Blue-green Algae - May 2009
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 |
|---|---|---|---|---|
| Botanical Gardens | Ornamental Lake, Royal Botanical Gardens | Recreation | ↔ | Warning signs erected. |
| Broken | McCall-Say Reservoir | Drinking, Stock and Domestic | ↔ | Notifications as required and ongoing monitoring |
| Corangamite | Lake Cobden | Recreation | ↔ | Warning signs erected. Media release issued. |
| Hopkins | Lake Gillear Wildlife Reserve | Recreation | ↔ | Warning signs erected. |
| Otway Coast | Simpson Historical Park Dam | Recreation | ↔ | Warning signs erected. |
| Ovens |
Diddah Diddah Reservoir |
Drinking |
↓ | Bloom is restricted to reservoir. Supply from the reservoir has temporarily ceased. |
↔ = no change
↓ = blue-green algal cell counts and/or biovolumes decreasing
↑ = blue-green algal cell counts and/or biovolumes increasing