Pearl oyster quarantine
The following guidelines will help prevent disease and minimise its spread in pearl oyster farms.
Sourcing pearl oysters
- If you source adult oysters from the wild make sure they are healthy.
- If you source juvenile or adult oysters from farms make sure they are disease-free (i.e. where records indicate that there are no unaccountable deaths or declared diseases).
- Source oyster spat from a hatchery subject to a clean health test from a veterinary laboratory.
Introducing pearl oysters to a farm
- Use an 'all in, all out' policy for oysters in each group of longlines on the farm. Do not mix old and new batches, or spat or juvenile oysters with adult oysters.
- Isolate all introduced oysters from the rest of the oysters on the farm. This may be at the other end of a leased area or on a separate leased area owned by the same farm.
- Monitor for abnormal behaviour (persistent closure of shell valves or gaping) and deaths.
- If signs of sickness or death occur, take a sample of the sick or in-contact oysters and obtain a veterinary laboratory diagnosis.
- If the introduced oysters have an infectious disease, you may need to destroy the oysters and disinfect net panels and any associated equipment.
- Only release the quarantined oysters into the rest of the farm when the selected quarantine period of at least 2 months has passed with no sign of sickness or death, and when a clear veterinary laboratory report has been given on any suspect oysters sampled during the quarantine period.
Within the pearl oyster farm
- Divide the farm into several groups of longlines to prevent the spread of disease and parasites. Keep each group of longlines separate from other groups. Use separate equipment for each group or disinfect all equipment between uses on different groups. This includes staff clothing and footwear.
- Conduct regular health checks on a random sample of pearl oysters. Open a sample of oysters and check the mantle position on the valves and the condition and appearance of the organs. Also check the degree and type of fouling of the shell valves.
Managing disease outbreaks
- It is a legal requirement to contact Fisheries Queensland on 13 25 23 for any disease outbreak.
- Contain any infection associated with sickness or deaths to the affected group of longlines.
- Collect and destroy all dead oysters each day.
- Prevent birds, animals and people from spreading diseased and infected oysters on the farm.
- Seek veterinary help to determine the cause of any losses.
- Collect specimens of affected oysters for testing.
- In the case of highly infectious diseases, destroy all the oysters in the group of longlines and disinfect the panels prior to restocking.