Health protocol for the translocation of prawn broodstock into NSW and production of post-larvae for stocking into NSW prawn farms for the 2021 season

Legislation

On 1 July 2017 the NSW Biosecurity Act 2015 (the Act) commenced which provides a framework for responsibility for the biosecurity risk that is shared among the community, industry and government. The Act establishes a number of ‘biosecurity duties’ that include:

  • a general biosecurity duty
  • duties relating to Prohibited Matter, and
  • a duty to notify biosecurity events.

The general biosecurity duty supports shared responsibility through its broad scope. Any person who deals with biosecurity matter or a carrier and who knows, or ought reasonably to know, the biosecurity risk posed or likely to be posed by the biosecurity matter, carrier or dealing has a biosecurity duty to ensure that, so far as is reasonably practicable, the biosecurity risk is prevented, eliminated or minimised. The general biosecurity duty can be found in Part 3 of the Act.

To ensure compliance with the general biosecurity duty, NSW DPI recommends each NSW prawn farm develop a biosecurity plan that aims to minimise biosecurity risk to the farm and surrounding area.

Find more information on the Act and the general biosecurity duty .

Translocation, hatchery and farming protocol

The translocation or movement of prawn broodstock (of the species outlined in Appendix 1 into NSW requires sampling and treatment regimes to minimise the risk of transmission of any diseases that may impact crustacea or other fish in NSW.

This protocol outlines the specific requirements for translocating prawns into a NSW hatchery for use as broodstock, under biosecure conditions, for the purposes of producing and supplying juvenile prawns (post-larvae) to NSW prawn farms for grow-out.
Broodstock must be sourced from a disease-free population where possible.

If evidence of a significant disease is found in broodstock or post-larvae, approval will not be given for release of the post-larvae from the NSW hatchery.

Documentation requirements relating to translocation of prawns into NSW under this protocol must be provided to aquaculture.administration@dpi.nsw.gov.au and aquatic.imports@dpi.nsw.gov.au as outlined under part (9) of this protocol.

1. Purpose

This protocol describes the permit conditions and requirements for translocating prawn broodstock to NSW hatcheries from Queensland, the Northern Territory and Western Australia, and then stocking of resultant post-larvae into NSW prawn farms. This includes: pre-translocation requirements; pre and post spawning testing requirements of broodstock; post-larvae testing requirements; monitoring of post larvae held in NSW larval tanks and hatchery/water management. The requirements within this protocol have been developed to reduce the risk of translocating notifiable and emerging prawn diseases (known or unknown) to NSW.

2. Scope

This protocol covers farms with an Aquaculture Permit issued under Section 144 of the NSW Fisheries Management Act 1994 authorising the farming of prawns. This protocol takes effect as a special permit condition. Please note that all other relevant legislation also applies.

Note: At any time a formal legal instrument can take effect that may override either parts of, or the entire, protocol.

3. Broodstock pre-translocation requirements to New South Wales

a. An inspection of the NSW prawn hatchery and farm must be carried out by a competent authority approved by the NSW Chief Veterinary Officer (CVO) prior to translocation of any broodstock onto the farm, or the transfer of post-larvae produced using broodstock sourced from another State. This is to ensure that the broodstock, hatchery and farm facilities engage in best industry practice, including but not limited to appropriate biosecurity, quarantine and health investigation measures, and the facility is able to comply with this protocol. The assessment will be valid for 24 months from the date of issue, conditional upon maintenance of existing facilities, procedures and infrastructures, and demonstrated compliance with relevant protocols and permit conditions.
b.Only those species listed in Appendix 1 may be translocated into NSW under this protocol from the specified location(s) of origin.

Note: Prior to translocation, NSW DPI must be notified of the intent to ship broodstock, and the intended destination of post-larvae produced under the protocol, and copies of any enterprise level biosecurity plans that apply to the cultivation of the prawns under the protocol. Notification must be received by NSW DPI no later than two full business days prior to the expected date of importation into NSW.

4. Broodstock testing requirements

Prior to release of any prawn post larvae from the hatchery, a health check of broodstock must be undertaken by submitting prawn samples and faecal matter to a National Association of Testing Authorities (NATA) accredited veterinary diagnostic laboratory, approved by the NSW CVO to test under this protocol (refer to Appendix 2 for the list of currently approved accredited laboratories). The results from all laboratory testing completed at the time this protocol is implemented, including but not limited to notifiable diseases must be provided to the NSW CVO who reserves the right to withhold approval for translocation pending consideration of those testing results. The following requirements must be met:

a. Prior to spawning, all broodstock prawns must be subjected to cold water stress by exposure to water at least 4 degrees Celsius lower in temperature than the water from which they originated (e.g. 22 degrees Celsius if originating temperature was 26 degrees Celsius) for a period of 24 hours.
b. After cold stress treatment, the terminal end of two pleopods from each broodstock animal (one pleopod each from the first two segments of the abdomen) are to be collected from each broodstock prawn into individually labelled new sample tubes. The sampling tool used to remove the pleopods must be sterile or disinfected between each individual animal. As an example, the cutting surface of scissors should be soaked in a container of 10% bleach (containing a minimum final concentration of 0.55% w/v sodium hypochlorite) for a minimum of five (5) minutes, then rinsed thoroughly in freshwater before reusing for subsequent samples (A.M. Prince, L. Andrus, PCR how to kill unwanted DNA, Biotechniques 12 (1992) 358–360).
c. Pleopod samples must then be submitted in accordance with the requirements of the receiving laboratory for PCR testing for White Spot Syndrome Virus, Yellowhead virus genotype 1 and Yellowhead virus genotype 7. (Laboratory requirement - For viral disease testing, pleopods are to be tested in pools no greater than ten individual pleopods [i.e. pleopods from no more than five individual broodstock per pool].

If broodstock are to be retained post spawning, point d. must be completed to fulfil testing requirements of Acute Hepatopancreatic Necrosis-like Disease:

d. Faecal samples are to be collected aseptically (e.g. expressing faeces directly into the sample container to avoid cross contamination OR siphoned from individually housed broodstock) from each broodstock prawn into individually labelled new sample tubes after the cold water stress treatment. Faecal samples must be submitted in accordance with the requirements of the receiving laboratory for PCR testing for Acute Hepatopancreatic Necrosis-like Disease. Faecal samples are to be tested in pools no greater than from five individuals.

Alternatively, if broodstock do not need to be retained post spawning, points e. AND f. can be completed to fulfil testing requirements of Acute Hepatopancreatic Necrosis-like Disease, instead of point d.

e. Faecal samples are to be collected from the broodstock transport vessel immediately upon arrival at the hatchery and transferred as quickly as possible to the receiving laboratory; faecal samples must be submitted in accordance with the requirements of the receiving laboratory for PCR testing for Acute Hepatopancreatic Necrosis-like Disease. Faecal samples are to be submitted fresh; or stored at 4°C no longer than 48 hours prior to submission; or submitted at ambient temperature (20-24°C for 20-26 h) in tryptic-soy broth with 1.5% NaCl or alkaline peptone water containing 2.5% NaCl supplement. (Laboratory requirement - faecal samples are to be tested in pools no greater than from five individuals following broth enrichment; samples transported in tryptic-soy broth or alkaline peptone water will not require further enrichment).
f. At the completion of spawning, the head segment of each broodstock prawn (whole cephalothoraxes inclusive of hepatopancreas from each prawn) must be removed, placed in new individual sample jars or bags and submitted in accordance with the requirements of the receiving laboratory for PCR testing for Acute Hepatopancreatic Necrosis-like Disease. (Laboratory requirement - samples are to be tested in pools no greater than from five individuals).

Note: Consideration should be given to the time required to process broodstock samples at the laboratory (confirm timeframes with the receiving laboratory), and the required laboratory submission date to ensure results are received before the planned post-larvae stocking date.

STOCKING OF PONDS MUST NOT OCCUR BEFORE PRE-SPAWNING BROODSTOCK AND PL PCR TEST RESULTS ARE RECEIVED (tests listed at 4a. – e. and 5 a. – c.))

g. The laboratory report must be received by NSW DPI no later 24 hours prior to the intended release of post-larvae from the hatchery. Release of post-larvae from the hatchery is dependent upon laboratory results (except for PCR testing for Acute Hepatopancreatic Necrosis-like Disease and histopathology, however water cannot be released into the environment until these results have been finalised)

Additional sampling requirements:

h. Broodstock (freshly sampled, kept cool, not frozen) that show any health or behaviour issues, as well as observed moribund animals, should be notified to NSW DPI on the Emergency Animal Disease Hotline 1800 675 888 and sampled in addition to the specified numbers above.
i. Any broodstock which have died in transit or on site should be sampled and labelled separately for PCR testing (these samples may be frozen if required).

Disposal requirements:

j. Any substrate used for the conditioning of broodstock is to be flushed and cleaned of organic matter (which is to be captured and disposed of in a Council approved waste facility) prior to treatment with chlorine in accordance with requirements of 7i.

Note: Laboratory results will be valid for four weeks from the date of issue. Results validity may be extended if all points in section 7) of this protocol are followed and all influent water is treated prior to entry to the hatchery with a minimum of 30mg/L active effective chlorine for 24 hours or 200mg/L active effective chlorine for 2hrs (or equivalent disinfection procedure). Evidence of influent water disinfection must provided to aquaculture.administration@dpi.nsw.gov.au and aquatic.imports@dpi.nsw.gov.au. For assistance with sampling procedures please contact your local veterinarian or Aquatic Biosecurity Policy and Programs team on (02) 4982 1232.

5. Pre-stocking testing and sampling requirements for post-larvae.

A health check of post-larvae produced from the translocated broodstock must be performed before being released from the hatchery:

a. A minimum of three hundred (300) post–larvae samples from each individual batch1 (with equal representatives of no less than thirty (30) samples from each stocked tank contributing to the overall batch) must be submitted to a NATA accredited laboratory approved by the NSW CVO for PCR testing (White Spot Syndrome Virus, Acute Hepatopancreatic Necrosis-like Disease, Yellowhead genotype 1 and Yellowhead virus genotype 7). Pooling of post-larvae must ensure that adequate target material is sampled without undue dilution from non-target material and pool size (pool size of no greater than 10 or 15 whole post-larvae, depending on the age and size of post-larvae tested, or a pool size of no greater than 20 post-larval cephalothoraxes). Similarly, post-larvae should be of sufficient age to facilitate detection of the target pathogen e.g. Preferably no younger than PL8, but allow for sufficient time for laboratory testing prior to stocking.
b.The laboratory report must be received by NSW DPI no later than 24 hours prior to the intended release of post-larvae from the hatchery.

In addition to the above, the following health check of post-larvae produced from the translocated broodstock under this protocol must be performed on post-larvae sampled immediately prior to transfer to from the hatchery:

c. A minimum of three hundred (300) post-larvae samples from each individual batch[1] (with equal representatives of no less than thirty (30) samples examined from each stocked tank contributing to the overall batch) are to be examined by histopathology for a general health screen by  a NATA accredited laboratory approved by the NSW CVO  (i.e. the laboratory report must give results for examination of a minimum of 300 effective histopathology samples). Samples must be collected prior to release from the hatchery. Post-larvae can be transferred into farm ponds, however no water can be released into the environment from the ponds until histopathology results have been finalised.

The laboratory report must be received by DPI within 24 hours of it being issued to the farm enterprise

d. Should the laboratory report indicate presence of diseases of concern, a Biosecurity Direction or other biosecurity instrument may be issued as appropriate.

Note: The PCR test results are valid for four weeks from the date of issue. The results from all laboratory testing completed at the time this protocol is implemented, including but not limited to notifiable diseases, must be provided to the NSW CVO. Notifiable diseases (which includes diseases listed under Schedule 2 of the NSW Biosecurity Act 2015 as Prohibited Matter, and under Schedule 1 of the NSW Biosecurity Regulation 2017 as Pests and diseases required to be notified) can be found on the legislation.nsw.gov.au website.


[1] An individual batch is defined as a group of prawn post-larvae produced from a single spawning event, and held in a tank system that uses the same source of water. Each sampling event for post larval testing must include progeny from every broodstock pair used during the spawning event.

6. Monitoring of post-larvae prior to stocking into NSW prawn farm

Post-larvae and prawns resulting from this protocol must be subject to thorough and regular visual inspection for any signs of disease. Any signs of unusual mortality or morbidity during this period must be recorded and this information provided immediately to DPI on the Emergency Animal Disease Hotline 1800 675 888 and wastewater discharge must immediately be ceased.

Note: for the purposes of this protocol ‘unusual mortality’ is defined as one of the following:

a. for each juvenile or adult population that are kept in a single tank, pond or raceway:
  • 10 or more dead prawns observed within any 24-hour period; or
  • 50 or more dead prawns observed within any 7-day period; or
  • b. for each population that are kept in a single broodstock tank, 10 or more per cent of that population observed to be dead in any 24-hour period, but excluding any spent broodstock, or
    c. any mortality in conjunction with any two of the following criteria:
    • larvae/post-larvae coming to the edge of the tank
    • larvae/post-larvae demonstrating unusual swimming patterns
    • reduced feeding and failure to thrive
    • unusual changes in the physical appearance of the larvae/post-larvae such as red or black colouration, erosion of the tails, fouling of the gills or any other physical abnormality

    7. Hatchery management and water treatment

    a.All waste water (including siphonings, the transportation/translocation of the broodstock, management of broodstock, spawning and production of larvae/post-larvae) must be:
    • retained in an enclosed effluent holding tank (to prevent interaction with other crustaceans and birds) on site, and
    • treated with a minimum of 30mg/L active effective chlorine for 24 hours or 200mg/L active effective chlorine for 2hrs, ensuring that the tank is mixed to homogenise the solution, and then
    • discharged to the effluent holding pond where it is retained to neutralise chlorine prior to final discharge from the farm.
    b.All solid wastes to be disposed of in a Council approved waste facility in a sealed plastic bag.
    c.All stock must be maintained in biosecure conditions at all times, with the hatchery/farm remaining compliant with the standards as approved by DPI during the pre-translocation hatchery and farm audits (see section 3 Pre-translocation Requirements), until the health clearance has been issued.
    d.Any live feeds are to be maintained in an area separate to broodstock and larvae/post larvae systems. Associated waste and waste water to be treated in accordance with 7a.
    e.Separate and designated equipment must be used for each of the broodstock, larvae/post larvae and live feed systems. If possible, separate staff should work in each system area.
    f.A quarantine “restricted entry” warning sign or similar is affixed to the external side of any entry door to the facility. Entry is restricted to essential staff only. Access points are to remain locked whenever the facility is unattended.
    g.Effective footbaths to be maintained at each entry/exit point to the facility and utilised both when entering and exiting the hatchery. Footbaths can be made using Virkon (made up to solution in accordance with manufacturer specifications) or 200mg/L iodine solution.
    h.A 200mg/L iodine spray or 70% ethanol solution is to be used to sanitise hands prior to entry and exit from the facility.
    i.All equipment in the hatchery must be decontaminated after use, which includes disinfection of all influent pipes, effluent pipes and air supply lines with 200mg/L active effective chlorine for 2hrs. Decontamination of equipment must be undertaken prior to entry or removal from the hatchery.
    j.Screening of all effluent must be undertaken in two separate steps:
    • Step 1: the outlet of the broodstock and larval rearing tanks must be screened prior to waste water entering the effluent pond with all collected materials disposed of in a Council approved waste facility in a sealed plastic bag
    • Step 2: the outlet of the effluent pond must be screened with all collected materials disposed of in a Council approved waste facility in a sealed plastic bag.

    Note: Active effective chlorine means the rate at which the active chlorine must be maintained.

    8. Record keeping

    Records must be kept for the following activities under this protocol:

    a.Broodstock samples collected for laboratory testing (including date, numbers, tank number, type of sample, etc.)
    b.Post-larvae samples collected for laboratory testing (including date, numbers, tank number, type of sample, etc.)
    c.Mortality in broodstock and larvae/post-larvae (dates, numbers, etc.)
    d.Waste and waste water treatment activities (dates, times, chlorination rates, tank and monitoring details, disposal locations, etc.)

    9. Shipment Documentation

    Operators must ensure all required approvals are obtained from Qld government prior to moving stock into Qld.

    In relation to the dispatch of each batch of post -larvae from the exporting hatchery from NSW, the shipper must:

    a.Prepare a declaration, prior to dispatch, stating:
    1. the species of prawn shipped;
    2. the number of prawn post larvae shipped
    3. that the requirements of this protocol have been met.
    b.Copies of the:
    1. laboratory results from (4 and 5) above; and
    2. the declaration at 9a. above must be emailed to NSW DPI to the addresses:

      aquatic.imports@dpi.nsw.gov.au and aquaculture.administration@dpi.nsw.gov.au

    Appendix 1

    Species

    Jurisdiction of Origin

    Restrictions

    Penaeus monodon

    Queensland (Qld)

    Not sourced south of Rockhampton, Qld.

    Northern Territory (NT)

    Not sourced from within a 100m radius of Darwin Harbour

    Western Australia

    No restriction

    Appendix 2: Laboratories approved for testing under this protocol

    1. Elizabeth Macarthur Agricultural Institute
    Woodbridge Road, Menangle NSW 2568
    Ph: 1800 675 623
    Email: laboratory.services@dpi.nsw.gov.au
    2. Biosecurity Sciences Laboratory
    Specimen Receipt (Loading Dock 12)
    Health and Food Science Precinct
    39 Kessels Road, Coopers Plains QLD  4108
    Ph: (07) 3708 8762 (submission enquiries)
    Fax: (07) 3708 8860
    Email: bslclo@daf.qld.gov.au
    3. JCU AquaPath Lab (Approved for WSSV and YHV PCR testing only)
    Building 32-007 James Cook Drive. JCU Townsville. QLD 4811
    Kelly Condon
    Ph. 47815537 (lab)
    Ph. 47816842 (office)
    Email: Kelly.condon@jcu.edu.au
    4. Genics Pty Ltd
    Gehrmann Laboratories, Level 5
    60 Research Road, University of Queensland
    St Lucia, QLD 4067
    Ph: 1300 895 515
    Email: info@genics.com