The Community Association Institute West Florida Chapter recently published the following article in their Community magazine that Aquatic Systems President, John Gardner penned for HOA and Community Board members about lake algae.
Algae can make the water green and slimy in Florida freshwater lakes. However, algae are essential to the ecosystem, providing oxygen and food for all types of aquatic animals including fish, insects, mollusks and zooplankton (microscopic animals). Algae occur naturally in all types of ponds, lakes and waterways and are a biological indicator of an ecosystem’s health.
Starting early in the year, rainfall decreases each week until we are in our annual dry season and pretty much rain free. For people, it means perfect sunny and low humidity weather every day.
As the year progresses through spring, air temperatures rise and evaporation increases. Lake water evaporates and does not get replaced through rain. Water levels recede while water temperatures rise. When that happens, the concentration of nutrients increases and dissolved oxygen decreases throughout the water column. Dissolved nutrients, especially phosphorus and nitrogen , are a feast for algae fueling their growth. As spring progresses into summer, algae, bacteria and other plants continually multiply, spread and die releasing additional nutrients and strengthening the vicious algae growth cycle.
Bone Valley, which runs through central west Florida is the largest natural deposit of Phosphorus in the world and your retention pond may be sitting on top of it!
Here comes our normally hot and wet rainy season when conditions are ideal for excessive algae growth. You might think that rising lake levels would diminish excessive algae growth, and it may for a few days following heavy rains, but then the algae growth returns. Our rain typically arrives in the form of quick thunderstorm bursts which wash watershed detritus, chemicals and nutrients directly into our lakes.
Many communities have engineered storm water retention lakes that were designed to hold rainwater runoff to prevent local flooding, while simultaneously capturing and filtering out nutrients and pollutants before discharging cleaner water offsite into the local water management drainage system. Older storm water lakes that have trapped phosphorus runoff for decades, and those lakes receiving reclaimed wastewater often have the highest levels of phosphorus and nitrogen that favors development of another type of organism commonly mistaken for algae: cyanobacteria, sometimes referred to as blue-green algae.
Cyanobacteria, or blue-green algae, typically grow in two different forms: free-floating colonies which make the water look like pea soup or filamentous mats that float on top. Adverse environmental conditions sometimes trigger a defense mechanism that causes the cyanobacteria to discharge harmful toxins into surrounding waters. The only way to know with certainty if a cyanobacteria bloom is toxic is to have it properly identified and the water tested by qualified professionals.
What Can you do to Fight Algae Problems? Reduce Nutrients!
Modern, progressive lake management companies help manage algae and cyanobacteria blooms by improving water quality and rely less on frequent reapplications of algaecides and herbicides.
- Test your lake’s water quality to understand the underlying issues causing undesirable algae blooms. A comprehensive lake assessment report that provides water analysis and recommends sustainable solutions is surprisingly affordable and available from a competent lake management company.
- Phosphorus pollution is often the main reason for algae blooms, so a healthy, renewable lake management program should be focused on using available technologies to reduce or deactivate the lake’s soluble phosphorus level.
- Add dissolved oxygen to your lake with the addition of a bottom aeration system. Aeration increases water circulation throughout the water column helping reduce phosphorus, nitrogen, ammonia, hydrogen sulfide and carbon dioxide to promote cleaner, clearer water and higher levels of healthy bacteria, fish and plants that keep the entire ecosystem in balance.
- Do whatever possible to reduce watershed pollutants from draining into the lake. Prohibit the use of phosphorus fertilizers, prevent grass clippings and other landscape materials from entering the lake and ask residents to pick-up after their pets.
Managing freshwater lakes in Florida’s unique weather conditions can be a year around challenge but with proper use of science and technology, an eco-friendly, sustainable lake management solution for keeping your lakes in a healthy, beautiful condition can be achieved!
Are you seeing signs of algae blooms? Get help before it takes over!