2022-02-08 Planning and Environment Committee Meeting Agenda

PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA   8 FEBRUARY 2022




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PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA                                       8 FEBRUARY 2022

           Table 1: Actions from Hincksia sordida Workshop January 2018
            SHORT TERM                           Conduct on-river surveys of Noosa sound, Noosa Waters,
                                                 Weyba Creek, the Frying Pan area. Survey Laguna Bay
            Step 1 Identify source populations   surf Zone, rocks and groyne.
                                                 Collect fresh samples of brown algae for identification
                                                 Confirm if Hincksia sordida.
            Step 2 Identify origin of nutrients | Undertake a stable isotope analysis on the H. sordida
            fueling blooms.                      samples collected. This is to occur pre bloom, during
                                                 bloom and post bloom.
                                                 Outsource stable isotope analysis under guidance of
                                                 Healthy Land and Water.
            MID-LONG TERM                        Summarize    existing water   quality data,  bore  data
                                                 (groundwater), pre flow / bloom, during flow / bloom, after
            Step 3 Develop a nutrient budget — | flow/ bloom.
            input versus outputs
                                                 Conduct bioassays — controlled experiments for Hincksia
                                                 sordida growth, factors to control include nitrogen,
                                                 nitrogen  and   phosphorus,   phosphorus,   light levels
                                                 temperature and flow.
                                                 Outsource bioassays under guidance of Healthy Land and
                                                 Water.

           1.1.   Algal Blooms in Marine and Estuarine Environments
           Algal blooms are defined as the rapid, excessive growth of algae, generally caused by high nutrient
           levels and favorable conditions. Blooms can result in deoxygenation of the water when large masses
           of algae die and decompose. Vvhen algal blooms increase in intensity and frequency, the results can
           cause community concern, health problems and ecological problems (e.g. leading to the death of
           other aquatic plants and animals).

           Like other living things, most algae need food (nutrients and minerals), warmth and light to grow.
           Several conditions are required to form blooms. The requirements vary from species to species but
           can include nutrient levels, water temperature, salinity levels, light, pH, and the extent to which a
           water body is flushed, flow conditions and weather. When conditions are right, the algae multiply
           rapidly until all the available nutrients are used. The bloom then collapses, decays and recycles its
           nutrients to the water or sediments. Nutrients stored in the sediment build up over decades. These
           nutrients can be released into the water under certain conditions (e.g. temperature inversions), and
           recycled to fuel another bloom — sometimes of a different species.

           In Noosa nuisance algal blooms tend to form under conditions such as low rainfall and dry warm
           weather during late winter, spring and early summer. These conditions in combination with spring
           northerly trade winds have caused algae blooms. The results of this include massive clean-up efforts
           and expense to remove the decaying algae from the beach (Figure 1).

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