22 results

The biology and ecology of the blacklip abalone with reference to the juvenile stage between post-planktonic settlement and recruitment to the fishery

Project number: 1982-043
Project Status:
Completed
Budget expenditure: $0.00
Organisation: University of Tasmania (UTAS)
Project start/end date: 28 Jul 1984 - 30 Jul 1984
Contact:
FRDC

Objectives

1. Investigate biology and ecology of naturally spawned abalone
dynamics of hatchery abalone seeded into habitat vs. naturally recruited abalone
2. habitat requirements of juvenile abalone (to assess possible of bottom modification)
3. establish dietary requirements of juveniles.

Recruitment, growth, mortality and habitat use of juvenile banded morwong (Cheilodactylus spectabilis)

Project number: 1995-158
Project Status:
Completed
Budget expenditure: $21,895.00
Principal Investigator: Robert White
Organisation: University of Tasmania (UTAS)
Project start/end date: 28 Jun 1996 - 1 Jan 2002
Contact:
FRDC

Objectives

1. Determine patterns of recruitment from post-larvae to the juvenile stock on reefs.
2. Examine growth, mortality, and habitat use of juvenile fish.
3. Investigate the impact of fishing on behaviour and habitat use and overall population structure through underwater observations.

Impact of gillnet fishing on inshore temperate reef fishes, with particular reference to banded morwong

Project number: 1995-145
Project Status:
Completed
Budget expenditure: $145,513.00
Principal Investigator: Jeremy Lyle
Organisation: University of Tasmania (UTAS)
Project start/end date: 29 Dec 1995 - 30 Jul 1999
Contact:
FRDC

Objectives

1. Describe life history and population parameters of the key commercial reef fish species.
2. Determine gillnet mesh selectivity for commercial (and by-catch) reef species.
3. Determine the size/age composition of banded morwong populations at different sites off the east coast of Tasmania with particular attention to the impact of differing levels of fishing pressure.
4. Determine patterns of movement for banded morwong, wrasse and bastard trumpeter.
5. Assess the level of by-catch and discarding in the inshore gillnet fishery.
6. Conduct yield per recruit analyses to determine appropriate legal size limits.

Can spatial fishery-dependent data be used to determine abalone stock status in a spatially structured fishery?

Project number: 2017-026
Project Status:
Current
Budget expenditure: $562,128.00
Principal Investigator: Craig Mundy
Organisation: University of Tasmania (UTAS)
Project start/end date: 31 Jul 2018 - 29 Sep 2020
Contact:
FRDC

Need

With the advent of the Status of Australian Fish Stocks (SAFS) process, there is now a requirement to provide a stock ‘status’ determination in addition to the annual TACC determination. The ‘status’ reflects changes in the overall biomass, the fishing mortality, or in their proxies. This has led to disagreements among researchers, managers and industry, largely due to uncertainty around how best to derive a meaningful overall stock status indicator to meet the requirements of the SAFS reporting process. These higher-level reporting processes are an important demonstration of sustainable management of Australian fisheries, but only if stock status determinations are accurate and defensible.

Australian abalone fisheries primarily use harvest control rules based around CPUE (Kg/Hr) to set TACC. However, with abalone, stable catch-rates may not indicate stable biomass and/or stable density. Catch-rates are frequently criticised because the effort needed to take a quantity of catch may be influenced by density but also by density independent factors such as conditions at the time of fishing, experience, and the ability of fishers to adjust their fishing strategy to maintain catch rates (diver behaviour driven hyper-stability). While there are many issues with the assumption that CPUE is a reliable proxy for abundance, it is assumed to be so despite the absence of robust data to validate use of CPUE in this way. In some jurisdictions CPUE is supplemented by sparse fishery-dependent size and density data. There is an urgent need to review common assumptions, methods and interpretations of CPUE as a primary indicator, and to determine whether inclusion of spatial fishery data could provide a ‘global’ indicator of stock status for abalone fisheries.

Objectives

1. Characterise the statistical properties, coherence, interpretability and assumptions of spatial and classic indicators of fishery performance
2. Develop methods for inclusion of fine-scale spatial data in CPUE standardisations
3. Identify methods for detecting hyper-stability in CPUE
4. Determine feasibility of spatial data based stock status determination in spatially structured fisheries
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