Cyanobacteria, often referred to as blue-green algae, are changing the way lake and pond management professionals approach algae control in lakes and ponds.
Harmful Algal Bloom (HAB) treatments reached an all-time high in 2018. HABs have the potential to be highly toxic and can seriously impact the health and well-being of nearby humans, pets, and wildlife.
The devastating effects of harmful algal blooms have been witnessed repeatedly throughout the U.S. over the past 10 years. No area of the country is safe from the threat of HABs, as two catastrophes from very different parts of the country show us.
We can, however, learn from these natural disasters and use proactive lake management strategies to help avoid them in the future.
How Toxic Algal Blooms Have Impacted Lakes Nationwide
Toxic algae have plagued Florida’s largest freshwater lake, Lake Okeechobee, over the past several years. Cyanobacteria cover almost the entire lake each summer and transform the beautiful aquatic ecosystem into a thick green pea-soup color.
Why are toxic algal blooms dangerous?
- Produce toxins
- Can become airborne
- Harm fish and wildlife
- Can contaminate drinking water
- Limit recreation
The polluted waters of Lake Okeechobee are not just contained to the lake; they pollute everything downstream, including the St. Lucie River and Caloosahatchee River.
Eventually, these systems dump the toxic algae along Florida’s east and west shorelines, polluting these once beautiful tourist destinations with a thick brown sludge that severely limits access to swimming and fishing.
Massive harmful algal blooms don’t just occur in warm regions of the south. Many people are familiar with Lake Erie and remember the media attention around the massive blue-green algae outbreaks of 2011 and 2015. These blooms directly impacted drinking water supplies for surrounding cities like Toledo, OH.
Can Blue-Green Algae Make People Sick?
Yes, in some cases, humans can get sick after being exposed to blue-green algae.
Symptoms can include:
- Liver and kidney toxicity
- Skin rashes
- Nervous system problems
- Respiratory complications
Even more concerning than the immediate health effects of cyanotoxins is a growing connection between blue-green algae and diseases such as ALS, Alzheimer’s disease, and Parkinson’s disease.
Studies have found a direct link between these diseases and BMAA, a nerve toxin produced by cyanobacteria. The blue-green algae capable of making BMAA can be found in almost any waterbody, even those as small as a stormwater pond or ditch.
What Causes Toxic Algal Blooms?
Many factors contribute to algae growth, including:
- Temperature
- Sunlight
- Carbon dioxide
However, nutrients are the primary driver separating a balanced waterbody from a harmful algal bloom event.
Key sources of nutrient pollution:
- Urban development
- Industrial activity
- Agricultural waste
- Fertilizers from residential lawns
- Commercial turfgrass runoff
Stormwater now carries large amounts of nutrients into lakes and ponds. These waterbodies were never meant to handle that much pollution.
At the same time, wetlands that once acted as natural filters have been replaced by roads, sidewalks, and other hard surfaces.
How to Identify Blue-Green Algae and Harmful Algal Blooms
Proper identification of HABs is crucial. A lake management professional can confirm a harmful algal bloom through water quality testing.
Water quality analysis can:
- Identify the species causing the bloom
- Confirm whether toxins are present
- Identify underlying water quality imbalances
SOLitude uses state-of-the-art laboratory analysis to reveal potential water quality imbalances that can encourage HABs to develop. Once identified, steps can be taken to proactively minimize the issue and prevent future algal outbreaks.
How Can Harmful Algal Blooms Be Prevented?
While harmful algal blooms are becoming more common, they are not inevitable. Routine monitoring, early detection, and proactive lake management can dramatically reduce their frequency and severity.
Shoreline management: Creating a living shoreline of beneficial native plants around lakes and ponds further protects them from erosion and runoff. Deteriorated shorelines can be restored using bioengineering techniques that provide many years of stability.
Fountains and aerators: Installing floating fountains, surface aerators, or submersed aerators can help provide an oxygen-rich aquatic environment, which leads to improved water quality.
Nutrient remediation: Environmentally friendly products like aluminum sulfate (alum) and lanthanum-modified clay can be applied to the water column to “deactivate” undesirable nutrients, thus preventing them from fueling the growth of aquatic weeds or algae.
Beneficial bacteria: Beneficial biological bacteria can be applied to help decompose dead plant materials, muck, and nutrient-rich matter that fuel HABs.
Ecosystem restoration: This approach helps increase oxygen levels in bottom sediments, accelerating the breakdown of nutrient-rich organic matter. It can reduce nutrient levels by 50% to 90%, depending on site conditions and the restoration methods used.
Mechanical hydro-raking: Physically removing nutrient-rich muck and sludge from lake bottoms using a mechanical hydro-rake can help provide the same benefits, while “turning back time” on the aquatic resource to help increase water volume and depth.
Daily habits: A significant portion of nutrient pollution comes from everyday human activity and cultural habits. Individual actions that help prevent excess nutrients from entering nearby waterbodies:
- Properly dispose of pet waste
- Reduce fertilizer use
- Improve recycling habits
- Dispose of grass clippings and leaves properly
Reducing Future Toxic Algal Blooms
The harmful algal blooms that made headlines at Lake Okeechobee and Lake Erie were unfortunate, but also valuable learning opportunities. They reinforced what Aquatic Experts have long understood – that protecting water quality starts long before a bloom appears. By learning from these examples and taking a proactive management approach, we can help prevent history from repeating itself.
Manage Nutrients In Your Waterbody
Help manage pollutants in your lake or pond through nutrient management.
SOLitude Lake Management is a nationwide environmental firm committed to providing sustainable solutions that improve water quality, enhance beauty, preserve natural resources and reduce our environmental footprint. SOLitude’s team of aquatic resource management professionals specializes in the development and execution of customized lake, stormwater pond, wetland and fisheries management programs that include water quality testing and restoration, nutrient remediation, algae and aquatic weed control, installation and maintenance of fountains and aeration systems, bathymetry, shoreline erosion restoration, mechanical harvesting and hydro-raking, lake vegetation studies, biological assessments, habitat evaluations, and invasive species management. Services and educational resources are available to clients nationwide, including homeowners associations, multi-family and apartment communities, golf courses, commercial developments, ranches, private landowners, reservoirs, recreational and public lakes, municipalities, drinking water authorities, parks, and state and federal agencies. SOLitude Lake Management is a proud member of the Rentokil Steritech family of companies in North America.
