Update – 31 March 2013:
An Ella Lake resident has just reported that the Blue-green Algae bloom is still persisting. So all local residents, cottagers and fishermen should continue to refrain from drinking, boiling, or using the water for the sauna.
Dr. Andrea Kirkwood, Faculty of Science, University of Ontario Institute of Technology has taken a special interest in our winter outbreak, and has offered to examine a sample to determine the strain of blue-green algae present in Ella Lake.
Vermilion River Stewardship and the Beaver Lake Sports and Cultural Club are very concerned about public safety, and have requested signage warning of the blue-green algae to be posted at Ella Lake and Wabagishik Lake boat launches.
Contact and General Information
If you think you are experiencing symptoms related to exposure to blue-green algae (e.g., stomach cramps, diarrhea, vomiting, headache, fever, muscle weakness, difficulty breathing), contact your doctor right away.
If your pet displays symptoms such as seizures, vomiting, or diarrhea after contact with surface water, contact your veterinarian right away.
Report a blue-green algae bloom or a case with potential health effects caused by blue-green algae by calling the Sudbury and District Health Unit at 705 522-9200.
For more information about blue-green algae, check out the Sudbury and District Health Unit’s website.
What are blue-green algae?
Blue-green algae, also known as Cyanobacteria, are a group of photosynthetic bacteria that many people refer to as “pond scum.” Blue-green algae are most often blue-green in color, but can also be blue, green, reddish-purple, or brown. Blue-green algae generally grow in lakes, ponds, and slow-moving streams when the water is warm and enriched with nutrients like phosphorus or nitrogen.
When environmental conditions are just right, blue-green algae can grow very quickly in number. Most species are buoyant and will float to the surface, where they form scum layers or floating mats. When this happens, we call this a “blue-green algae bloom.” Blue-green algae blooms generally occur between mid-June and late September, although in rare instances, blooms have been observed in winter, even under the ice – such as this winter on Ella Lake.
Many different species of blue-green algae occur in Ontario waters, and it is not always the same species that blooms in a given waterbody, and the dominant species present can change over the course of the season.
How do blue-green algae differ from true algae?
Blue-green algae, like true algae, make up a portion of the phytoplankton in many water bodies. However, blue-green algae are generally not eaten by other aquatic organisms, and thus are not an important part of the food chain. True algae (e.g., green algae) are very important to the food chain. They are known as “primary producers”, a name given to living organisms that can convert sunlight and inorganic chemicals into usable energy for other living organisms. Most algae are microscopic and serve as the main supply of “high energy” food for larger organisms like zooplankton, which in turn are eaten by small fish. Small fish are then eaten by larger fish, and both small and large fish are eaten by mammals, raptors, and people.
What are the concerns associated with blue-green algae?
Concerns associated with blue-green algae include discolored water, reduced light penetration, taste and odor problems, dissolved oxygen depletions during die-off, and toxin production. Discolored water is an aesthetic issue, but when blue-green algae reach bloom densities, they can actually reduce light penetration, which can adversely affect other aquatic organisms both directly (e.g., other phytoplankton and aquatic plants) and indirectly (e.g., zooplankton and fish that depend on phytoplankton and plants). Blue-green algae blooms can be quite smelly, and though it is recommended that people never drink raw water, blue-green algae have been known to affect the taste of drinking water that comes from surface waters experiencing a bloom. When a blue-green algae bloom dies off, the blue-green algae cells sink and are broken down by microbes. This breakdown process requires oxygen and can create a biological oxygen demand. Increases in biological oxygen demand result in decreases in oxygen concentration in the water, and this can adversely affect fish and other aquatic life, and can even result in fish kills.
Blue-green algal toxins are naturally produced chemical compounds that sometimes are produced inside the cells of certain species of blue-green algae. These chemicals are not produced all of the time and there is no easy way to tell when blue-green algae are producing them and when they are not. When the cells are broken open, the toxins may be released. Sometimes this occurs when the cells die off naturally and they break open as they sink and decay in a lake or pond. Cells may also be broken open when the water is treated with chemicals meant to kill algae, and when cells are swallowed and mixed with digestive acids in the stomachs of people or animals. The only way to be sure if the toxins are present is to have water samples analyzed in a laboratory using sophisticated equipment.
Are blue-green algae blooms a new problem?
No. Fossil evidence suggests that blue-green algae have been around for millions of years. Scientists have recorded blue-green algae blooms dating back to the 12th century and they have documented the toxic effects to livestock for more than 100 years. However, it is possible that the frequency and duration of blooms are increasing in some waters as a result of increased nutrient concentrations. Nutrients, particularly phosphorus and nitrogen, can be carried into water bodies as a result of many human activities, including agriculture, discharge of untreated sewage, and use of phosphorus-based fertilizers and detergents. Inundations associated with hydroelectric power generation that hold water back from the downstream flow can also result in degraded water quality, and conditions that are ripe for blue-green algae.