Blue-green Algae - May 2010
Cyanobacteria (blue-green algae) are a common seasonal occurrence in Victoria and a natural component of most aquatic systems, including streams, lakes, estuaries and the sea. Many factors trigger blue-green algae blooms including nutrient loads, low inflows, low storage volumes and higher than normal temperatures.
Blue-green algae blooms are monitored regularly by water corporations and local waterway managers. When sampling and testing have confirmed the existence of blue-green algae, appropriate action is taken based on the use of the water body and the density and nature of the bloom.
The table below is a summary report of significant blooms that have occurred across the state in May. The trend is taken from the last sample report sent to Department of Sustainability and Environment during the month and the action is a summary of what has occurred. For more up to date information on a bloom, refer to the relevant Water Corporation's website.
| Drainage Basin | Location | Use | Trend | Action |
|---|---|---|---|---|
| Barwon | Painkalac Reservoir | Drinking water | ↔ | Regular Monitoring and Water Treatment. |
| Broken | Boosey Creek | Irrigation, recreation | ↑ | Warning signs erected. |
| Goulburn | Reedy Swamp | Recreation | ↔ | Warning signs erected. Media release issued. |
| Loddon | Evansford Reservoir | Drinking | ↑ | Water storage taken offline. Regular sampling. |
| Loddon | Torrumbarry Irrigation Area- Kangaroo Lake | Irrigation, Recreation, Stock & Domestic | ↔ | Warning signs erected. Regular monitoring. |
| Loddon | Torrumbarry Irrigation Area- Little Lake Charm | Irrigation, Recreation, Stock & Domestic | ↔ | Warning signs erected. Regular monitoring. |
| Loddon | Torrumbarry Irrigation Area - Racecourse Lake | Irrigation, Recreation, Stock & Domestic | ↔ | Warning signs erected. Regular monitoring. |
| Loddon | Torrumbarry Irrigation Area- Part of the No.7 Channel | Irrigation, Stock & Domestic | ↔ | Warning signs erected. Regular monitoring. |
| Mallee | Hattah Lakes | Recreation | ↓ | Warning signs erected. Regular monitoring. |
| Ovens | Diddah Diddah Reservoir | Drinking water | ↔ | Reservoir not in use. |
| South Gippsland | Leongatha Reservoir No 4 | Drinking | ↓ | Reservoir is isolated and closed. Regular monitoring. |
| Yarra | Heritage Golf and Country Club | Recreation, irrigation | ↓ | Warning signs erected at affected lakes. Regular monitoring. |
| Yarra | Royal Botanic Gardens – Ornamental Lakes | Recreation | ↔ | Warning signs erected. Users notified. |
| Yarra | Yean Yan Reservoir | Drinking | ↔ | Reservoir not in use. |
↔ = no change
↓ = blue-green algal cell counts and/or biovolumes decreasing
↑ = blue-green algal cell counts and/or biovolumes increasing