i) Causes of algal blooms

Algal blooms are caused by a combination of factors including:
• high concentrations of nutrients such as phosphorus and nitrogen
• warm stable air and water temperatures – although blooms can form in cool weather too
• low wind speeds and little turbulence
The factor over which landholders have most control is the level of nutrients washing off paddocks and out of their homes into their dams and local waterways. More information about the use of fertilisers on pastures and grazing strategies to maintain groundcover and minimise fertiliser runoff  is available in ‘Managing Pastures’ on page XX.