18 results

Evaluation of methods of obtaining annual catch estimates for individual Victorian bay and inlet recreational fisheries

Project number: 2003-047
Project Status:
Completed
Budget expenditure: $380,064.00
Principal Investigator: Karina Ryan
Organisation: Agriculture Victoria
Project start/end date: 12 Jul 2003 - 31 Mar 2008
:

Need

There are four related needs that would be addressed by the proposed project:
1. Assessments that require annual estimates of the recreational fishery as well as the commercial fishery
2. Resource allocation decisions
3. Development, implementation and review of fishery management plans
4. Matching the spatial resolution of recreational fishing data to the spatial scale at which fisheries are managed.

1. Estimates of total catch are of fundamental importance for undertaking stock assessments. The need for such data is frequently identified in fishery and stock assessments for Victorian Bay and Inlet Fisheries. The total catch by the recreational sector of some key species, such as snapper, whiting and bream, may be similar to or even exceed that by the commercial sector, but annual estimates of angler catches are difficult to obtain. The recently completed NRIFS has provided estimates of total catch for each State and for the Nation as a whole. However, these data have been collected at a broader spatial scale than that at which fish stocks and fisheries are usually assessed and managed. The exercise is unlikely to be repeated at less than 5 year intervals because of the expense and time involved. Methods need to be developed that allow such data to be collected from Victoria’s recreational fisheries on an annual basis, in a cost-effective manner, and at an appropriate spatial scale.

2. Resource allocation issues between the commercial and recreational fishing sectors are of increasing importance for fisheries managers. Victoria is likely soon to implement a formal resource allocation process for key bay and inlet fish resources that will require on-going estimates of total catch by each fishing sector to determine whether or not catch sharing targets are being met. The ability to set appropriate targets for particular fish resources is currently hampered by a lack of information on total catches by the recreational sector.

3. Development of ESD-based fishery management plans for Victoria’s bay and inlet fisheries is about to commence, adding a further important management context to the provision of estimates of total catch by the recreational sector. Having current information on the extent and dynamics of the recreational sector will be important in the development, implementation and review of these management plans.

4. The NRIFS will provide a very useful State-wide snapshot of recreational fishing catches, but its findings will become increasingly outdated. The assessment and management of individual fisheries in Victoria is also usually undertaken at a finer spatial scale than that provided by the NRIFS. Although the National survey may be repeated in several years there is a need for ongoing annual estimates of total recreational catch of key species that provides data at the spatial scale at which assessment and most management occurs. The breadth and complexity of the NRIFS, and its novelty, have contributed to the extended time period needed for analysis and reporting of results (over 16 months). This is understandable and probably acceptable for a large scale survey that is unlikely to be repeated more than once every 5 years, but is less useful for stock assessment purposes where more frequent and even annual reviews are desirable.

The experience with the NRIFS, and similar methods used in New Zealand, indicates that the method is potentially extremely useful. However, its applicability to smaller spatial scales and as an ongoing survey technique remains to be tested. Regardless of which method (or combination of methods) is chosen as the most appropriate for Victoria, it is always important to trial a new survey design before it is implemented (Pollock et al. 1994).

How the proposed project would meet these needs is further outlined in B6 – Planned Outcomes.

Objectives

1. Review survey methods used in the past to estimate total annual catches of key species in Victorian marine and estuarine recreational fisheries.
2. From the results of past surveys statistically assess the costs and sampling requirements of different survey methods for providing unbiased estimates of total recreational catch and effort, with acceptable precision
3. Conduct a workshop to evaluate alternative survey methods for estimating total recreational fishing catch and effort.
4. Develop a cost-effective survey design that would, if possible, provide annual estimates of total recreational catch for key species in the main bay and inlet recreational fisheries
5. Trial the recommended design.
6. Review the success of the pilot survey at a second workshop and recommend a final survey design.

Final report

Investigations of the Gummy Shark Mustelus antarcticus Gunther from South-eastern Australian waters

Project number: 1971-003
Project Status:
Completed
Budget expenditure: $0.00
Organisation: Agriculture Victoria
Project start/end date: 28 Dec 1976 - 31 Dec 1976
:

Objectives

1. Yield as function of annual effort & legal min size
state of stocks vs. opt exploitation.
2. Biological information for yield analysis & mgt decisions. Economic information on shark fishery.
3. Effects on flesh quality & wastage of length, mesh size, area, time of day & year, gear & sea lice
Environment
Environment
PROJECT NUMBER • 1991-036
PROJECT STATUS:
COMPLETED

Development of methods to age commercially important dories and oreos

Four species of dories (Family: Zeidae) and five species of oreos (Family: Oreosomatidae) are caught in the South East Fishery (SEF). John dory and mirror dory are included in the SEF quota sytem with Total Allowable Catches (TACs), in 1993, of 240 t and 800 t, respectively. Oreos, originally a...
ORGANISATION:
Agriculture Victoria

Stock discrimination of blue-eye trevalla (Hyperglyphe antarctica) from Australian shelf waters and offshore seamounts and New Zealand

Project number: 2003-045
Project Status:
Completed
Budget expenditure: $269,037.00
Principal Investigator: Jeremy Hindell
Organisation: Agriculture Victoria
Project start/end date: 30 Aug 2003 - 30 Apr 2006
:

Need

Blue-eye trevalla is an important species in the South East Fishery. Blue-eye trevalla is taken in large quantities by the trawl and non-trawl sectors in south eastern coastal waters and around offshore seamounts. Despite the high value of this species in the trawl and non-trawl fisheries, however, there is limited information on the stock structure and appropriate management units. Bolch et al. (1993) concluded there was sufficient gene flow to prevent genetic differentiation between blue-eye trevalla off Tasmania, South Australia and NSW, but the sample sizes were small, there are limitations to allozyme electrophoresis (the method they used), and they did not sample fish from NZ. Ward and Last (1993) suggested that, given the known limitations of allozyme electrophoresis, further genetic studies based on mitochondrial DNA analyses and larger samples be undertaken. As a consequence, the relationship between fish caught off the south eastern Australian coast and those taken from offshore seamounts is unknown. The need to identify the stock structure of Blue-eye trevalla has also been identified as a high priority by the blue-eye working group and SEFAG.

In recent years, developmental trawl fishing has been occurring in the East Coast Deep Water (ECDW) fishery. Significant amounts of blue-eye trevalla have been caught in this fishery from grounds well to the east of 157ºE, and currently these fish are under the same quota restrictions that apply to the rest of the SEF trawl fishery. The large distances between the ECDW fishing grounds and grounds where most of the east coast blue-eye are caught has led fishers to question whether the ECDW fish can be considered part of the stock upon which the TAC was based. There is an urgent need to assess the stock structure of blue-eye trevalla caught throughout the SEF, the ECDW fisheries and New Zealand. The results from a study assessing the stock structure of this species will provide managers with information on potential management units.

A proposal to investigate the relationships between blue-eye trevalla caught in the ECDW zone and the SEF was submitted to AFMA in 2001, and although supported, it was not funded at this time for a number of reasons. In response to suggestions from AFMA, the MACs and SEFAG, it was decided that the proposal should be re-submitted in 2002. To address suggestions from industry and management groups that the stock structure of blue-eye needed to be evaluated over a much larger area, the extent of the project was expanded to include blue-eye samples from across south eastern Australia, including offshore seamounts (such as those off Tasmania, Norfolk and Lord Howe Islands) and New Zealand.

Objectives

1. To use otolith microchemistry and shape analyses to assess the stock relationships between blue-eye trevalla caught in 8 regions (east , west and south Tasmania, west Victoria/South Australia, east Victoria and East Coast Deep Water, Queensland/NSW shelf waters and the west coast of New Zealand)(YEAR 1).
2. To a) validate the results from otolith microchemistry and shape analyses, and b) better assess stock structure of blue-eye trevalla in the regions identified in objective 1, using mitochondrial DNA analyses (YEAR 2).
3. To determine a suitable approach for assessing stock structure in blue-eye trevalla in south-east Australia, and make recommendations on the most appropriate methods for future work (including sample size and spatial/temporal sampling), to better understand the stock structure of blue-eye trevalla in the SEF and ECDW fisheries.
4. To utilise the results from all analyses in the assessment and management of blue-eye trevalla via meetings of the relevant stakeholder groups including SETMAC, SENTMAC, AFMA and the blue-eye working group.

Final report

ISBN: 1-74146-575-3
Author: Jeremy Hindell
Final Report • 2006-12-13
2003-045-DLD.pdf

Summary

This work is principally about identifying the best method for examining the population structure of blue-eye trevalla (Hyperoglyphe antarctica). It is not, and was never intended to be, an exhaustive assessment of stock structure of blue-eye trevalla in Australia’s Fishing Zone. As such, findings on stock structure per se are preliminary only.
 
Blue-eye trevalla are a key economic species in Australia’s Fishing Zone. They are caught from NSW, around Tasmania, to Western Australia. Blue-eye are caught in both the trawl and non trawl fishing sectors, within which they are regarded as non-target and target species, respectively. The total allowable catch in 2004 was 743 tonnes across the non-trawl and trawl sectors, but only 651 tonnes were actually caught. Nonetheless, this catch had an estimated market value of more than $5 million AUD (based on average prices paid at the Sydney Fish Market). Less than 1% of blue-eye landings were discarded across the fisheries. The non trawl catch in 2004 was 567 tonnes, compared to 84 tonnes taken in the trawl sector. Most of the non-trawl catch is now taken by long lines off the east coast of Tasmania; since 2002 there has been a decline in the catch taken on drop lines. Since 1999 there has also been a decline in catches of blue-eye in the trawl sector.
 
Blue-eye trevalla are managed as a single stock. Research to date supports this management regime. Results from previous work on genetics (allozyme analyses) suggest that gene flow is sufficient to prevent genetic differentiation among fish collected from seamounts off NSW to those off Tasmania, and around the Tasmanian coast. Tagging studies suggest that juvenile fish (around 50 cm length) can move from NSW slope waters to those off eastern Tasmania; still smaller individuals (< 20 cm in length) can possibly drift between Australia and New Zealand. Despite this evidence, there is some uncertainty in whether fish from offshore seamounts, particularly those in the East Coast Deep Water, are the same
‘stock’ as those along Australia’s continental shelf.
 
This study used 4 different approaches (otolith shape analysis, otolith elemental microchemistry, otolith stable isotope analysis, mitochondrial DNA) to compare which method best delineated subpopulations of blue-eye sampled from 6 regions of the South East Fishery (SEF: NSW, east Victoria, east, south and west Tasmania, and South Australia), the East Coast Deep Water region, and New Zealand – 8 regions in total.
 
Samples of fish were collected opportunistically from commercial landings in each of these regions. Only fish with a fork length of approximately 50 cm or less were used. This enabled us to restrict the age of the fish we sampled, thereby ensuring that patterns among regions were a reflection of differences in stock structure rather than age. We collected at least 40 samples (individual fish) from all of the regions except NSW, from which we could only collect 30 fish (20 of which were of the ‘correct’ size). For each fish, we recorded the fork length, identified the sex (where possible), removed the otoliths for shape and microchemical analyses, and took tissue samples for genetic analyses.
Environment
PROJECT NUMBER • 2001-036
PROJECT STATUS:
COMPLETED

Assessment of the importance of different near-shore marine habitats to important fishery species in Victoria using standardised survey methods, and in temperate and sub-tropical Australia using stable isotope analysis

The first part of this project was a basic survey of fish use of intertidal habitats such as mangroves, mudflats and saltmarshes, which previously had hardly been considered in temperate Australian coastal waters. Mangroves (Avicennia marina) and mudflats were used by at least 41 species of fish....
ORGANISATION:
Agriculture Victoria
Adoption
PROJECT NUMBER • 2018-180
PROJECT STATUS:
COMPLETED

Benchmarking for health and productivity in aquaculture

Benchmarking is a form of evaluation undertaken by comparing a measure with a standard. With its widespread adoption across many industries, benchmarking was identified as an important area for development in aquatic industries through the national strategic plan for aquatic animal health (AQUAPLAN...
ORGANISATION:
Agriculture Victoria
Environment
Environment
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