1. Prawn Farm Disease Response Policy
Drafting a plan to improve disease management together
- Progress and issues for improvement

2. Why we need a Policy
Aim: Industry and Government agreement on what is required
Improved co-operation
Allows appropriate preparations for all involved
Better, faster decision-making, consider all input
Training
Resource prioritisation, eg diagnostics, field staff

3. Penaeus Monodon Mortality Syndrome
March 2015 Cardwell. Similar to AHPND but:
different bacteria (Vibrio harveyi, not v. parahaemolyticus). Still free-living
Toxin genes do not appear to be in a plasmid
6-8 weeks post stocking (AHPND normally within 4 weeks)
NT broodstock, but this does not appear to be the source
70-100% mortality
Since then subsequent detections mostly in older prawns (eg 15 weeks) but not widespread
Normal
Pale & abnormal

4. Penaeus Monodon Mortality Syndrome
Jan 2016 Bundaberg 3 farms
days old
Another different bacteria (Vibrio sp)
Toxin genes appear to be in a plasmid
Separate origin to Cardwell

5. Penaeus Monodon Mortality Syndrome
PMMS pathology is new to BQ pathologists, which means:
emerging; or
introduced; or
was present but not reported / discovered
International notification as hepatopancreatitis.

6. Elements of disease response
Notification / contact lab – free advice from experts
On-farm biosecurity plan to minimise risk of spread
Sampling and diagnosis
Define extent
Destroy the pathogen
Emergency harvest/destruction, disposal, disinfection
Testing to demonstrate freedom

7. Decision points What is the objective? 3 Choices Eradication
Containment control and zoning
Management and mitigation
Need to decide with whatever evidence is available

8. Decision points Stock isolation, destruction and disinfection
How much evidence do we need?
Is it feasible on a large scale?
What triggers whole-farm isolation/ eradication?
Net harvest vs drain harvest
Are we better to get them out ASAP? Risk of spread via predators vs spread in water
Risk depends on situation – eg settlement pond, netting, size of prawns

9. How should we approach this disease?
Key evidence so far:
Treat as new / emerging disease – no evidence of incursion
Not AHPND- but almost. Name does not change our response
Causal effect still not established - precautionary approach
Origin is unknown
Environmental source is likely - eradication very unlikely
Probably not widespread at this stage
Significant potential to damage industry

10. How should we approach this disease?
Proposed aim: Containment, control and zoning
Positive diagnosis = immediate tracing and risk assessment
Emergency (net) harvest or destruction of all suspect ponds
Cease discharge from suspect and high risk ponds
Movement controls activated
BQ will support and ensure compliance

11. How should we approach this disease?
Rapidly define spread of pathogen
Test 30 prawns (assuming 10% prevalence) for toxin genes only from each ‘high risk’ pond
If evidence of significant spread- whole farm is treated as infected
Proof of freedom before movement of live or fresh prawns

12. To make this more effective…
Government has identified a need for training
Biosecurity officers / BQ vets/ Fisheries will cover aquaculture response
Queensland Biosecurity Capability Review
Joint industry-government taskforce? Eg disinfection protocol
Other expertise/ resources?
EADRA will help spread the financial risk and strengthen industry involvement

13. Thanks and good luck this season!
Phone:
Lab: