You may have seen in the news recently about the three dogs in North Carolina who died from exposure to blue-green algae after a day of swimming at a pond. Blue-green algae blooms are microscopic bacteria that occur naturally on the surface. When the environment is just right, blue-green algae will thrive.
Blue-green algae blooms can create toxins that may be harmful to humans, pets, livestock, wildlife, and fish. There are many types of algae that are harmless to the environment and people around it but this specific type of algae can affect the nervous system and the liver. Other health effects include rashes, eye irritation, and gastrointestinal problems. In the most severe cases serious illness or death could occur depending on exposure.
Not all blue-green algae produce toxins and there is no way to predict the life cycle of these types of algae. The recent increase in blue-green algae is probably directly related to a high amount of nutrients from fertilizers, increased goose populations, and increased temperatures.
In terms of treatment, there isn’t really anything that can be done or should be done. Treatments of blue-green algae are not recommended as the death of this algae may be correlated with the release of the toxins. When the toxins are released, this is when it can be harmful to people and other wildlife.
One of the best ways to deal with blue-green algae is to be educated and monitor any warnings that may be out for public waters. The best way to avoid ill effects from a blue-green algae bloom is to stay away from the water and do not eat fish from the water that has been affected. Blue-green algae can be present in increasingly high quantities making swimming and boating hazardous. Precautions such as avoiding contact with visible algae and swallowing water while swimming should be taken. Also, be sure to wash with warm water and soap after coming in contact with bodies of water that are untreated. Keep pets and livestock away from untreated water.
Algae grows and thrives when there is an excess of phosphorous in the water. One of the best ways to neutralize some of these naturally occurring nutrients is to introduce high levels of "good bacteria". Bacteria will help consume organic material and cut back on the amount of phosphorous in the water. To begin with, nutrient levels must be reduced by using bacteria and bacterial enzymes. Sanco suggests Natural Pond Cleaner at the labeled rate of 1 gallon per surface acre once every two weeks or once a month, depending on the nutrient load. If caught early, treatment with chelated copper will be able to kill of the blue-green algae. Toxins will be released, but they will be in much smaller amounts that will do little to no harm.
Keep in mind that Oscillatoria and other blue-green algae only achieve superiority due to the elimination of competition; otherwise, they are subjected to the growth of other strains of algae and submerged weeds. Allowing other desirable algae groups, such as Chara or Nitella, to persist could aid in prevention of blue-greens. We have noted that in ponds where Chara and Nitella are managed rather than eliminated, we do not have problems with blue-green algae blooms.
In conclusion, be cautious when it comes to untreated bodies of water. If blue-green algae is present, stay out of the water and make sure that pets are kept out and away from swimming or drinking the water. If you or your pet come into contact with blue-green algae, scrub with soap and rinse off right away with clean water.