Decision Tree for determining if water quality is acceptable for the production of aquaculture species

    Shown below is the decision tree for determining water quality guidelines for the protection of aquaculture species;
    it includes a number of factors that might modify the guideline values.

    Specialist assistance may be required to complete
    the steps which involve chemical speciation/complexation, and likewise to conduct toxicity tests should they become
    necessary.

    Note that a user can make a decision on the risk-based framework and leave the process at any level.
    However, the further through the process one moves, the greater the confidence in the level of risk.
    See Section 9.4.2 (Volume 3) of the published guidelines for a worked example of the use of the decision tree for an
    aquaculturist planning to culture prawns.

    If ambient water quality exceeds the guideline value for any parameter
    then there could be a significant risk of an impact on aquacultural activities, and further investigations should be
    undertaken, in accordance with the decision framework. If ambient water quality remains below the guideline values,
    risk can be deemed to be low. However, this cannot be taken as a guarantee that problems will not occur in the future.

        Test against guideline trigger Values

   Low Risk

   High Risk

    Test against specific guideline trigger
    Values for species group
    See Vol 3 page 9.4-1

   Low Risk

   High Risk

    Examine factors that may ameliorate or
    modify the toxicity such as bioavailability,
    hardness, etc. (See Vol 2 8.3-36.)
    Check again using modified test values

   Low Risk

   High Risk

            Conduct Acute Toxicity
            Testing with local species

   Low Risk

  Culture not
  recommended

            Conduct Chronic Toxicity
            Testing with local species

  Culture not
  recommended