Cyanobacteria

There are many kinds of Cyanobacteria. They occur in fresh water (lakes, rivers, streams) and salt water (oceans, estuaries) as part of the natural biological community for a healthy environment. Cyanobacteria have a very important ecological role since they are among the photosynthetic group of organism that fix carbon dioxide (an important green house gas) from the atmosphere and turn it into organic carbon that filters through the food chain and eventually leads to humans and whales and back again to the atmosphere. Australia has many different kinds of Cyanobacteria in its rivers, streams, lakes, and surrounding oceans.

In just the right conditions (light, nutrient concentration etc) some cyanobacteria can form a 'bloom' where they occur in very large numbers. Sometime these blooms cause problems and are referred to as Harmful Algal Blooms. Sometime the shear numbers of these tiny creatures are enough to deprive fish swimming below of oxygen, causing fish kills. A few of these cyanobacteria produce poisons (toxins) that are harmful. Sometimes the toxins produced by these tiny creatures in the blooms reaches levels high enough to kill other organism.

Clams, mussels or oysters are filter feeding organisms. The get their nutrients by drawing in water and then filtering out the bits of organic material (cyanobacteria, other microalgae, small zooplankton etc), releasing the water back into the ocean or estuary. If the water contains toxins from the cyanobacteria, the shell fish take these toxins in. If we then eat them, we can get very sick. These sorts of Harmful Algal Blooms occur from time to time in Australia and they are very detrimental to the aquaculture industry.

There are lots of scientists involved in studying the cyanobacteria involved in harmful algal blooms. They are trying to understand why these blooms occur and they investigate ways to prevent them from happening. Here is a website from a research group at the University of Tasmania: http://www.utas.edu.au/docs/plant_science/hab/

Info from another Tasmanian web site: http://www.dpiw.tas.gov.au/inter.nsf/WebPages/RPIO-4YK9Z8?open

Other related sites:

http://www.watercare.net/wll/himp-algalblooms.html

http://www.trinity.wa.edu.au/plduffyrc/subjects/science/biology/algal.htm

http://www.nrw.qld.gov.au/water/blue_green/index.html

I hope that helps with your project.

Kind regards,

Carol