Blue-green algae (cyanobacteria) occur in fresh-, brackish- and sea-waters throughout
the world; in Scotland, they can occur in quantity in lochs, ponds, canals and reservoirs.
While usually green or blue-green in colour, they may be blue, black, dark brown
Surveys in different parts of the world have found that between about 45% and 90%
of blooms of blue-green algae produce a range of toxins including neuro- and hepatotoxins
Algal blooms are inherently complex and assessment of the associated risks to public
health is not straightforward. Such assessments should therefore take account of
Guidelines and information have been compiled on the assessment and response to
blue-green algal blooms.