Preliminary Assessment Of The Distribution And Potential Impact Of The Introduced Seastar Asterias Amurensis In Tasmanian Waters
Funder
Fisheries Research and Development Corporation
Funding Amount
$17,896.00
Summary
Objectives: 1. Using available information assess the current and potential impact of the seastar Asterias amurensis on SE Australian fisheries, aquaculture and ecosystems
A Preliminary Assessment Of The Genetic Population Structure Of Asterias Amurensis In Tasmania
Funder
Fisheries Research and Development Corporation
Funding Amount
$38,343.00
Summary
Objectives: 1. Determine whether the introduced seastar is the southern sub-species, Japanese and Russian populations of Asterias amurensis versicolor or a northern sub-species 2. Determine whether the Tasmanian populations are derived from one or several introductions 3. Determine whether the invasion of Tasmanian waters has been accompanied by a loss of genetic variation with respect to native populations
Colonisation Of New South Wales By Non-indigenous Marine Species: Baseline Studies At Twofold Bay, NSW
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Provide an inventory of the fauna of Twofold Bay that is subject to regular discharge of ballast water. 2. Ascertain if any exotic species have become established in the Bay
NCCP: Defining Best Practice For Viral Susceptibility Testing Of Non-target Species To Cyprinid Herpesvirus 3 -a Discussion Paper Based On Systematic Quantitative Literature Reviews
Funder
Fisheries Research and Development Corporation
Funding Amount
$124,626.00
Summary
The National Carp Control Plan (NCCP), an initiative of the Australian government, aims to reduce common carp numbers in Australian waters. A key aspect of this plan is to use a biological control agent to kill common carp in waters of the Murray-Darling basin. Since 2008 CSIRO researchers have been investigating the potential for Cyprinid herpesvirus 3 (CyHV-3) to control common carp numbers in this region as well as exploring potential negative outcomes arising from the introduction of this ex ....The National Carp Control Plan (NCCP), an initiative of the Australian government, aims to reduce common carp numbers in Australian waters. A key aspect of this plan is to use a biological control agent to kill common carp in waters of the Murray-Darling basin. Since 2008 CSIRO researchers have been investigating the potential for Cyprinid herpesvirus 3 (CyHV-3) to control common carp numbers in this region as well as exploring potential negative outcomes arising from the introduction of this exotic virus. One critical issue is the potential for non-target species (NTS) to be infected and negatively affected by CyHV-3. Susceptibility studies performed in vitro and in vivo were undertaken and used to predict in situ outcomes. These studies indicated that NTS tested were not susceptible to CyHV-3. However, since the publication of these results, stakeholder groups have raised several concerns. These concerns must be resolved to mitigate against the infection of NTS by CyHV-3 and to ensure continued stakeholder engagement. Six areas of concern have been raised by stakeholders. 1. Immune-competency status of fish was not considered in susceptibility studies 2. Techniques used to determine viral infection were perceived to be unreliable 3. Undiagnosed mortalities of NTS were not adequately addressed 4. Positive PCR test results observed in NTS were not adequately explained 5. Only mature or advanced juvenile fish were assessed for susceptibility to CyHV-3 6. The range of NTS investigated for susceptibility was limited and did not include a number of species that may be exposed to CyHV-3 It is proposed that a discussion paper be prepared to examine these issues. This paper would determine if previous susceptibility testing for CyHV-3 in the NCCP adequately addressed those issues detailed above. Using the information collected, recommendations for susceptibility testing of NTS to CyHV-3 in the context of the NCCP would be presented. The current understanding of what constitutes best practice for viral susceptibility testing at the time of the review would also be discussed. This would include a commentary on the predictive capacity of in vitro and in vivo studies when translated to the in situ environment.
Objectives: 1. The overarching objective of this project is to investigate potential problems, limitations and concerns related to viral susceptibility testing of NTS to CyHV-3 in the context of the NCCP and to define what constitutes best practice in viral susceptibility testing. 2. Review and discuss the implications of immune-competency status in pathogen susceptibility testing of aquatic organisms. 3. Review the range of techniques for assessing viral infection in aquatic animals and evaluate their accuracy and reliability. 4. Discuss the occurrence and implications of undiagnosed mortalities and ‘false positives’ in pathogen susceptibility studies. 5. Determine, based on existing literature, potential differences in the susceptibility of larval, juvenile and mature fish to viruses. 6. Investigate, based on existing literature, the potential for fish and other aquatic organisms beyond those previously investigated by the NCCP to become infected by CyHV-3 as a result of actions of the NCCP. Read moreRead less
Rebuilding Ecosystem Resilience: Assessment Of Management Options To Minimise Formation Of ‘barrens’ Habitat By The Long-spined Sea Urchin (Centrostephanus Rodgersii) In Tasmania
Funder
Fisheries Research and Development Corporation
Funding Amount
$828,551.00
Summary
There is clearly potential for C. rodgersii barrens to cover ~50% of nearshore reefs on the east coast of Tasmania, as is already the case in NSW and the Kent Group in Bass Strait. This would reduce both the Tasmanian abalone and rock lobster fisheries by ~15%, with a loss of value totalling ~$25M (before processing). The need for a management response is self evident.
Large rock lobsters (=135 mm CL) are the key predators of C. rodgersii in Tasmania, and experiments have shown clearly ....There is clearly potential for C. rodgersii barrens to cover ~50% of nearshore reefs on the east coast of Tasmania, as is already the case in NSW and the Kent Group in Bass Strait. This would reduce both the Tasmanian abalone and rock lobster fisheries by ~15%, with a loss of value totalling ~$25M (before processing). The need for a management response is self evident.
Large rock lobsters (=135 mm CL) are the key predators of C. rodgersii in Tasmania, and experiments have shown clearly they can prevent sea urchin populations from building to the point where overgrazing occurs. There is urgent need to assess the viability of controlling C. rodgersii populations through changing current management of the rock lobster fishery, and through targeted removal by divers as a tactical response on small scales.
However, before management instruments are invoked in an attempt to minimise the risk of further development of barrens habitat or rehabilitate existing barrens, it is imperative to carefully evaluate the effectiveness of potential management strategies. The proposed research will provide the necessary information and knowledge base to enable robust management decisions.
The proposed work has strong support from managers and the fishing industry in Tasmania, is acknowledged as a high priority by the relevant RAGs, and addresses several high priorities on both the State and TAFI strategic research plans. Objectives: 1. To assess the effectiveness of translocating large rock lobsters (=135 mm CL) en masse as means of preventing formation of incipient barrens and rehabilitating incipient and extensive barrens. 2. To assess the effectiveness of a range of management options (e.g. imposing upper size limits and spatial management) in building the biomass of large (=135 mm CL) rock lobsters to levels sufficient to limit C. rodgersii populations. 3. To assess the effectiveness of killing or removing sea urchins by abalone divers during the conduct of their fishing activity, as a means of preventing formation of incipient barrens and rehabilitating incipient and extensive barrens. Read moreRead less
Objectives: 1. Identify diseases, parasites and other organisms associated with the introduction of oysters into Australia from Japan and other possible sources. 2. Study diseases and parasites in indigenous oyster populations
Laboratory And Field Studies Of The Larval Distribution And Duration Of The Introduced Seastar Asterias Amurensis With Updated And Improved Prediction Of The Species Spread Based On A Larval Dispersal Model
Funder
Fisheries Research and Development Corporation
Funding Amount
$35,396.00
Summary
Objectives: 1. Laboratory and field studies of the larval distribution and duration of the introduced seastar Asterias amurensis with updated and improved prediction of the species spread based on a larval dispersal model
Tactical Research Fund: Aquatic Animal Health Subprogram: Viral Presence, Prevalence And Disease Management In Wild Populations Of The Australian Black Tiger Prawn (Penaeus Monodon)
Funder
Fisheries Research and Development Corporation
Funding Amount
$100,000.00
Summary
In 2012, diseased P. monodon from North-QLD farms were investigated by QDAFF, Townsville. All prawns tested negative using an OIE-endorsed YHV-1 specific PCR test but positive to GAV (YHV-2) and to YHV-1 using OIE-endorsed nested PCR tests designed to co-detect and differentiate YHV-1 from GAV. However, consistent with the YHV-1 specific PCR test data, none of the diseased P. monodon displayed histopathology consistent with acute YHV-1 infection.
Analyses undertaken at CSIRO-AAHL confi ....In 2012, diseased P. monodon from North-QLD farms were investigated by QDAFF, Townsville. All prawns tested negative using an OIE-endorsed YHV-1 specific PCR test but positive to GAV (YHV-2) and to YHV-1 using OIE-endorsed nested PCR tests designed to co-detect and differentiate YHV-1 from GAV. However, consistent with the YHV-1 specific PCR test data, none of the diseased P. monodon displayed histopathology consistent with acute YHV-1 infection.
Analyses undertaken at CSIRO-AAHL confirmed the presence of GAV but not YHV-1. In two OIE-endorsed PCR tests, GAV sequences were also amplified by primers supposed to be specific for YHV-1. When an OIE-endorsed PCR test designed to detect all YHV genotypes was applied to tissue from healthy P. monodon broodstock imported into QLD from NT, sequence analyses identified an undescribed unique genotype designated tentatively as YHV-7. YHV-7 was also amplified by a CSIRO in-house real-time PCR test designed to be specific to the YHV-1.
Wild QLD broodstock are increasingly being replaced by wild NT broodstock to produce resilient fast growing P. monodon for aquaculture. The finding of YHV-7, with unknown pathogenic potential and distribution, highlights the potential risks of translocated broodstock spreading unwanted new pathogens to regions with substantial aquaculture interest, and supports a need to update decade-old data on what viruses might exist in NT and QLD populations of P. monodon.
Collectively these discoveries highlight urgent needs to (i) re-evaluate genotype specificities of OIE-endorsed PCR tests for different YHV genotypes (ii) redesign PCR tests to improve their power to discriminate YHV-1 from less virulent genotypes and (iii) re-assess the prevalence of GAV and related genotypes (YHV-7) and other endemic viruses potentially problematic to aquaculture (MoV, MBV, HPV, SMV, IHHNV) in wild P. monodon broodstock sourced from the NT and QLD.
Objectives: 1. Determine what GAV/YHV genotypes exist and their relative prevalence in wild P. monodon populations in NT/WA/QLD from which broodstock are captured for aquaculture purposes 2. Revise PCR test designs as necessary to ensure their specificity, particularly in discriminating the highly virulent YHV-1 strain that emerged in Thailand in the early 1990’s from GAV and the other known YHV genotypic variants that appear to be far less pathogenic, and make these tests available for publication in the OIE Diagnostic Manual for Yellow head disease 3. Acquire and/or generate appropriate control nucleic acids specific to the various YHV genotypes for use in YHV-1 or other genotype-specific PCR tests so that their diagnostic specificity can be validated at key diagnostic laboratories (eg. CSIRO-AAHL), and so they can be made available to state and international laboratories with needs for equivalent diagnostic capabilities. 4. Determine the existence and prevalence of other endemic viruses [eg. Mourilyan virus (MoV), Monodon baculovirus (MBV), Hepatopancreatic parvovirus (HPV), Spawner-isolated mortality virus (SMV) and Infectious hypodermal and haematopoetic necrosis virus (IHHNV)] in wild P. monodon populations in the NT and QLD. In addition, test samples for the exotic viruses WSSV and IMNV given some broodstock are sourced from waters with a higher than usual likelihood of incursion from these pathogens. Read moreRead less