Also known as phylum cyanophyta or Myxophyceae, blue-green algae is a highly
adaptable aquatic plant that can be widely found in nature, especially in lakes,
rivers and reservoirs.
It is a particularly mysterious creature: as not all species of blue-green
algae pose a potential health threat.
While environmental conditions that encourage the growth of toxic algae are
still uncertain, it is generally acknowledged that blue-green algae multiply
very quickly in eutrophic water - that is, water with high nutrient levels.
Furthermore, as with all plants, they grow rapidly when the water is warm and
sunshine is abundant.
Under the right climate conditions, nutrient-rich Taihu Lake has provided an
ideal breeding ground for the toxic algal bloom.
High temperatures with no rain would naturally guarantee a lake with
excessive nutrients and low water levels, which experts say is another key
factor in algal outbreaks.
Taihu is China's third largest lake and contains large amounts of fertilizers
from persistent pollution.
"Bloom" describes the condition when, as in Taihu's case, algae expands
exponentially to a point where water is discolored, and its quality and oxygen
level significantly reduces. Offensive odors are produced, and fish are also
known to die.
Algal blooms also create adverse conditions to aquatic ecosystems.
Scientists today are still puzzled about how long blooms last, and when or
where they will occur.
Although algal blooms frequently occur throughout the world, instances where
human beings are poisoned from toxic blue-green algae have been rarely
No known poisonings have occurred because of the Taihu Lake water crisis.