AGRICULTURE KNOWLEDGE CENTRE BULLETIN: BLUE-GREEN ALGAE ALERT

Released on August 20, 2007

Animal deaths attributed to blue-green algae poisoning have been reported recently in west central Saskatchewan. This is a signal to livestock producers to check all surface water bodies (dugouts, dams, lakes, sloughs, etc.) available to their animals for blue-green algae growth. Warm daytime temperatures in the summer months, combined with a nutrient rich body of fresh water, accelerate algal growth, including that of blue-green algae.

Blue-green algae is not an algae, but a bacteria called "cyanobacteria." This bacteria produces a toxin that can cause skin and eye irritation, liver damage, nervous system damage, gastroenteritis, sickness and, at times, death. The toxins are released as the cyanobacteria die off, either naturally or following treatment.

Blue-green algae will have a shimmering blue-green colour. It may also have a foamy, sheen-like appearance which looks like spilled paint floating on top of the water. Heavy blooms appear like a solid shimmering blue-green sheen across the water's surface, or have an appearance and consistency similar to pea soup.

If blue-green algae is identified in a water source, all livestock, pets and human contact should be prevented. The water will require treatment.

The most common treatment of blue-green algae in an open dugout or pond is with a registered product containing copper sulphate. A list of registered, commercially available products is contained in the Prairie Farm Rehabilitation Administration (PFRA) Fact Sheet "Copper Treatments for Dugouts" (http://www.agr.gc.ca/pfra/water/copper_e.htm). One kilogram (2.2 pounds) of copper sulphate (by weight) will treat 947,000 litres (250,000 gallons) of water.

There are two common application methods: the copper sulphate can be dissolved in warm water, which is then sprayed over the water's surface; or, the copper sulphate can be weighted into a cloth bag tied with a rope. The rope is then stretched from side to side across the water and, with the assistance of another individual; the bag can then be dragged back and forth across the water's surface dissolving the product.

The copper sulphate kills the blue-green algae, releasing toxins into the water. Therefore, it is recommended that 14 days should pass prior to any livestock, pet and/or human coming in contact with the contaminated water. If treating a dugout containing fish, it is recommended that only one-third of the dugout should be treated, using one-third of the recommended copper sulphate weight applied in treatments over a three day period.

For additional information, visit www.agr.gov.sk.ca and click on FAQs | FAQ Blue-Green Algae, or call the Agriculture Knowledge Centre at 1-866-457-2377.

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For more information, contact:

Jenna Robertson
Agriculture and Food
Regina
Phone: 306-787-2359

AGRICULTURE KNOWLEDGE CENTRE BULLETIN: BLUE-GREEN ALGAE ALERT

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