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Algae

Algae

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Alert information

For information on current recreational alerts see the status reports below, call the NSW algae hotline on 1800 999 457, or view the media releases in our Newsroom.

Algal blooms can cause waters to be unsafe for recreation in both freshwater and marine water environments. Algal alerts are issued by Regional Algal Coordinating Committees (RACCs) who are responsible for local management of algal blooms. Algal alerts reported on this web page are for recreational water use.

Algal alert reports

The summary report below provides the most recent algal data collated by the RACCs across NSW. Algal blooms may be present and not reported to the RACCs. Locations identified below were experiencing algal blooms at the date of the report. This report does not contain data from water storages managed  by  water  supply  authorities  where there is no public access.

NSW Health advises that any domestic use (including drinking) of surface water without appropriate treatment should be avoided at all times.

Algal blooms can cause waters to be unsafe for recreation in both freshwater and marine water environments. Algal alerts are issued by Regional Algal Coordinating Committees (RACCs) who are responsible for local management of algal blooms. Algal alerts reported on this web page are for recreational water use.

Algal alert reports

The summary report below provides the most recent algal data collated by the RACCs across NSW. Algal blooms may be present and not reported to the RACCs. Locations identified below were experiencing algal blooms at the date of the report. This report does not contain data from water storages managed  by  water  supply  authorities  where there is no public access.

NSW Health advises that any domestic use (including drinking) of surface water without appropriate treatment should be avoided at all times.

Algal alerts in NSW map

Algal

Algal status report

Status Region Location Major Use Trend
AMBER Murray Wakool River at Stoney Crossing Recreation, stock, domestic, irrigation NEW
AMBER Murray Wakool River at Kyalite Recreation, stock, domestic, irrigation NEW
AMBER Murray Wakool River at Wakool-Barham Road Recreation, stock, domestic, irrigation NEW
AMBER Murray Murray River at Picnic Point Recreation, stock, domestic, irrigation, potable NEW
AMBER Sunraysia Murray River at Buronga Recreation, stock, domestic, irrigation, potable NEW
AMBER Sunraysia Murray River at Mt Dispersion Recreation, stock, domestic, irrigation, potable NEW
AMBER Sunraysia Murray River at Fort Courage Recreation, stock, domestic, irrigation, potable NEW
RED Sunraysia Murray River at Lock 8 Recreation, stock, domestic, irrigation, potable NEW
AMBER Hunter Lake Liddell Rec Area West Recreation, stock, domestic, power generation STEADY
AMBER Hunter Lake Liddell Rec Area East Recreation, stock, domestic, power generation STEADY
AMBER Hunter Lake Liddell CW Inlet Recreation, stock, domestic, thermal generation RISING
AMBER Sunraysia Lake Menindee Site 19 Recreation, stock, domestic, irrigation NEW

Alerts are declared where algal cell numbers exceed the triggers identified in the Guidelines for Managing Risk in Recreational Waters released by the National Health and Medical Research Council. 

When  blue green algae 'blooms' are identified as being present they should be considered as potentially toxic to humans and animals, and the water should not be used for potable water supply (without prior treatment), stock watering, or for recreation. NSW Health advises that any domestic use (including  drinking) of  surface water without treatment should be avoided at all times.

Alert level definitions

Red alert levels represent 'bloom' conditions. The water may appear green and may have strong, musty or organically polluted odours. Blue-green algae may be visible as clumps or as scums. The 'blooms' should be considered to be toxic to humans and animals, and the water should not be used for potable  water  supply  (without  prior  treatment),  stock  watering, or for recreation.

A red level alert is in place when >50,000 cells of Microcystis aeruginosa are present or a biovolume of all toxin producing cyanobacteria exceeds 4 mm3/L. A red alert level is also triggered if the total of all cyanobacteria (toxic and non toxic) exceeds 10 mm3/L or scums are present for long periods. At red alert level, Local and Health Authorities should be contacted to assess risks to recreational users and appropriate measures should be taken to warn water users. Water should not be used for primary recreation.

At amber alert levels blue-green algae may be multiplying in numbers. The water may have a green tinge and musty or organic taste and odour. The water should be considered as unsuitable for potable use and alternative supplies or prior treatment of raw water for domestic purposes should be considered. The water may also be unsuitable for stock watering. The water remains suitable for recreational use, though commonsense should be applied if visible signs of blue-green algae are present.

Amber level alerts are triggered when Microcystis aeruginosa concentrations are between 5000 and 50,000 cells/mL or the biovolume of all cyanobacteria is between 0.4 and 4 mm3/L. At this alert level investigations increased sampling of algae is undertaken.

At green alert levels blue-green algae are present in the water at low densities, possibly signalling the early stages of the development of a bloom, or a period where a bloom is declining. At these densities, the blue-green algae do not pose a threat to recreational, stock or domestic use.

A green level alert occurs above 500 cells/mL of Microcystis aeruginosa or >0.04 mm3/L of total cyanobacterial biovolume but below the amber alert level. At this level routine sampling for algae should be undertaken.

For marine and estuarine blooms

The NHMRC algae guidelines for coastal waters for recreational uses are only based on a few species due to limited knowledge on toxic algae. Red level alerts are triggered when Karenia brevis levels exceed 10 cells/mL or when Lyngbya or Pfiesteria species are in high numbers.

About algae

Most algae are safe and are a natural part of aquatic ecosystems. However, some algae can produce toxins that can be damaging to humans, domestic animals and livestock that drink or come in contact with the water, as well as to organisms living in water. These algae can be found in freshwater as well  as  brackish  and  marine  waters.

Blue-green algae (also known as cyanobacteria) are the only group of algae known to be toxic in freshwaters. They are microscopic bacteria living in water, and are capable of photosynthesising which is why they are often called algae. Though microscopic, when they form colonies and accumulate together  they  can  become  visible  to  the  naked eye. Blue–green algae can produce potent liver and neurotoxins as well as skin irritants. However, not all blue–green algae are toxic, and even toxic species do not always produce toxins.

Many blue-green algal species are able to regulate their bouyancy and can sometimes be seen as green scums on water, or they just colour the water green. See the Key to Blooms webpage for more information on identifying blooms .

Toxic marine and estuarine algae can also affect recreational water use. Some of these algae produce toxins that can cause illness, particularly if contaminated shellfish is ingested, and  others can cause skin irritations. These algae often cannot be seen, but some cause red coloration to  water  a  phenomenon  known  as  red–tides.

  • Co-ordinate and support Regional Algal Co-ordinating Committees (RACCs)              
  • Contributes to the State Algal Coordinating Committee (SACC).              
  • Contributes to the Regional Algal Contingency Plans (RACPs).              
  • Manages algal communications including hotline, media enquiries, website and briefings to Minister.              
  • Monitors rivers and storages to service those aspects of the RACC’s reporting requirements, in accordance with the RACP and WaterNSW Service Provision Deed.              
  • Take a lead role in managing the risk of algal blooms in fresh waters by coordinating algal monitoring, management and public information (media and web based information) in surface waterways and storages where no other management organisation has a role.              
  • Liaise with other agencies affected by algal blooms in order that an integrated risk management approach is taken.              
  • Perform a knowledge broker role and facilitate communication between regional stakeholders and the State body responsible for algal management   
  • Identify knowledge gaps and encourage research to provide new information to enhance algal monitoring and management.              
  • Co-ordinate and manage regular algal information on behalf of stakeholders and ensure that water users and other stakeholders are informed.
90.8
Monday 21 August
-0.5
2,342,955 ML
2,581,749 ML
10,796 ML
1,543 ML
-11,726 ML
Monday 21 August