Cyanobacteria is a microscopic bacteria that gets its name from its bluish pigment phycocyanin. It uses phycocyanin along with chlorophyll A to capture light for photosynthesis (T.N. & E.L. Taylor. 1993). Although cyanobacteria is often called blue-green algae it has no relationship to algae. All cyanobacterias are unicellular and many species form large macroscopic colonies that may appear like blue-green paint or scum and have a foul smell. Cyanobacteria can be found in fresh, brackish and marine waters on nearly all continents of the world.
Are you just learning about cyanobacteria? It is actually the oldest known fossil organism, dating back 3.5 billion years. To put that into perspective, the oldest known fossil rocks are 3.8 billion years old! (Olson JM 2006). Over time, cyanobacteria has played a crucial role in developing the earth’s atmosphere into the oxygen rich environment it is today through many events of photosynthesis. It is actually one of the few organisms able to convert atmospheric nitrogen into forms usable by plants for growth (T.N. & E.L. Taylor. 1993).
Cyanobacteria are arguably the most successful group of microorganisms on earth. They are the most genetically diverse; they occupy a broad range of habitats across all latitudes, widespread in freshwater, marine and terrestrial ecosystems, and they are found in the most extreme niches such as hot springs, salt works, and hypersaline bays. Photoautotrophic, oxygen-producing cyanobacteria created the conditions in the planet's early atmosphere that directed the evolution of aerobic metabolism and eukarotic photosynthesis. Cyanobacteria fulfill vital ecological functions in the world's oceans, being important contributors to global carbon and nitrogen budgets.
– Stewart and Falconer (Stewart I and Falconer IR 2008)
Cyanobacteria blooms can occur at anytime but tend to develop in warm, nutrient rich bodies of water with slight to moderate alkalinity (http://environment.gov.ab.ca/info/library/7673.pdf). The high nutrient load can be due to several factors, including: age of the body of water, fertilizer run-off, presence and number of waterfowl as well as diversity and biomass of fish and plants. These blooms can be harmful to your pond for a variety of reasons:
1) Formation of dense colonies of cyanobacteria can prevent light penetration from reaching submersed plants in the littoral zone and reduce the concentration of dissolved oxygen in the water body. This may result in death of plants as well as a fish kill.
2) Some strands of cyanobacteria can release cyanotoxins that are dangerous for animals and humans (Soong F S ET AL. 1992). It is important to note that not all cyanobacteria is toxic.
If you suspect your pond has an infestation of cyanobacteria it is important to contact a specialist. Specialists can perform on site analysis of the water for some toxins however more extensive tests may take several weeks for results (http://www.co.wayne.ny.us/Facts%20from%20cdc%20Blue%20Green.pdf). It is advised that you avoid drinking, swimming or partaking in recreational activities and irrigating with the infected water.
To manage cyanobacteria, your aquatic specialist can help you reduce the nutrient load of you pond as well as apply an effective chemical treatment.
By: Lucas Pearson, Aquatic Specialist
AQUA DOC Lake & Pond Management
For further information regarding cyanobacteria:
Olson JM (2006). "Photosynthesis in the Archean era".Photosyn. Res. 88 (2): 109–17. doi:10.1007/s11120-006-9040-5. PMID 16453059.
Pisciotta JM, Zou Y, Baskakov IV (2010). Yang, Ching-Hong. ed. "Light-Dependent Electrogenic Activity of Cyanobacteria". PLoS ONE 5 (5): e10821.doi:10.1371/journal.pone.0010821. PMC 2876029.PMID 20520829.
Soong F S, Maynard E, Kirke K, Luke C. Illness associated with blue-green algae. Med J Aust. 1992;156:67.
Stewart I and Falconer IR (2008) "Cyanobacteria and cyanobacterial toxins" Pages 271–296 in Oceans and human health: risks and remedies from the seas, Eds: Walsh PJ, Smith SL and Fleming LE. Academic Press, ISBN 0-12-372584-4.
T.N. & E.L. Taylor. 1993. The Biology and Evolution of Fossil Plants. Prentice Hall, New Jersey.