3 results

Species identification of Australia’s most significant octopus fishery – the Western Australian Common Octopus

Project number: 2018-178
Project Status:
Completed
Budget expenditure: $94,058.00
Principal Investigator: Anthony Hart
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 7 Dec 2019 - 29 Jun 2021
Contact:
FRDC
SPECIES

Need

Octopus aff. tetricus or the Western Australian common octopus is an endemic species of the temperate waters of Western Australia. It is closely related to the cosmopolitan O. vulgaris species complex, and the ‘gloomy octopus’, O. tetricus on the east coast of Australia and New Zealand, but has been conclusively identified as a separate species through genetic and morphometric studies (Guzik et al., 2005; Amor et al., 2014). Currently, the common octopus supports the largest single-species octopus fishery in Australia, however the animal caught is an unnamed species, and carries the species affinis “Octopus aff. tetricus” instead. This is not an ideal situation for two reasons. First, it hinders a proper assessment of its significant contribution to the Australian cephalopod fisheries harvest. For example there is no dedicated SAFs report for this species, despite the catch levels harvest being three times greater than the 'Pale Octopus' (Octopus pallidus) from Tasmania, which does have its own SAFs assessment report. Secondly, there is an industry impetus to differentiate the product in the marketplace in order to create a distinct branding of the Western Australian octopus fishery into the future. Thus there is both a scientific/administrative need and a marketing need to formalise the correct species name, and its associated common name.

Objectives

1. Develop a formal species name for Octopus aff. tetricus
2. Develop an approved common name for Octopus aff. tetricus

Final report

Author: Dr Anthony M. Hart and Dr Michael D. Amor
Final Report • 1.68 MB
2018-178-DLD.pdf

Summary

This report summarises the scientific and consultation work undertaken to identify a new species name (Octopus djinda) and new common name (Western Rock Octopus) for the species that supports Australia’s largest octopus fishery, with 734 tonnes harvested in 2022. The species had been previously referred to as Octopus cf. tetricus, or Octopus aff. tetricus, otherwise known as the Gloomy Octopus. The species is endemic to Western Australia, and the work was a collaboration between the Western Australian Fisheries and Marine Research Laboratories (Dr Anthony Hart) and Dr Michael Amor of the Royal Botanic Gardens Victoria and the Western Australian Museum. Type specimens including males and females were sampled from across the species distribution in Western Australia, including from Geraldton, Mandurah, and Esperance. Using the latest technology in evolutionary genetics and multivariate morphology, the specimens were analysed, and a scientific manuscript proving they were a unique species was submitted to the journal Zootaxa. The species’ Holotype and Paratypes were then deposited in the Western Australian Museum. Parallel to this, a stakeholder consultation process investigated a range of options for species names and common names. The new species is now called Octopus djinda, and the new common name is Western Rock Octopus. The name “djinda” is a Noongar word for star, and the Noongar are traditional custodians of the land in South-Western Australia. The description provided by this project will enable proper reporting of catch statistics for Australia’s largest and fastest growing octopus fishery.

Where did the Snapper go? Determining factors influencing the recovery of Snapper stocks on the west coast of Australia

Project number: 2018-050
Project Status:
Completed
Budget expenditure: $332,535.00
Principal Investigator: Gary Jackson
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 29 Apr 2019 - 30 Jun 2021
Contact:
FRDC
SPECIES

Need

Ensuring that connectivity and stock dynamics are well understood is crucial to determining the appropriate scale for fisheries management and assessment.
There is strong industry and management interest in determining the extent to which connectivity and stock dynamics of snapper along the west coast might have changed over time reflecting changes in environmental conditions and stock abundance.
There is a need to reassess the most appropriate scale for management of the snapper resource in WA under the new Aquatic Resources and Management Act.
There is a need to evaluate whether active-acoustic methods can improve capacity to monitor the spatial distribution and abundance of snapper in key spawning aggregations and whether these methods are complementary to the existing approaches used to assess snapper stocks in the GCB and WCB and elsewhere in Australia.

Objectives

1. Improve understanding of snapper stock connectivity between the Gascoyne and West Coast Bioregions using high-resolution genomic techniques
2. Identify evidence of key sources of recruitment to snapper stocks in the Gascoyne and West Coast Bioregions using otolith microchemistry
3. Quantify snapper egg and larval dispersal between the Gascoyne and West Coast Bioregions using high-resolution ocean circulation modelling
4. Evaluate the use of active acoustic methods for monitoring the distribution and abundance of snapper in spawning aggregations
5. Investigate possible changes in key biological parameters in snapper in the Gascoyne and West Coast Bioregions in relation to changes in environmental conditions and stock abundance

Final report

ISBN: 978-1-925415-01-8
Authors: Gary Jackson David Fairclough Emily Fisher Yasha Hetzel Mirjam Van Der Mheen Ben Scoulding Bronwyn Gillanders Patrick Reis-Santos Luciano B. Beheregaray Jonathan Sandoval-Castillo and Matias Braccini
Final Report • 2023-05-02 • 9.74 MB
2018-050-DLD.pdf

Summary

This report describes a collaborative project focused on Snapper (Chrysophrys auratus) carried out between 2018 and 2021 by researchers from the Western Australian Department of Primary Industries and Regional Development (DPIRD), Flinders University, University of Adelaide, University of Western Australia, and CSIRO. The project was co-funded by the Fisheries Research and Development Corporation and had three key aims, which were motivated by questions raised by commercial fishers in the Gascoyne and West Coast bioregions of Western Australia, about C. auratus stock structure in relation to current fishery management boundaries and the methodologies used to assess these Snapper stocks.

 

Firstly, the biological connectivity of C. auratus in waters offshore of Shark Bay (in the Gascoyne Coast Bioregion) and to the south off an area between Kalbarri and Geraldton (in the West Coast Bioregion) were investigated using population genomics, otolith chemistry and larval dispersal modelling. These studies identified, for the first time, nursery grounds inside Shark Bay that are attributable to the Gascoyne oceanic Snapper stock, confirmed the larval transport pathways linking these with known spawning grounds around islands off Shark Bay and commenced the development of a recruitment index for this stock. 

 

Secondly, a novel fishery-independent survey method, combining acoustics (sonar) with underwater cameras, termed acouptics, was trialled for monitoring C. auratus stocks off Shark Bay. The study has shown that these active acoustic methods can be used to monitor Snapper aggregations and estimate numbers of fish/biomass, providing a potential addition to the future Snapper assessment toolkit.

 

Thirdly, this project explored if there had been any changes in the biological characteristics of C. auratus in oceanic waters of the Gascoyne Coast Bioregion and northern West Coast Bioregion over the past 30 years. The study demonstrated changes in maturity of Snapper in the Gascoyne, with the updated parameters used to inform the most recent (2022) assessment of this C. auratus stock.

 

The outcomes of this project will provide the basis for a review of stock assessment approaches and management arrangements for C. auratus on the West coast of Australia. Outcomes of the acouptics work provides a conceptual basis for application in C. auratus assessment research elsewhere in Australia and New Zealand.

Developing novel remote camera approaches to assess and monitor the population status of Australian sea lions

Project number: 2017-119
Project Status:
Completed
Budget expenditure: $184,631.00
Principal Investigator: Stephen M. Taylor
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 31 Dec 2017 - 30 Dec 2019
Contact:
FRDC

Need

The Australian sea lion (Neophoca cinerea) is the only endemic species of Australian pinniped and is listed as Vulnerable under the EPBC Act due to historical reduction in numbers, declining population trends, limited biological productivity and continued bycatch in various fisheries. Measures to mitigate sea lion mortality in the Commonwealth's Southern and Eastern Scalefish and Shark Fishery include extensive gillnet fishing closures that have led to significant displacement of fishing effort. Despite the measures to protect South Australian sea lion colonies, pup production has been estimated to have declined at most South Australian colonies and overall by 2.9% per year or 4.4% per breeding cycle between 2004-2008 and 2014-2015 (Goldsworthy et al., 2015).

Gillnet exclusion areas have also been proposed in the Western Australian Demersal Gillnet and Demersal Longline Fisheries, however these have not yet been implemented, in part due to uncertainties in the current status of most Western Australian sea lion colonies and risk of unintended consequences from displaced fishing effort. Despite the high level of conservation concern for this species and the severity of fishery management measures aimed at reducing their bycatch mortality, abundance has not been estimated for most WA colonies since the early-1990s (Gales 1993). Contemporary assessments of colony status are therefore required to identify the WA colonies that are most at risk from depletion (either through fisheries bycatch or other natural or anthropogenic processes) and guide effective conservation decisions.

Historically, monitoring has involved a 'boots-on-the-ground' approach to count the numbers of pups being born. However, this approach is expensive, logistically difficult, hazardous and entirely dependent on accurate estimation of the timing of colony-specific pupping seasons. It is therefore proposed to evaluate the feasibility and cost-effectiveness of remote camera methods to collect alternative sea lion abundance estimates.

Objectives

1. Evaluate the feasibility of using remote cameras as a method for monitoring the status of Australian sea lion colonies
2. Collect sea lion abundance estimates from study colonies over an 18 month period (full breeding cycle) to update understanding of their conservation status
3. Provide continuous time-series of vision and ancillary in-situ data for other ecological or behavioural research into dynamics of WA sea lion colonies

Final report

ISBN: 978-1-921845-32-1
Authors: Mat Hourston Daniela Waltrick Stuart Blight Ainslie Denham Alex Hesp Stephen Taylor
Final Report • 2022-12-01 • 4.54 MB
2017-119-DLD.pdf

Summary

This project trialled the use of remote cameras to monitor the relative abundance of Australian sea lions (ASLs, Neophoca cinerea) at three Western Australian (WA) breeding colonies. The research was undertaken by the Department of Primary Industries and Regional Development (DPIRD) to assess whether the analysis of camera footage could be used to estimate ASL relative abundance, providing an alternative to the traditional “boots on the ground” approach (hereon in “BoG”) of visiting colonies to count animals. This report outlines the strengths and limitations of this novel approach rather than providing an update on the population status of ASLs.
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