Commonly asked questions
Blue-green algae or cyanobacteria?Blue-green algae is an archaic name for cyanobacteria (cyano = blue-green). Because they are photosynthetic, cyanobacteria were originally classified as ‘plants’ or algae. However, cyanobacteria are in fact bacteria. Cyanobacteria are an ancient group of organisms that evolved approximately 3.5 billion years ago. They are an extremely diverse group that have adapted to a broad range of environments.
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What makes Lyngbya bloom?
Scientists are currently investigating the potential causes of Lyngbya blooms. Physical factors such as temperature, light and salinity are essential for the formation of many cyanobacterial blooms. In addition, nutrients and trace metals are required to maintain growth and metabolism in the cyanobacteria. Potential bloom triggers currently being investigated include biologically available iron, organic matter and phosphorus all of which are essential for the chemistry of photosynthesis and nitrogen fixation.
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Why is Lyngbya occurring in our Coastal waters?
The exact causes for its occurrence are still unknown but are under investigation. However, the bloom appears to be confined to areas with high light penetration where seagrass and macroalgae provide a substrate for attachment. Accessibility to bioavailable iron, organic matter and phosphorus may also be factors maintaining blooms.
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Is Lyngbya harmful?
Lyngbya can cause irritation upon contact with skin. Toxins are present which may cause dermatitis as well as eye and nose irritations. Inhalation of dried Lyngbya may exacerbate respiratory problems like asthma. There are no know reported cases of illness resulting from fish consumed from the affected areas (Queensland Health).
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What should I do if I come into contact with Lyngbya?
The main aim of first aid treatment is to wash areas of the body that have come into contact with Lyngbya as soon as possible after exposure has occurred in order to remove any residual material.
Where skin contact has occurred, it is recommended that the area be washed with water and soap. If Lyngbya could be trapped in clothing (eg. swimming costumes), the person should remove their clothing and wash the affected areas.
If there is evidence that the eyes may be irritated, the person should be encouraged to flush their eyes with clean water.
If irritation persists, symptomatic relief with cool compresses is advisable.
Medical attention should be sought if the eyes are affected or the extent and
severity of irritation is causing concern. If a person complains of respiratory
discomfort after swimming in affected water or breathing in dried algal matter,
they should also be advised to seek medical attention. This is particularly
important if the person has a pre-existing lung disease such as asthma.
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How can we make the bloom go away?
The best solution is to determine causes and prevent bloom formation. Mitigation
measures used in freshwater systems (e.g. copper based algicides, shading and
dredging) are not feasible in the dynamic coastal environment.
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Will the bloom affect fish and seagrass?
In bloom conditions Lyngbya smothers seagrasses causing decreases in
biomass. Seagrasses are an important habitat so the whole ecosystem may be impacted
by its loss. With the exception of some Siganids (rabbit fish), fish in general
tend to avoid bloom areas and most do not consume Lyngbya.
This information has been sourced from the SEQRWQMS Science Newsletter Issue
5 April 2000. For further information please contact Dr Eva Abal, Moreton Bay Waterways and Catchment Partnership on (07)
3403 4206.
Last updated: 28 March 2006
