Controlling Dangerous Toxic Cyanobacteria
April 25th, 2016
Written by Industry Expert, Derek Johnson, Certified Lake Manager and Fisheries and Wildlife Scientist
Excessive cyanobacteria growth has become a serious nuisance and concern in our lakes and ponds across the nation. Commonly referred to as blue-green algae, they are best known for their blooms that have the appearance of spilled paint. Blue-green algae can grow quickly when the water is warm and enriched with nutrients. There are many different species, but the most commonly detected is Anabaena, Aphanizomenon, Microcystis, and Planktothrix. However, multiple species can create a bloom in a waterbody, and the dominant species can change over the course of the season.
Listen to Industry Expert Chris Doyle explain cyanobacteria:
Many species of blue-green algae have evolved to control their buoyancy. As the availability of light and nutrients change with the time of day and weather conditions, an algal cell is able to move up and down water depths. At night, when there is no light, cells are unable to adjust their buoyancy and often float to the surface, forming a surface bloom. This means that an algae bloom can literally appear overnight and stay on the surface until wind and waves are able to scatter the cells throughout the waterbody and dissipate the bloom.
Common concerns associated with blue-green algae are taste and odor compounds and toxin production causing drinking water contamination. Taste and odor compounds are responsible for most complaints when a blue-green algae bloom is present. An “earthy” odor emanating from a waterbody is indicative of the compound, geosmin. Some of the more dangerous compounds that could potentially be produced are neurotoxins (nerve damage), hepatoxins (liver damage), and endotoxins (skin irritants). Toxins are naturally produced chemical compounds within the cells. When the cells are broken open, the toxins are released into the water. This could result in a substantial concentration of the toxins in the water and lead to health issues in humans and surrounding wildlife. Even when the blue-green algae is no longer visible, toxins may be present for some period of time. The only way to determine if these toxins are present is to have water samples collected and analyzed in a laboratory.
There are no quick fixes for the control of blue-green algae once they appear in a lake or pond. Using an algaecide and water quality enhancer in the early stages of a bloom may help to limit the growth and help mitigate excessive nutrients in the waterbody. Eventually, by reducing the overall amount of nutrients within a waterbody, bloom frequency and intensity may be reduced. However, it may take a long time to effectively change the nutrient concentrations in a waterbody. Inputs from the watershed that enter a lake or pond every year will lead to large amounts of phosphorous in the sediment. The nutrients will continue to serve as a source of food for the blue-green algae and lead to future, potentially larger, blooms. There are phosphorus binding compounds that can be applied to your waterbody to help reduce the available “food source” for algae.
Another approach to prevent the nutrients from becoming available to the blue-green algae is the installation of submersed aeration. Adding oxygen at the bottom of a lake or pond will act as the glue that will help bind the nutrients (phosphorous) to the iron in the sediment and keep it inaccessible to the blue-green algae.
SonicSolutions technology, which uses sound waves at a specific vibration frequency to disrupt the cell walls of the algae (similar to how an opera singer can shatter a glass by using their voice), can also be used. In essence, the sound waves will cause the algal cells to shrivel up without breaking apart and releasing the potentially dangerous toxins. This may be a safe alternative in certain situations where a large die off of blue-green algae would be dangerous due to the simultaneous toxic release.
SOLitude Lake Management has the tools, experience, and expertise to help prevent and control a potentially dangerous blue-green algae bloom. Educating residents and managers to use best management practices can also promote awareness and minimize a bloom: using lawn fertilizers only where truly needed, preventing yard debris (e.g., leaves, grass clippings, etc.) from washing into storm drains and waterbodies, and planting native vegetation along shorelines of lakes, ponds and streams are just a few examples. Precautions should always be taken when there are blue-green algae present in a waterbody and residents should wait for a bloom to dissipate before going in or near the water.
Contact the experts at 888-480-LAKE (5253) for all of your lake, pond and fisheries management needs.
Derek Johnson is Certified Lake Manager and Fisheries and Wildlife Scientist with SOLitude Lake Management. SOLitude Lake Management is committed to providing full service lake and pond management services that improve water quality, preserve natural resources, and reduce our environmental footprint. Lake, pond and fisheries management services, consulting, and aquatic products are available nationwide. Learn more about SOLitude Lake Management and purchase products at www.solitudelakemanagement.com.