab species (Scylla serrata and S. olivacea) in King Sound and Cambridge Gulf areas of the Kimberley region of Western Australia.

2. Determine the relative abundance of mud crabs within and between sites in King Sound and Cambridge Gulf across different habitat types (mangrove creeks vs channels vs mud flats) and tidal cycles (spring vs neap).

3. Transfer of mud crab commercial fishing methods, western scientific techniques, and traditional knowledge between Traditional Owners and DPIRD for future commercial application, through collaborative research surveys, DPIRD-led On-Country workshops and a related DPIRD-CRCNA Aboriginal Fishing and Aquaculture project (2022-24).

Developing spatial based assessment methodologies and tools for small scale dive fisheries: Case study of the Tasmanian Commercial Dive Fishery

Project number: 2022-039

Project Status:

Current

Budget expenditure: $298,378.33

Principal Investigator: John P. Keane

Organisation: Institute for Marine and Antarctic Studies (IMAS) Hobart

Project start/end date: 29 Apr 2023 - 30 Mar 2026

Contact:

FRDC

Need

The Tasmanian Commercial Dive Fishery (TCDF) is transitioning from a fishery with minimal controls on catch with no annual assessment, to a carefully managed fishery with annual robust fishery assessments. Two of the three key species Shortspined Sea Urchin (Heliocidaris erythrogramma) and Wavy Periwinkle (Lunella undulata), have similar life histories to abalone, while the third – Longspined Sea Urchin (Centrostephanus rodgersii), has an intermediate life history. All three species have a time-series of catch and effort data, and some level of biological data, and thus don’t fall into the class of data-poor fisheries. However, just as for haliotid fisheries, all the complexities identified by Orensanz et al (1995) for S-Fisheries (small-scale, spatial structured, sedentary target species) apply here, meaning that integrated assessment models assuming Dynamic Pool should not be used. Instead, Empirical Harvest Strategies based on standardised catch rates are the most appropriate approach to underpin annual assessments and determination of stock status. Given the similarities between these species and abalone (life history, habitat, fishing practices), it is desirable to utilise the considerable investment in research on data collection and assessment methods in that fishery. This project will therefore attempt to adopt and adapt ground-breaking research on Abalone, including utilization of high-resolution spatial data from GPS and depth data loggers, as a short-cut to worlds best practices in the TCDF.

Consideration of stock status for the TCDF species to date has been on the basis of graphical inspection of crude catch rates. As Empirical Harvest Strategies rely heavily on robust catch rate metrics, adopting a model for standardizing catch rates is a critical step for the TCDF fisheries. While there are a diversity of philosophies around catch rate standardization, choosing the optimal standardization model is only part of the challenge. The key challenge for the three key TCDF species are that catch is spatially and temporally fragmented. Both urchin species are highly seasonal, and Shortspined Sea Urchin and Wavy Periwinkle fisheries are spatially discrete with a few high catch areas, and a larger proportion of spatially and temporally disparate low productivity fishing grounds. Similarly, catch is largely landed by a small number of highly active participants, with a larger number of primarily part-time fisheries. This fragmented nature (time, space, people) of the dataset creates challenges for applying standardisation models to establish a robust time-series. Primarily this manifests as highly volatile time-series, that can flip above or below Reference Points over consecutive years. In some fisheries, this challenge is addressed by fitting a multi-year running mean through catch rates, essentially smoothing the trend. While this might have the desired effect of removing hyper-variability in catch rates, it will slow action required as the stocks decline, as well slow catch increases under rebuilding. Preferably, we will instead use environmental variables, quantify fisher experience and make use of fine-scale location data on fishing activity in our catch rate standardization methods.

An additional complication in the Tasmanian Commercial Dive fishery is mixed species fishing. This feature is also present in a sub-set of assessment areas within the Tasmanian Abalone fishery where H. rubra and H. laevigata co-occur, as well as in the Central and Western Zone abalone fisheries in South Australia. Developing a clear catch rate signal in these mixed species fisheries is challenging and an optimal solution has not yet been found, although spatial and depth information most likely will enable differentiation of fishing grounds across species. Through this project we will engage with South Australia specifically to collaborate on logger based approaches to improve assessment of mixed species fishing regions.

As with abalone fisheries, TCDA divers are able to modify their in-water fishing behaviour (swim faster and further) to achieve desired daily catches which has the effect of masking decline in abundance. However, this is not the only form of hyperstability expected in the TCDA fisheries. The highly fragmented stock structure and diver experience are likely to interact to create a second form of hyperstability more common in emerging fisheries, and that is serial depletion, or at least serial fishing of discrete patches. This latter form of hyperstability occurs when more experienced divers with greater knowledge are able to move when more accessible patches become over-exploited.

Local scale depletion is addressed by the establishment of size limits for Wavy Periwinkle and the Shortspined Sea Urchin. Robust size limits have recently been adjusted for Wavy Periwinkle (increase from 30 to 45 mm; FRDC 2011-024) and Shortspined Sea Urchin (increase from 60 to 75 mm FRDC 2017-033); No size limit is intended to be set for range-extending Longspined Sea Urchin, as the objective in this fishery continues to be to achieve localised depletion.

From the 2022/2023 season diver GPS and depth loggers will be compulsory to collect detailed spatial information about the fishery. Several key divers have been using dataloggers for the past eight years, providing a valuable time-series from the more experienced TCDF fishers. The availability of such data creates a new opportunity and leads to the key aim of this project, to develop methodologies and tools to incorporate the detailed spatial catch data into formal stock assessment and harvest strategies. In doing so, methods to facilitate the accurate standardisation of historical logbook data to facilitate transition into logger data to preserving the continuum of the time series is required. The development of reliable fishery dependent assessment metrics is essential in these smaller fisheries where there is no scope for cost-prohibitive fishery independent surveys.

In summary, this project is needed to develop strategies to produce robust standardized catch rate trends, that can be utilized in an Empirical Harvest Strategy. Spatial based Catch Per Unit Effort (CPUE) measures and spatial performance indicators and indices of hyperstability will be critical to facilitate the creation of appropriate stock assessment and harvest strategies for small scale dive fisheries, including smaller haliotid fisheries.

Objectives

1. Determine optimal methods for production of time-series trends by standardisation of spatially and temporally fragmented fishing events.

2. Contrast suitability of effort measured as dive time vs area fished as the basis for catch rates (catch/effort) for highly spatially discrete target species.

3. Develop a strategy for determining reference periods and reference points for use in an Empirical Harvest Strategy.

4. Adapt the Tasmanian abalone Empirical Harvest Strategy for use in the TCDF.

5. Test for the presence of hyperstability in catch rates within the TCDF, and where appropriate, develop options to modify Empirical Harvest Strategy Control Rule settings accordingly.

6. Identify additional performance measures for inclusion in the Empirical Harvest Strategy

7. To build the capacity and capability of key stakeholders to contribute to the development of Tasmanian Commercial Dive Fishery (TCDF) assessment methodology and harvest strategy, facilitate succession planning, and lay a foundation for dive fishery assessment development nationally.

Fisheries Management

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