Factors Affecting The Toxicity Of The Dinoflagellate, Gambierdiscus Toxicus, And The Development Of Ciguatera Outbreaks
Funder
Fisheries Research and Development Corporation
Funding Amount
$22,600.00
Summary
Objectives: 1. Define factors influencing ciguatoxin production by cultures of Gambierdiscus toxicus. 2. Examine reef disturbance effects & significance of genetic heterogeneity in G. toxicus in toxin production. 3. Establish requirements for growth & bloom formation by G. toxicus & other dinoflagellates
Objectives: 1. Study means to determine, simply, which fish are ciguatoxic. ; 2. Determine if ciguatoxin from Qld waters is identical to classical ciguatoxin; whether any geographical or temporal trends 3. precise pharmacological action of ciguatoxin to improve treatment of victims
Risk Profile For Paralytic Shellfish Toxins In Tasmanian Periwinkles
Funder
Fisheries Research and Development Corporation
Funding Amount
$180,504.00
Summary
Recurrent harmful algal blooms in Tasmanian waters (Gymnodinium in the South and Alexandrium on the East Coast) have impacted Oyster, Mussel, Abalone and Rock Lobster industries, necessitating the implementation of biotoxin monitoring programs and harvest closures during high risk periods. It is currently unknown whether Periwinkles can accumulate paralytic shellfish toxins (PST) from Tasmanian microalgal blooms and a conservative risk management approach has been taken thus far to protect both ....Recurrent harmful algal blooms in Tasmanian waters (Gymnodinium in the South and Alexandrium on the East Coast) have impacted Oyster, Mussel, Abalone and Rock Lobster industries, necessitating the implementation of biotoxin monitoring programs and harvest closures during high risk periods. It is currently unknown whether Periwinkles can accumulate paralytic shellfish toxins (PST) from Tasmanian microalgal blooms and a conservative risk management approach has been taken thus far to protect both public health and market access.
Unlike bivalve shellfish, Abalone and Rock Lobster, there is currently no clearly defined biotoxin management plan for Periwinkles in Tasmania. As grazers, Periwinkles are loosely grouped with Urchins and Abalone, the latter of which are a proven PST risk. This Abalone biotoxin sampling plan is triggered when Tasmanian Shellfish Market Access Program (ShellMAP) closes bivalve harvest areas due to PST risk. In a conservative approach, the current recommendation is PST analysis of 20 pooled Periwinkles per Abalone block on at least a monthly basis to maintain market access. This presents a considerable cost burden to the small dive fishery and interrupts harvest operations, as PST sampling of Periwinkles is required if elevated PST are detected in Abalone, which are known to hold onto PST for longer time periods in between blooms (years).
To date, the vast majority of Periwinkle samples that have been analysed for PST were collected from weak or no bloom years or regions. Evidence from French tank trials exposing the common European Periwinkle (Littorina littorea) to Alexandrium minutum cysts containing PST showed significant toxin uptake (0.2 mg PST/kg) within six days of exposure (Neves et al, 2015). It remains unknown whether commercially harvested Tasmanian Periwinkles (Lunella undulata) are at risk of PST accumulation and if the current conservative monitoring approach is commensurate to risk. In such scenarios, risk managers will commonly outsource a preliminary risk assessment (known as a risk profile). Risk profiles are an important tool for risk managers and industry. They provide a summary of all information pertinent to food safety associated with the specific hazard/food combination. The purpose of a risk profile is to assist initial risk management activities, such as identifying future actions required (if any), and the options for food safety management programs. They also inform the level of resourcing required to control the hazard/food pairing.
This project will deliver an urgently required risk profile for PST in Periwinkles to inform future actions (if any) and provide options for cost-effective food safety management programs. This profile will: 1. Determine the risk of PST accumulation in Periwinkles in Tasmania as a result of harmful microalgal blooms during high risk exposures at peak algal bloom densities in the field and in tank trials. 2. Outline potential management options and knowledge gaps, should risk management be necessary. This includes an assessment of whether the bivalve PST regulatory limit is appropriate to use in Periwinkle risk management (currently based on shellfish serving size of 100-400g) and the spatial variability associated with sampling.
References Neves, Raquel AF, et al. "Responses of the common periwinkle Littorina littorea to exposure to the toxic dinoflagellate Alexandrium minutum." Journal of Molluscan Studies 81.2 (2015): 308-311.
Objectives: 1. Determine whether Tasmanian Periwinkles can bioaccumulate PST from Alexandrium and/or Gymnodinium microalgal blooms during both field and laboratory exposures. 2. Identify the most suitable size of biotoxin management zones for Periwinkles. 3. Assess whether the use of the bivalve PST regulatory limit is appropriate for Periwinkles by conducting a literature search and consumption survey. 4. Generate a risk profile for PST in Tasmanian wild caught Periwinkles and provide guidance for risk management. Read moreRead less
Production Of Antibodies Against Toxins Involved In Ciguatera Fish Poisoning
Funder
Fisheries Research and Development Corporation
Funding Amount
$87,050.00
Summary
Objectives: 1. Develop method of detection of ciguatoxin (CTX) to extract & purify sufficient CTX to service requirements of program. 2. Develop an en enzyme imunassay for measuring anti-CTX production. 3. Develop method of schedule immunisation to allow production of monoclonal antibodies
Seafood CRC: Understanding And Reducing The Risk Of Paralytic Shellfish Toxins In Southern Rock Lobster
Funder
Fisheries Research and Development Corporation
Funding Amount
$417,984.00
Summary
As noted in the background section, Paralytic Shellfish Toxins pose a significant economic risk to the rock lobster industry, the Tasmanian algal bloom in 2012/2013 resulted in losses to the seafood industry in the vicinity of $20million AUD and scientific data is critically needed to assist in minimising losses in future years.
Knowledge on the how rock lobsters accumulate PSTs (e.g. trophic pathway) is crucial to underpin future management strategies, including validating the use ....As noted in the background section, Paralytic Shellfish Toxins pose a significant economic risk to the rock lobster industry, the Tasmanian algal bloom in 2012/2013 resulted in losses to the seafood industry in the vicinity of $20million AUD and scientific data is critically needed to assist in minimising losses in future years.
Knowledge on the how rock lobsters accumulate PSTs (e.g. trophic pathway) is crucial to underpin future management strategies, including validating the use of species which may be more readily gathered to indicate risk (e.g. the use of farmed or wild caught mussels). Additionally, there is limited information on the elimination of PSTs from Jasus edwardsii. This data would assist industry in an event where large volumes of product have been harvested and are being held in live-containment facilities, particularly in Australia where animals can be held for several weeks in tanks. Information on persistence in the wild will also underpin decisions on potential re-direction of fishing effort to non contaminated areas.
Objectives: 1. To provide management options for industry to reduce the impacts of algal blooms. These options will potentially include: in-tank elimination conditions, testing of sentinel species to obtain early warning etc 2. To reduce technical barriers to trade for Australian rock lobsters in key markets through using the risk assessment output of the project to negotiate risk based standards. 3. To enhance R&D capability on marine biotoxins and market access in Australia. Read moreRead less
Detecting Paralytic Shellfish Toxins In Oysters - Initial Assessment Of AquaBC Rapid Test Kit
Funder
Fisheries Research and Development Corporation
Funding Amount
$29,845.00
Summary
Reliable detection of marine biotoxins is a critical requirement for any effective biotoxin monitoring program, requiring any analytical technique to be properly validated. The Neogen rapid test kit for the detection of paralytic shellfish toxin (PSTs) was successfully validated in both single lab and inter-lab validations for use in oysters, offering rapid (within 20 min) on farm results. The test was used in Tasmania to reduce business risk, (i.e. frequent testing of shellfish that can rapidly ....Reliable detection of marine biotoxins is a critical requirement for any effective biotoxin monitoring program, requiring any analytical technique to be properly validated. The Neogen rapid test kit for the detection of paralytic shellfish toxin (PSTs) was successfully validated in both single lab and inter-lab validations for use in oysters, offering rapid (within 20 min) on farm results. The test was used in Tasmania to reduce business risk, (i.e. frequent testing of shellfish that can rapidly accumulate PST within a week) and employed in South Australia for regulatory purposes (low frequency of PST detection in this region).
A key factor influencing the suitability of antibody based rapid test kits is the PST profile present in the sample to be analysed. The term PST profile describes the relative concentrations of different PST analogues that might be present in each seafood sample. These profiles differ between toxic algal species, different seafood species and their tissues. Not all PST analogues are equally detected by the antibodies of different test kits (quantified as the % cross-reactivity). These cross-reactivities are critical for ensuring reliable detection across different combinations of PST analogues that might be present in shellfish.
To determine if the AquaBC rapid test kit is suitable replacement for routine monitoring, a full validation for each seafood tissue matrix would normally be conducted to determine the probability of detection curve (probability of detection across a range of PST concentrations) for multiple PST profiles, ideally followed by an inter-laboratory validation (as was conducted for the Neogen test). However, a full validation study requires repeat testing of hundreds of samples and is therefore expensive. From our previous work with the Neogen test kit, we have identified some key performance indicators that would allow for a quick initial assessment of the new AquaBC test kit, using much reduced sample numbers. These small pilot trials would include testing the most commonly encountered PST profiles (i.e. which PST toxin analogues are present) and their relative concentrations (i.e. can we reliably detect the presence of PST at the regulatory level without obtaining too many positive results at PST levels below concern?). Rather than conducting a full validation, this project will provide an initial assessment of these parameters in regard to the PST profiles commonly encountered in TAS, SA and NSW. Should this assessment be positive, a full follow up validation may be recommended. Objectives: 1. Review & identify different PST profiles that may be encountered in TAS, SA and NSW oysters. 2. Challenge the AquaBC test kit against a range of different PST concentrations and profiles to provide an initial assessment of its suitability for detecting PST in Australian oyster tissues. Read moreRead less
Studies On Toxic Dinoflagellates Responsible For Formation Of Ciguatoxin
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Determine how populations of ciguatoxin, Gambierdiscus toxicus, vary spatially & seasonally in coral reef areas 2. examine relationship between crown-of-thorns starfish and G. toxicus 3. grow organism in pure culture; establish factors influencing toxin prod
Objectives: 1. To determine the optimal composting conditions for the starfish waste 2. To determine the effect of composting on the saponin toxin present in the starfish 3. To determine levels of faecal coliforms and heavy metals folowing composting 4. To assess the nutrient value and electrical conductivity (salinity) of the resultant compost 5. To demonstrate the effect of the resultant composts on the growth of two plants (lettuces anf radishes) in a glasshouse tr ....Objectives: 1. To determine the optimal composting conditions for the starfish waste 2. To determine the effect of composting on the saponin toxin present in the starfish 3. To determine levels of faecal coliforms and heavy metals folowing composting 4. To assess the nutrient value and electrical conductivity (salinity) of the resultant compost 5. To demonstrate the effect of the resultant composts on the growth of two plants (lettuces anf radishes) in a glasshouse trials Read moreRead less
Improved Risk Management Of Paralytic Shellfish Toxins In Southern Rock Lobster
Funder
Fisheries Research and Development Corporation
Funding Amount
$885,500.00
Summary
The $84 M lobster industry has been impacted by seasonal Tasmanian closures (up to 5+ months) due to PST contamination of hepatopancreas (HP) notably in the St Helens and Maria Island regions (up to 4 mg STX.diHCl/kg), and up to Flinders Island, with an estimated lost revenue cost of 780k (Campbell et al 2013). While only trace levels of PSTs have been detected to date in lobster tail meat, HP contamination poses significant trade barriers for key markets such as China and Hong Kong. Whil .... The $84 M lobster industry has been impacted by seasonal Tasmanian closures (up to 5+ months) due to PST contamination of hepatopancreas (HP) notably in the St Helens and Maria Island regions (up to 4 mg STX.diHCl/kg), and up to Flinders Island, with an estimated lost revenue cost of 780k (Campbell et al 2013). While only trace levels of PSTs have been detected to date in lobster tail meat, HP contamination poses significant trade barriers for key markets such as China and Hong Kong. While cooking of lobsters did not release biotoxins into the cooking water, HP is a sought after foodstuff (mainly used as a dipping sauce for tail meat) and consumed by 16% of fishers on the Tasmanian east coast and 22% on the west coast, but this has since decreased due to public health warnings. Limited evidence suggests that PST contamination of lobsters may also occasionally occur in South Australia and Victoria.
The monitoring, management and mitigation approaches for biotoxin risks in crustaceans (as spelled out in the DPIPWE Rock Lobster Biotoxin Plan and Decision Protocol) remain poorly developed. The current approach uses bivalve PST monitoring as a trigger for lobster testing, with a very limited number (5) animals tested at a prohibitive cost of 5k, which if positive (>0.8 mg/kg STX eq) leads to lengthy closures of large fishing zones.
The proposed work will refine monitoring tools to reduce the costs associated with PST biotoxin risk management of Southern Rock Lobster, including the application of cheaper and faster (and hence more frequent and more reliable) PST testing and also explore whether tests can be conducted in a non-destructive manner using haemolymph as a proxy.
In addition, tank studies of PST in lobster and field studies on the variation in toxicity, and the validation of a rapid test kit will help to inform the effectiveness of the current geographical zones in the management plan.
Potential impact of PST on lobster vigour will also be investigated using a combination of tank exposure and blood biomarker studies, the latter once calibrated also applied to Tasmanian field surveys.
Objectives: 1. Assess the applicability of Neogen PST test kits for lobster viscera 2. Exploration of Neogen PST tests on lobster haemolymph as a proxy for lobster viscera PST contamination 3. Determination of the impact of PST accumulation on lobster vigour 4. Improved definition of East Coast Tasmanian lobster management zones, based on improved understanding of dietary origin of PST (from tank studies), and improved understanding of variability ( from field studies ). Read moreRead less
Application Of An In-vitro Tissue Culture Assay For The Determination Of Paralytic Shellfish Poison (Saxitoxin Family) And Comparison To The Standard Mouse Bioassay And HPLC Assay.
Funder
Fisheries Research and Development Corporation
Funding Amount
$49,823.71
Summary
Objectives: 1. To investigate the usefulness of the in-vitro tissue culture bioassay to detect and quantify paralytic shellfish poisons (saxitoxin family) in shellfish. 2. To compare the results obtained by the tissue culture bioassay with those obtained by mouse bioassay and HPLC techniques.