172 results
Environment
PROJECT NUMBER • 1998-212
PROJECT STATUS:
COMPLETED

Determination of the disease status of Western Australian commercial prawn stocks

There is little published information on the disease status of the prawns on the north-west shelf, yet these prawns (Fenneropenaeus merguiensis, Metapenaeus endeavouri, Penaeus esculentus and Melicertus latisulcatus) form the basis of a commercial fishery worth in excess of A$42 million in...
ORGANISATION:
Department of Primary Industries and Regional Development (DPIRD) WA
SPECIES
Environment
PROJECT NUMBER • 1998-203
PROJECT STATUS:
COMPLETED

Feeding ecology of seabirds nesting at the Abrolhos Islands, Western Australia

Over one million pairs of seabirds breed annually on the Houtman Abrolhos island group, 60 km off the mid-western coast of Australia, the largest seabird breeding station in the eastern Indian Ocean. This report describes in detail the diets and breeding patterns of six key seabird species that...
ORGANISATION:
Department of Primary Industries and Regional Development (DPIRD) WA
Industry
Environment
PROJECT NUMBER • 1998-154
PROJECT STATUS:
COMPLETED

Analysis of the microchemistry and stable isotopic composition of the otoliths of goldband snapper (Pristipomoides multidens) as an aid to the determination of stock structure

Measurement of stable isotope ratios of oxygen (18O:16O) and carbon (13C:12C) in the earstone (sagittal otolith) carbonate from assemblages of goldband snapper, Pristipomoides multidens, from waters off northern and western Australia revealed location-specific signatures and indicated that fish...
ORGANISATION:
Department of Primary Industries and Regional Development (DPIRD) WA
Environment
PROJECT NUMBER • 1998-153
PROJECT STATUS:
COMPLETED

Mother-of-pearl (Pinctada maxima) shell: stock evaluation for management and future harvesting in Western Australia

The West Australian Pearling industry is one of Australia’s most valuable aquaculture industries, currently generating around $120 - $160 million annually. The majority of pearl shell used to culture pearls come from the pearling beds in the inshore waters near Broome. The fishery for...
ORGANISATION:
Department of Primary Industries and Regional Development (DPIRD) WA
Environment
PROJECT NUMBER • 1998-152
PROJECT STATUS:
COMPLETED

Demersal finfish resource assessment survey of the north-west slope of Western Australia

The nature and extent of demersal finfish resources in deep slope waters (>200m) off the northwest coast of Western Australia are poorly understood. Existing fish trawl, trap and line fishing effort is concentrated in shallower waters (<200m), while trawling in deep slope waters...
ORGANISATION:
Department of Primary Industries and Regional Development (DPIRD) WA

Estimating the recreational catch of the blue swimmer crab in the south-west of Western Australia

Project number: 1998-119
Project Status:
Completed
Budget expenditure: $80,380.00
Principal Investigator: Neil Sumner
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 20 Jun 1998 - 22 Dec 2000
Contact:
FRDC

Need

The recreational and commercial components of the blue swimmer crab fishery need to be managed jointly to ensure that the total catch is sustainable. The proposed research will provide important catch and effort information on the recreational sector by season and location. Data is not available for the Peel-Harvey Estuary and Swan River recreational fisheries and this study is required to address this shortfall.

Objectives

1. To estimate annual landings of blue swimmer crab made by recreational fishers on the coast and in major estuaries between Cape Naturaliste and Perth, Western Australian. Specifically:- Estimate recreational catch from (a) Geographe Bay, (b) Warnbro Sound, (c) Cockburn Sound using historical boat ramp and beach recreational survey data.- Estimate recreational catch and effort from unsurveyed estuaries (Swan and Peel-Harvey). Note: the Leschenault Estuary is being done by an independent study.- Compile a table of commercial and recreational catch share for Geographe Bay, Warnbro Sound, Cockburn Sound, Peel Harvey Estuary, Swan Estuary and Leschenault Estuary.

Final report

Enhancement of yabbie production from farm dams

Project number: 1997-319
Project Status:
Completed
Budget expenditure: $419,914.00
Principal Investigator: Craig Lawrence
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 22 Jun 1997 - 31 Oct 2005
Contact:
FRDC

Need

The yabby industry in consultation with researchers from the Fisheries Department of WA have identified the following areas of research required to sustain the continued growth of this relatively new form of aquaculture

1. FEEDING AND NUTRITION
The previous FRDC project demonstrated that there was considerable scope for improvement in feeding practises by farmers. Increased feed rates and the inclusion of animal based protein sources in diets result in faster yabbie growth. Industry now requires the evaluation of alternative feeds using on-farm sources of low cost feeds. In addition to types of feed, the optimum feeding rates need to be determined.

Due to the large distances between farm dams, industry also requires the evaluation of alternative feeding practises such as automatic feeders.

A number of new diets are either being produced or currently being formulated by small business, farmers and universities. Industry requires trials to determine the effectiveness and economic viability of these new diets.

Feeding experiments for yabbies cannot be achieved in farm dams due to the variability of production between dams and lack of ability to measure stocks precisely. These experiments need to be run at the Avondale Farm Dam Aquaculture Research Station, where controlled conditions prevail, providing sound replication, with established controls, repeatability and known variation between ponds.

2. OXYGENATION
Increased feeding rates result in decreased dissolved oxygen levels on the bottom of dams where yabbies live. In addition, the centre of most dams acts as a nutrient sink resulting in anaerobic conditions avoided by yabbies. Previous experiments have demonstrated that growth is highly density dependant. Therefore, the rejuvenation of these anaerobic areas will effectively lower density (yabbies/m2) by providing more area to inhabit and thus increase growth. The connection of power to widely dispersed and isolated farm dams for mechanical aeration is not economically feasible.

In preliminary experiments at the Avondale Farm Dam Aquaculture Research Station it was shown that dissolved oxygen levels can be increased using a cheap chemical additive, while at the same time converting anaerobic sediments to aerobic sediments. The optimal application rate of this chemical for increased yabbie production needs to be quantified.

3. HUSBANDRY
Industry is investigating the potential for winter production, using shallow purpose built ponds. In order to assess whether these ponds are feasible an economic evaluation is required.

To increase farm dam production, farmers require methods of identifying the most productive regions of the south west and indices of which dams are the most productive. This continues our previous extension work investigating factors limiting production and the variation in yields between farm dams.

The previous FRDC project demonstrated that trap harvesting may be having a negative selection impact upon the yabby gene pool. Trapping selectively removes faster growing animals and males, while leaving slower growing animals and females to breed. The application of alternative harvesting methods needs to be evaluated.

4. POLYCULTURE
Predator polyculture was proposed by researchers in WA over three years ago and farmers are currently stocking either silver perch or black bream into yabby dams, to harvest both fish and yabbies. To determine the viability of this approach, industry requires an economic evaluation of polyculture. This needs research data on survival rate, growth rate, feed cost and yield of both fish and yabbies.

Objectives

1. Objectives are divided into those which are A) Continuing and build upon results of current research or B) New which are new areas of research requested by industry at the annual Yabby Producers Association Seminar.I. FEEDING AND NUTRITIONA) Continuing1. Evaluate alternative feeds using on-farm sources of low cost feed ingredients.2. Determine the optimum feeding rates B) New3. Evaluate application methods such as autofeeders. 4. Test new diets and feeding regimes currently being formulated by small business, farmers and universities.
2. II. OXYGENATIONA) Continuing1. Determine optimum application rate of chemical pond additive2. Quantify the effects of pond additive upon dissolved oxygen and yabby productionB) New3. Trial alternative aeration methods
3. III. HUSBANDRYA) Continuing1. Identify the most productive southwest regions 2. Identify indicators of productive dams .B) New3. Economic evaluation of winter production in shallow purpose built ponds.4. Evaluate harvesting and management strategies to improve yabbie gene pool.
4. IV. POLYCULTUREB) New1. Test species for polyculture as requested by industry2. Evaluate stocking rates of these species3. Prepare an economic evaluation on polyculture

Final report

ISBN: 1-877098-65-5
Author: Craig Lawrence
Industry
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