108 results
Environment
Industry
PROJECT NUMBER • 2017-190
PROJECT STATUS:
COMPLETED

Assessment of gamma irradiation as a feasible method for treating prawns to inactivate White Spot Syndrome Virus

White spot syndrome virus (WSSV) was detected in diseased farmed prawns by Biosecurity Queensland’s Biological Sciences Laboratory and confirmed by the CSIRO Australian Centre for Diagnostic Preparedness (ACDP) Fish...
ORGANISATION:
Department of Primary Industries (QLD)
SPECIES
Environment
PROJECT NUMBER • 2015-216
PROJECT STATUS:
COMPLETED

Informing inter-jurisdictional snapper management in eastern Australia

Snapper has been fished since the early development of the colony around Sydney Harbour in the late 18th century, but it was the arrival of steam power in the 1860’s that enabled fishers to start regularly targeting the abundant schools of snapper occurring in the deep-water fishing grounds...
ORGANISATION:
Department of Primary Industries (QLD)
SPECIES
Environment
PROJECT NUMBER • 1984-022
PROJECT STATUS:
COMPLETED

A study of seagrass prawn nursery grounds and juvenile prawn populations in north Queensland

Seagrasses are of immense ecological importance in marine ecosystems. Primary production rates for seagrass beds are amongst the highest recorded for marine and terrestrial systems. They have a well documented role as animal habitat, nursery grounds, and as substrate stabilizers. The proximity of...
ORGANISATION:
Department of Primary Industries (QLD)
Environment
PROJECT NUMBER • 2021-119
PROJECT STATUS:
COMPLETED

Improving bycatch reduction strategies and escape vents in Queensland Mud Crab fisheries

The Queensland Crab Fishery is an iconic fishery, which encompasses the harvest of mud crabs (Scylla serrata, the Giant Mud Crab, and Scylla olivacea, the Orange Mud Crab) and Blue Swimmer Crabs (Portunus armatus and Portunus pelagicus), predominately using baited crab pots of various designs. The...
ORGANISATION:
Department of Primary Industries (QLD)
SPECIES
Industry
PROJECT NUMBER • 2017-019
PROJECT STATUS:
COMPLETED

Freshwater fish attracting structures (FAS): Evaluating a new tool to improve fishing quality and access to fisheries resources in Australian impoundments

This document has been compiled from various sources and, to the authors’ knowledge, represents the best advice currently available regarding the use of fish attracting structures to improve recreational angling in Australian impoundments. Although the principles outlined in this document may...
ORGANISATION:
Department of Primary Industries (QLD)

Population dynamics and management of spanner crabs in southern Queensland

Project number: 1995-022
Project Status:
Completed
Budget expenditure: $262,552.00
Principal Investigator: Ian Brown
Organisation: Department of Primary Industries (QLD)
Project start/end date: 18 Dec 1995 - 30 Jun 2000
Contact:
FRDC

Objectives

1. To estimate the size of the south Queensland spanner crab stock.
2. Determine the appropriateness of existing spawning closure arrangements.
3. To determine whether catch size-distribution can be used to estimate population age-structure and growth rates.
4. To evaluate the impact of post-discard mortality amongst sub-legal crabs on yields, and promote the development (by industry) of less damaging apparatus.

Final report

Authors: Ian Brown John Kirkwood Shane Gaddes Cathy Dichmont & Jenny Ovenden
Final Report • 1999-09-01 • 13.01 MB
1995-022-DLD.pdf

Summary

Spanner crabs (Ranina ranina) represent a valuable resource to southern Queensland and northern NSW. The fishery became established in the late 1970s, and as a result of an almost exponential increase in fishing effort between 1992 and 1995 an output-controlled limited entry management arrangement was introduced. During that period catches increased from about 800 to over 3,000 t, as the fishery expanded northwards to previously unexploited grounds, and a profitable live-export market was developed in south-east Asia.
The Queensland fleet comprises some 240 vessels specifically licenced to take spanner crabs in Managed Area A, which is subject to a Total Allowable Commercial Catch (TACC), currently set at 2600 t. Another 310 vessels are licenced to fish only in Managed Area B (north of the main fishing grounds) where the TACC does not apply. At present the TACC is competitive, but in the near future an Individual Transferrable Quota (ITQ) system is to be introduced.
Trends in commercial fisheries catch-effort statistics indicate that the spanner crab stock in southern Queensland is currently being harvested at a sustainable level. However several questions remain with respect to the application of the commercial logbook data, possibly the most important of which is how well commercial catch-per-unit-effoti represents stock abundance. The spatial distribution of spanner crabs is patchy, and the fishery operates such that patches are located, targeted and fished down. This can potentially lead to a situation of hyperstability, where the stock is actually declining despite catch rates remaining constant. This highlights the expected value of the fishery-independent monitoring programme currently being planned by QDPI with (in the case of the spanner crab fishery) a significant level of cost-recovery from industry.
Previous attempts to estimate growth rate of spanner crabs resulted in little consensus, due in part to inadequate sample sizes (length-based methods) and uncertainty surrounding the effects of tagging on growth (tag-recapture methods). Our initial objective was to determine whether the length-based methods would work if the samples were very large.
 
Variability in the size-structure of even very large samples of adult crabs was so great that we could place little confidence in growth estimates obtained from this type of data. Because of this, we negotiated a change in research direction with FRDC, focussing on two alternative approaches to the question of growth rates. The first was to investigate growth in pre-recruits. The second was to quantify the likely effect of tagging on moulting and growth, and to determine the extent of growth rate differences between NSW and Queensland.
Very small spanner crabs are not taken by baited tangle nets, regardless of mesh size, so a different sampling arrangement was required. A two-track channel dredge was successful in capturing intact megalopae and early juvenile stages, which provided length frequency data of considerable value to estimating pre-recruit growth. However because of its small size only very limited samples were able to be collected. To increase the sampling volume we developed a substantially larger, hydraulically­assisted dredge. This device has been field-tested on several occasions, but it has not yet been developed and used to full effect.
Laboratory experiments demonstrated that tagging had an adverse effect on weight increase and survival of spanner crabs, suggesting that growth rate estimates based on mark-recapture techniques may be biased. Of the several different types tested, anchor tags were superior in terms of ease of application and visibility. Recognising that the results may be biased, we released 4,804 tagged crabs at sites throughout the fishing grounds, to determine whether growth of spanner crabs in Queensland waters is significantly different from that in NSW, reported in a previous study. Fourteen of the 221 crabs recaptured in 1998 had moulted, with growth male growth increments being greater than those offemales (X = 11.86 and 7.40 mm respectively). Recapture rates were significantly higher for males than females, and were also significantly greater for larger individuals of each sex. This suggests that tag mortality was greater in the smaller size-classes. Recaptured crabs had moved distances ranging from O to 45 km since release, but showed no tendency to move in any particular direction.
Our length-based assessment model has not yet been successful in producing useful estimates of the relevant stock performance indicators for use by management. This was due to the lack of contrast in the CPUE data, the relatively short data time-series, the extreme spatial and temporal variability in population size-structure and sex-ratio as represented in commercial catches and research samples, and the absence of definitive growth data.
Mitochondrial DNA analysis indicated that the east-coast spanner crab fishery comprises a single unit stock, and there thus appears to be no biological justification for separate management arrangements in different geographic areas.
 
Analysis of reproductive chronology indicates that the timing of the existing spawning closure is appropriate for minimising mortality amongst egg-bearing female spanner crabs across the entire fishery, and we recommend that the closure be retained in legislation.
 
Exploratory surveys for spanner crabs conducted in two areas outside the current fishing grounds did not reveal any significant quantity of crabs, although small numbers were captured at two sites amongst the Swain Reefs. From the available information it seems unlikely that there are any major unexploited populations of spanner crabs remaining in Queensland waters.
We have demonstrated that limb damage to undersized discarded spanner crabs has a major effect on their survival under natural conditions. Poor handling practices in the fishery result in considerable mortality amongst discarded small crabs, highlighting the need for continuing fisher education and ongoing investigation of alternative catching apparatus.
 
The two major issues for further research into the spanner crab fishery are (i) deriving a robust estimate of the species' growth rate, (ii) investigating the source of the extreme variability in size­frequency and sex-ratios in population samples.
Industry
PROJECT NUMBER • 1997-409
PROJECT STATUS:
COMPLETED

Beche-de-mer knowata product development

Commercial fishing for beche-de-mer, or sea cucumbers has been carried out in Australian waters since the early 1800's. Species of commercial interest have included: the sandfish, black teatfish, prickly redfish and the lollyfish. Of these, the sandfish is the most common commercial species and is...
ORGANISATION:
Department of Primary Industries (QLD)

Developing jungle perch fingerling production to improve fishing opportunities

Project number: 2012-213
Project Status:
Completed
Budget expenditure: $482,907.00
Principal Investigator: Michael Hutchison
Organisation: Department of Primary Industries (QLD)
Project start/end date: 14 Jun 2012 - 29 Jun 2015
Contact:
FRDC

Need

Jungle perch once occurred widely in coastal Queensland rivers, from Cape York to Northern NSW. Central and southern populations have declined or become locally extinct due to dams and weirs blocking migration pathways between saltwater (where they spawn) and freshwater habitats (where they reside as juveniles and adults). Unlike barramundi, mullet and bass; jungle perch cannot persist long-term in saltwater habitats. Barriers lead to rapid local extinction. Construction of fishways on barriers in the past 10 years has created suitable conditions for the reintroduction of jungle perch. There are limited opportunities for natural recolonisation, and remnant adult populations of local strains are too few for translocation to be a practical solution. Restocking from captive bred individuals is the only option to bring back jungle perch fisheries.

Restoring wild jungle perch fisheries is a high priority for recreational fishers in Queensland. Reintroduction of self sustaining populations in rivers in south-eastern Queensland and the Mackay-Whitsunday Region will provide angling opportunities to large populations of anglers. Development of jungle perch fingerling production will also create future opportunities to further enhance Queensland's stocked impoundments and make jungle perch accessible to even more anglers.

Recent research by DEEDI has solved much of the reproductive biology of jungle perch, which can now be spawned regularly in captivity. Jungle perch larvae are much smaller (2.3 mm) than bass and barramundi larvae and establishment of first feeding has been problematic. Strategies to promote larval feeding need to be developed. The transition from larvae to fingerlings is critical for future development of jungle perch fisheries.

Objectives

1. Develop hatchery production techniques for jungle perch fingerlings
2. Successfully release jungle perch fingerlings into suitable south-eastern Queensland and Mackay-Whitsunday regional waterways
3. Communicate with anglers on the restoration of jungle perch fisheries
4. Understand environmental factors influencing post-release survival of jungle perch in rivers.
5. Develop a jungle perch production manual for fish hatcheries

Final report

ISBN: 978-0-7345-0453-1
Author: Michael Hutchison
Final Report • 2016-03-17 • 5.18 MB
2012-213-DLD.pdf

Summary

This project has for the first time demonstrated the feasibility of hatchery production of jungle perch fingerlings. The research on jungle perch production has enabled a hatchery production manual with accompanying videos to be produced. This has given private commercial hatcheries the information needed to produce jungle perch fingerlings. Several hatcheries have already indicated an interest in producing jungle perch and will be assisted to do so in 2016. Currently jungle perch are not a permitted stocking species, so cannot be sold to fish stocking groups. However, hatcheries will be able to sell fingerlings to the aquarium trade or supply grow out facilities that could produce jungle perch for human consumption. Should jungle perch become a permitted species for stocking, this will provide hatcheries with a major new product option to sell to fish stocking groups. It would also benefit anglers by providing another iconic species for impoundment stocking programs. This could have flow-on benefits to regional economies through angler tourism.

Should the pilot reintroductions of jungle perch into streams result in self-sustaining jungle perch populations, then there will be three restored jungle perch populations close to major population centres. This will create a new opportunity for anglers not normally able to target jungle perch. Since the majority of anglers who target jungle perch are catch and release fishers, angling is expected to have minimal impact on recovery of the populations.

This project led to the development of a hatchery manual for jungle perch production and to a summary brochure. In late 2014 and in 2015 researchers were able to make the first ever releases of jungle perch fingerlings back into rivers and streams within their historical range.

Keywords: Jungle perch, Kuhlia rupestris, hatchery production, restoration, fish stocking, captive breeding, larval culture, recreational fishing.

Project products

Manual • 2.19 MB
2012-213 Jungle fingerling production manual.pdf

Summary

This manual is based on the knowledge gained by researchers at the Bribie Island Research Centre (BIRC), working on developing jungle perch Kuhlia rupestris captive breeding as part of the FRDC funded project 2012/213 “Developing jungle perch fingerling production to improve fishing opportunities”. Further refinements can certainly be made to improve larval rearing and fingerling production. This manual reports on methods that have worked at BIRC to date, and perhaps more importantly, on what didn’t work. Knowledge of what has failed will help private hatchery operators avoid mistakes as they try to further refine the jungle perch production process in their own facilities.

The manual describes each of the key parts of jungle perch production, including broodstock management, spawning induction, spawning, egg and larvae management, live feed production, pond management, pond harvesting and fingerling management. The manual also includes links to video segments to demonstrate how things were done at BIRC. Videos are integral for the use of this manual. Click on the video link at the end of each production step described in this manual. It is intended that the video segments will enhance understanding of the jungle perch production process. The videos in this document are also available in the attached video folder that accompanies DVD and USB drive versions of this document and can be viewed as stand-alone files. The written document contains the majority of the technical information required, such as stocking densities, fertilising rates, feeding rates etc. The videos demonstrate the processes, which words are not always adequate to describe.

Brochure • 453.38 KB
2012-213 Jungle perch project summary brochure.pdf

Summary

This brochure outlines the achievement of the project. It is intended to provide general information on project outcomes to recreational anglers.

It summarises the results of the project.

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