Stocking programs present an opportunity for impacts to the environment to occur due to the introduction of non-endemic species primarily through three pathways:
1. The stocking of a waterway without an appropriate approval from the Administering Authority;
2. The inclusion of secondary species (including tadpoles etc.) in a consignment;
3. The supply of fish infected with pathogens or parasites.
Although it is recognised that it is not the responsibility of the finfish aquaculturist to supervise or authorise the release of fish for a stocking program, it is recommended that fingerling suppliers sight a copy of the appropriate stocking permit prior to delivery of fish to ensure that the correct species were ordered and delivered.
To remove the potential for secondary species to be included in shipments, fish suppliers must implement appropriate practices to exclude such species.
Methods may include:
- Suitable filtration of incoming water to exclude adults, juveniles, eggs and larvae of secondary species
- Suitable design and operation of discharge structures to prohibit entry of upstream swimmers into ponds or tanks
- Chemical treatment of ponds prior to stocking to kill any secondary species
- Sorting of fingerlings prior to shipment
- re-treatment of shipping waters to kill secondary species
- Undertaking a random sample of the delivered batch to ensure that no unintended species are included in the consignment
- Predelivery inspection of consignments by a suitably qualified person
The aquaculturist must ensure that all fish supplied are free of disease or parasite infections. The release of diseased stock has the potential to devastate natural populations. Methods to minimise the risk of disease transfer include:
- Maintaining adequate pond/hatchery water quality
- Maintaining adequate health management protocols to minimize the potential of pathogen/parasite transfer or introduction
- Maintaining appropriate stocking densities
- Minimising stress on fish before and during transportation
Appropriate treatment of pathogens/parasites prior to releasing fish. Treatments may be chemical or through saline or freshwater baths.
Farm Dams:
It is recognised that it is not the responsibility of the fingerling supplier to supervise or authorise the release of fish for the stocking of farm dams. Although it must be recognised that fingerling suppliers may be more current with their knowledge of the allowable stocking practices. Suppliers must provide information to purchasers of fish for farm dams, to minimise the risk of inappropriate fish stocking. Education may include:
- The provision of appropriately detailed pamphlets with each delivery to each location and purchaser
The discussion with first time buyers of the responsibilities and requirements of stocking fish in farm dams and other private waters.
Information Prepared By:
Dallas J Donovan
Information Sourced From:
