2016-02-02 P&O Committee - Item 3 - Attachment 4 - Mary River Environmental Values and Water Quality Objectives

            Mary River environmental values and water quality objectives




            Table 4 Primary contact recreation EV: Water quality objectives for management of cyanobacteria in
            contact recreation areas

            When cyanobacteria are present in large numbers they can present a significant hazard, particularly to
            primary contact users of waters.

              Green level surveillance mode                    Amber level alert mode                       Red level action mode


                                       -1                                                  -1
            ≥ 500 to <500 cells mL                       ≥ 5000 to <50 000 cells mL                Level 1 guideline:
                                                                                                            -1
            Microsystis aeruginosa                       Microsystis aeruginosa                    ≥ 10 µg L total microsystins
                                                                             3   -1                                        -1
            or                                           Or ≥ 0.4 to <4 mm L for the               Or ≥ 50 000 cells mL toxic
                                                         combined total of all                     Microsystis aeruginosa
            biovolume equivalent of >0.04 to             cyanobacteria where a known
                     3 -1
            <0.4mm L for the combined total              toxin producer is dominant in the         Or biovolume equivalent of ≥ 4
                                                                                                        3 -1
            of all cyanobacteria.                        total biovolume                           mm L for the combined total of
                                                                                                   all cyanobacteria where a known
                                                                                                                             1
                                                         Or                                        toxin producer is dominant in the
                                                                                                   total biovolume
                                                                                 3    -1
                                                         ≥ 0.5 to <10 mm mm L for the
                                                                                                        2
                                                         combined total of all                     Or
                                                         cyanobacteria where known toxin
                                                         producers are not present.                Level 2 guideline:
                                                                                                            3 -1
                                                                                                   ≥ 10 mm L for total biovolume of
                                                                                                   all cyanobacterial material where
                                                                                                   known toxins are not present

                                                                                                   Or

                                                                                                   Cyanobacteria scums are
                                                                                                                       3
                                                                                                   consistently present .
            Source: NHMRC Guideline for Managing Risks in Recreational Water – Cyanobacteria and algae in freshwater
            (NHMRC, 2008).

            Notes:

            1.      The definition of “dominant” is where the known toxin producer comprises 75% or more of the total biovolume of
                    cyanobacteria in a representative sample
            2.      This applies where high cell densities or scums of “non toxic” cyanobacteria are present i.e. where the
                    cyanobacterial population has been tested and shown not to contain known toxins (mycrocystins, nodularian,
                    cylindrospermopsin or saxitoxin).
            3.      This refers to the situation where scums occur at the recreation site each day when conditions are calm,
                    particularly in the morning. Note that it is not likely that scums are always present and visible when there is a high
                    population as the cells may mix down with wind and turbulence and then reform later when conditions become
                    stable.




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Document Set ID: 20002123
Version: 1, Version Date: 21/12/2015