Objectives: 1. Investigate bacteriological depuration of oysters. ; 2. Assess the effectiveness of sterilisation of the seawater to be used for depuration by ultraviolet and ozone units 3. establish their limits & optimise their use in terms of cost & bacterial destruction
The Origin Of Recruits To The East Coast Yellowfin Tuna Fishery And The Delineation Of The Structure Of Yellowfin Stocks In The Western Pacific
Funder
Fisheries Research and Development Corporation
Funding Amount
$549,631.19
Summary
Objectives: 1. To develop the use of microsatellites for the genetic analysis of yellowfin tuna 2. To determine the genetic relationships of yellowfin tuna form the Coral Sea To those from the east coat of Australia and to those from other Western Pacific fisheries 3. To develop techniques for estimation of oxygen 18/16 isotopic ratios in otoliths using SIMS microprobe 4. Using analysis of otolith chemistry and isotopic ratios examine the hypothesis that all recruits to th ....Objectives: 1. To develop the use of microsatellites for the genetic analysis of yellowfin tuna 2. To determine the genetic relationships of yellowfin tuna form the Coral Sea To those from the east coat of Australia and to those from other Western Pacific fisheries 3. To develop techniques for estimation of oxygen 18/16 isotopic ratios in otoliths using SIMS microprobe 4. Using analysis of otolith chemistry and isotopic ratios examine the hypothesis that all recruits to the ECTUNA fishery are derived from spawning grounds in the Coral Sea 5. In the event of rejection of the null hypothesis that there is a single panmictic WP stock, use otolith chemical data collected from yellowfin collected throughout WP to estimate the proportion of immigrant recruits and determine their most likely origin Read moreRead less
Southern Bluefin Tuna are large, fast, pelagic predators and as such probably have a very different metabolism to most other species of cultured finfish. There is a need therefore, to develop a comprehensive understanding of the metabolic rates of SBT as a basis for improving our management and husbandry of this species.
Nutrition (food conversion ratios), responses to water quality (limiting oxygen concentrations), response to predators, fish health and environmental outcomes (e.g. ....Southern Bluefin Tuna are large, fast, pelagic predators and as such probably have a very different metabolism to most other species of cultured finfish. There is a need therefore, to develop a comprehensive understanding of the metabolic rates of SBT as a basis for improving our management and husbandry of this species.
Nutrition (food conversion ratios), responses to water quality (limiting oxygen concentrations), response to predators, fish health and environmental outcomes (e.g. waste production) are all linked to metabolic rate. Improving the management of fish in culture including the development of new feeds, optimising production and product quality and assuring sound environmental outcomes are all dependant on developing this basic knowledge.
At the Southern Bluefin Tuna (SBT) Aquaculture Subprogram Steering Committee Workshop, held on the 6th November 2002 in Port Lincoln, physiology was identified, by both industry and research sectors, as a major research priority. In particular, it was recognised that a need exists to measure SBT size-specific metabolic rates under a variety of circumstances, including tow history, handling, cage acclimation effects, water temperature, changes in oxygen levels (especially hypoxia), levels of cage fouling, feeding activity and food type. Similarly, data on SBT’s metabolic responses to stressors such as microalgae, sediment, noise and predator presence were also considered important.
This project will also provide invaluable information about metabolic rates that will inform research being conducted on the species in the wild and thereby enhance our understanding of the overall biology of this species. Importantly, the data could be used to calibrate information from tagged fish currently being collected as part of CSIRO’s ongoing research into the movement and ecology of SBT using archival tags.
The project will address Industry needs by producing the following outcomes: · Measurements of oxygen consumption on commercial-sized SBT · Incorporation of those data into metabolic model for cultured SBT · An investigation of the usefulness of microsensor technology in monitoring tuna respiration in a commercial environment. Objectives: 1. To measure SBT metabolic rates in situ in a mesocosm 2. To identify and develop methodology to make reliable, realistic and repeatable measurements of metabolic rate in SBT under commercial conditions 3. To measure the metabolic rate of SBT of differing size classes. Read moreRead less
Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: Environmental Control Of Growth And Early Maturation In Salmonids
Funder
Fisheries Research and Development Corporation
Funding Amount
$333,571.00
Summary
1. To accurately predict maturation rates and optimize photoperiod regimes to prevent early maturation.
Ambient environmental conditions mean that the Tasmanian salmon industry will always suffer from high maturation rates due to its high water temperatures and increased light intensity. Additional artificial lighting in Tasmania has been shown to reduce maturation by up to 30%; increase growth rates significantly; and delay maturation by 8 weeks (Porter et al., unpublished). While thes ....1. To accurately predict maturation rates and optimize photoperiod regimes to prevent early maturation.
Ambient environmental conditions mean that the Tasmanian salmon industry will always suffer from high maturation rates due to its high water temperatures and increased light intensity. Additional artificial lighting in Tasmania has been shown to reduce maturation by up to 30%; increase growth rates significantly; and delay maturation by 8 weeks (Porter et al., unpublished). While these strategies have improved seasonal production and have been estimated to be worth $8-16 million per year (TSGA report), seasonal fluctuations in environmental conditions and fish stocks still produce variability within their effectiveness. Trials to date have highlighted the need for increased light intensities both between sites and seasons depending on the results required. Therefore further work into the use of increased light intensity and plasma melatonin production is required.
2. To better understand the timing of oocyte maturation in relation to varied environmental conditions.
a) The development of oocytes within the gonads needs to be initiated well in advance of the fish spawning. At present it is unknown precisely when this occurs and what physiological parameters are required to allow maturation to proceed. The timing of this “gating” period will be determined as this is undoubtedly the most effective time with which to apply environmental manipulations to inhibit the maturation process to continue. The “gating mechanisms” i.e. size and energetic status will be investigated to more accurately determine the timing and duration of the application of artificial lights.
b) One hormonal candidate for the transduction of information between growth and reproductive processes is insulin-like growth factor I (IGF-I). The majority of research has investigated the interactions between the GH/IGF system and maturation during the latter stages of oocyte maturation i.e. secondary oocyte growth and development. Consequently there is a paucity of information on the impact of IGF-I on the initiation of oocyte maturation and primary oocyte growth and development. Determining the role of IGF-I at this stage would assist in our understanding of the interaction between growth and reproductive processes, and thus provide additional tools to control the timing of maturation in commercial operations. Objectives: 1. To reduce early maturation and increase growth rates using artificial photoperiod 2. To better understand the physiological and environmental mechanisms controlling sexual development in Atlantic salmon 3. To accurately determine the intensity and duration of light required to alter growth and reproductive processes in teleost fish 4. To assess the effects of seasonal variation on growth and reproduction and be able to adjust photoperiod manipulations accordingly to reduce the variability of results. 5. To develop and introduce the transfer of technology from the Tasmanian salmon industry to other sectors of South Australian aquaculture. Read moreRead less
Age Validation From Tagged School And Gummy Sharks Injected With Oxytetracycline
Funder
Fisheries Research and Development Corporation
Funding Amount
$85,272.00
Summary
Length-at-age data are an important input to the fully age-structured fishery assessment models used by SharkFAG for stock advice to SharkMAC.
School sharks and gummy sharks are currently aged by counting growth-increment bands on the articular faces of vertebrae stained with alizarin red. This method is only partly validated on captive sharks and requires further work. There is a need to validate the assumption that the bands of alizarin red stain are annual and that they provide relia ....Length-at-age data are an important input to the fully age-structured fishery assessment models used by SharkFAG for stock advice to SharkMAC.
School sharks and gummy sharks are currently aged by counting growth-increment bands on the articular faces of vertebrae stained with alizarin red. This method is only partly validated on captive sharks and requires further work. There is a need to validate the assumption that the bands of alizarin red stain are annual and that they provide reliable estimates of age. Appropriate methods for undertaking this validation were developed as part of the completed 'Southern Shark Age Validation Project' (FRDC 91/037). The recently completed 'Southern Shark Tagging project' (FRDC 93/066) was ideally timed to provide sufficient samples to properly undertake this validation. Objectives: 1. Further refine age validation of sharks by laboratory processing of vertebrae from recaptured school and gummy sharks tagged and injected with oxytetracycline as part of the recently completed FRDC funded tagging and nursery projects. Read moreRead less
Investigation Of The Characteristics And Properties Of Mixed Function Oxidases (mfo) In Commercially Significant Fish From SA Waters And Assessment Of Their Induction As A Potential Early Warning And Hence Biomarker Of Organic Pollutant Linked Stress
Funder
Fisheries Research and Development Corporation
Funding Amount
$9,145.00
Summary
Objectives: 1. To adapt methods currently developed overseas and in Port Phillip Bay to South Australian commercial fish species to indicate pollutant linked stress in fish 2. To enourage the use of these methods (if acceptable) by the relevant authorities as part of a monitoring program
Do Changes In Aeration Efficiency Of "airwick" Diffusers Explain Recent High Mortalities During Transport Of Live Fish In Bulk Bins?
Funder
Fisheries Research and Development Corporation
Funding Amount
$4,990.00
Summary
Objectives: 1. Evaluate quality changes in aeration efficiency associated with aging of "airwick" diffusers used in aerated live fish transport bins returned from overseas. 2. Determine the effect of conditioning, use and multiple re-use on aeration efficiency of "airwick" diffusers.
Evaluation Of Practical Technologies For Perfluoroalkyl (PFA) Remediation In Marine Fish Hatcheries
Funder
Fisheries Research and Development Corporation
Funding Amount
$60,000.00
Summary
Per- and poly-fluoroalklys (PFASs) are now emerging as pollutants with potentially catastrophic impact on aquaculture facilities. Two key research institutes have already demonstrated the presence of PFASs in marine fish broodstock and have observed impacts on offspring that are consistent with those observed in literature studies. As testing continues there is the expectation that the number of facilities affected will increase. To compound the challenge our understanding of the impacts of ....Per- and poly-fluoroalklys (PFASs) are now emerging as pollutants with potentially catastrophic impact on aquaculture facilities. Two key research institutes have already demonstrated the presence of PFASs in marine fish broodstock and have observed impacts on offspring that are consistent with those observed in literature studies. As testing continues there is the expectation that the number of facilities affected will increase. To compound the challenge our understanding of the impacts of PFASs on aquatic species is limited. In order to further assess these impacts, PFASs must be introduced into experimental systems in a controlled fashion and therefore we must have the capacity to remove those pollutants before release. To protect our facilities and permit PFAS impacts research there is a need to rapidly assess available PFAS treatment technologies. Objectives: 1. confirm the effectiveness of ozofractionation and linseed infused polypropylene in the removal of PFAS from seawater, 2. investigate the impacts of flow rate through fractionation chambers on PFAS removal 3. test fractionation PFA removal efficiency without ozone and with ozone at addition levels compatible with aquaculture practices.* Read moreRead less
The ability to distinguish hatchery-produced scallops from wild recruits is necessary to determine the survival and optimal size and time of deployment to the seabed in the scallop reseeding project FRDC 2002/48. Furthermore, to enable rigorous evaluation of commercial marine reseeding ventures, a means of identifying the released scallops upon recapture is required. Successful labelling of juvenile scallops will also allow researchers to estimate survival and dispersal of reseeded juveniles. ....The ability to distinguish hatchery-produced scallops from wild recruits is necessary to determine the survival and optimal size and time of deployment to the seabed in the scallop reseeding project FRDC 2002/48. Furthermore, to enable rigorous evaluation of commercial marine reseeding ventures, a means of identifying the released scallops upon recapture is required. Successful labelling of juvenile scallops will also allow researchers to estimate survival and dispersal of reseeded juveniles.
An identifying mark provides far greater sensitivity and accuracy than typical statistical-based assessment. There are a number of reported methods to discern hatchery produced animals but the methods we have chosen to test are relatively inexpensive and easy to apply to animals no greater than 4mm shell length (commercial release size). An alternative marking method, molecular analysis of scallop tissue, was evaluated and qualified opinions sought, but rejected on the basis of high expense and processing time compared with testing cheaper alternatives with demonstrated utility in other species.
Objectives: 1. To develop a method to mark hatchery reared saucer scallops to distinguish them from animals derived from wild populations. Read moreRead less